7.1.0.4

agent: fast queue rotation not requiring the current server to be online (#1847 )
* agent: fast queue rotation does not requiring the current server to be online * update plan * update plan and rfc * corrections * update plan * implementation * test * refactor * test switching notificaitons * rename * fix, refactor * fix possible crash * simplify * refactor * simplify * refactor * simplify * order, avoid re-reading connection --------- Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>
2026-08-31 07:28:23 +00:00 · 2026-08-20 09:33:10 +01:00 · 2026-08-20 09:02:41 +01:00 · 2026-08-18 13:57:10 +01:00 · 2026-08-17 12:51:45 +01:00 · 2026-08-12 18:39:03 +01:00
173 changed files with 15547 additions and 3749 deletions
@@ -24,6 +24,8 @@ jobs:
      - name: Clone project
        if: startsWith(github.ref, 'refs/tags/v')
        uses: actions/checkout@v3
+        with:
+          submodules: recursive

      - name: Build changelog
        id: build_changelog
@@ -114,6 +116,8 @@ jobs:
      - name: Clone project
        if: matrix.should_run == true
        uses: actions/checkout@v3
+        with:
+          submodules: recursive

      - name: Set up Docker Buildx
        if: matrix.should_run == true
@@ -173,7 +177,7 @@ jobs:
            -v ${{ github.workspace }}:/project \
            build/${{ matrix.os }}:latest

-      - name: Build smp-server (postgresql) and tests
+      - name: Build smp-server, xftp-server (postgresql) and tests
        if: matrix.should_run == true
        shell: docker exec -t builder sh -eu {0}
        run: |
@@ -182,12 +186,12 @@ jobs:
          cabal update
          cabal build --jobs=$(nproc) --enable-tests -fserver_postgres
          mkdir -p /out
-          for i in smp-server simplexmq-test; do
+          for i in smp-server xftp-server simplexmq-test; do
            bin=$(find /project/dist-newstyle -name "$i" -type f -executable)
            chmod +x "$bin"
            mv "$bin" /out/
          done
-          strip /out/smp-server
+          strip /out/smp-server /out/xftp-server

      - name: Copy simplexmq-test from container
        if: matrix.should_run == true
@@ -195,19 +199,29 @@ jobs:
        run: |
          docker cp builder:/out/simplexmq-test .

-      - name: Copy smp-server (postgresql) from container and prepare it
+      - name: Copy smp-server, xftp-server (postgresql) from container and prepare it
        if: startsWith(github.ref, 'refs/tags/v') && matrix.should_run == true
        id: prepare-postgres
        shell: bash
        run: |
-          name="smp-server-postgres-ubuntu-${{ matrix.os_underscore }}-${{ matrix.arch }}"
-          docker cp builder:/out/smp-server $name
+          printf 'bins<<EOF\n' > bins.output
+          printf 'hashes<<EOF\n' > hashes.output

-          path="${{ github.workspace }}/$name"
-          echo "bin=$path" >> $GITHUB_OUTPUT
+          for i in smp-server xftp-server; do
+            name="${i}-postgres-ubuntu-${{ matrix.os_underscore }}-${{ matrix.arch }}"
+            docker cp builder:/out/$i $name

-          hash="SHA2-256($name)= $(openssl sha256 $path | cut -d' ' -f 2)"
-          printf 'hash=%s' "$hash" >> $GITHUB_OUTPUT
+            path="${{ github.workspace }}/$name"
+            hash="SHA2-256($name)= $(openssl sha256 $path | cut -d' ' -f 2)"
+
+            printf '%s\n' "$path" >> bins.output
+            printf '%s\n\n' "$hash" >> hashes.output
+          done
+          printf 'EOF\n' >> bins.output
+          printf 'EOF\n' >> hashes.output
+
+          cat bins.output >> "$GITHUB_OUTPUT"
+          cat hashes.output >> "$GITHUB_OUTPUT"

      - name: Build everything else (standard)
        if: matrix.should_run == true
@@ -257,10 +271,10 @@ jobs:
          fail_on_unmatched_files: true
          body: |
            ${{ steps.prepare-regular.outputs.hashes }}
-            ${{ steps.prepare-postgres.outputs.hash }}
+            ${{ steps.prepare-postgres.outputs.hashes }}
          files: |
            ${{ steps.prepare-regular.outputs.bins }}
-            ${{ steps.prepare-postgres.outputs.bin }}
+            ${{ steps.prepare-postgres.outputs.bins }}
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

@@ -20,6 +20,8 @@ jobs:
    steps:
      - name: Clone project
        uses: actions/checkout@v4
+        with:
+          submodules: recursive

      - name: Log in to Docker Hub
        uses: simplex-chat/docker-login-action@v3
@@ -11,6 +11,8 @@ jobs:
    steps:
      - name: Checkout code
        uses: actions/checkout@v3
+        with:
+          submodules: recursive

      - name: Get latest release
        shell: bash
@@ -0,0 +1,6 @@
+[submodule "cbits/libbbs"]
+	path = cbits/libbbs
+	url = https://github.com/simplex-chat/libbbs.git
+[submodule "cbits/blst"]
+	path = cbits/blst
+	url = https://github.com/supranational/blst.git
@@ -1,3 +1,39 @@
+# 6.5.1
+
+Version 6.5.1.0
+
+XFTP client:
+- backwards compatible file header decoding.
+
+# 6.5.0
+
+Version 6.5.0.17
+
+SMP agent:
+- improve subscriptions
+  - reduce memory usage and retries during initial subscription (#1758)
+  - fix race resulting in pending subscriptions never subscribed (#1756)
+  - batch processing of subscription results and errors (#1652)
+  - reduce memory usage of active subscriptions.
+- drop message after N reception attempts (#1762)
+- fix possible deadlocks of queue overloading when processing messages (#1713)
+- improved APIs for short link management and creation.
+- support multiple link owners in link data (#1701)
+
+SMP server:
+- store messages in PostgreSQL (#1622).
+- reduce memory usage with PostgreSQL database - do not use queue cache (#1637)
+- fix in-memory server not restoring queue/service associations after 2+ restarts (#1618)
+
+XFTP server:
+- support PostgreSQL database.
+- add server page.
+- support uploads from web clients.
+
+Servers:
+- better socket leak prevention during TLS handshake, NetworkError type to bette diagnose connection errors (#1619)
+- use "=" as default INI key-value separator (#1767)
+
 # 6.4.4

 Servers:
@@ -33,7 +33,7 @@ To initialize the server use `smp-server init -n <fqdn>` (or `smp-server init --

 SMP server uses in-memory persistence with an optional append-only log of created queues that allows to re-start the server without losing the connections. This log is compacted on every server restart, permanently removing suspended and removed queues.

-To enable store log, initialize server using `smp-server -l` command, or modify `smp-server.ini` created during initialization (uncomment `enable: on` option in the store log section). Use `smp-server --help` for other usage tips.
+To enable store log, initialize server using `smp-server -l` command, or modify `smp-server.ini` created during initialization (uncomment `enable = on` option in the store log section). Use `smp-server --help` for other usage tips.

 Starting from version 2.3.0, when store log is enabled, the server would also enable saving undelivered messages on exit and restoring them on start. This can be disabled via a separate setting `restore_messages` in `smp-server.ini` file. Saving messages would only work if the server is stopped with SIGINT signal (keyboard interrupt), if it is stopped with SIGTERM signal the messages would not be saved.

@@ -105,13 +105,13 @@
                    class="text-[16px] leading-[26px] tracking-[0.01em] nav-link-text text-black dark:text-white before:bg-black dark:before:bg-white">Server
                    information</span></a>
              </li>
-              <x-xftpConfig>
+              <!-- <x-xftpConfig>
              <li class="nav-link relative"><a href="/file"
                  class="flex items-center justify-between gap-2 lg:py-5 whitespace-nowrap"><span
                    class="text-[16px] leading-[26px] tracking-[0.01em] nav-link-text text-black dark:text-white before:bg-black dark:before:bg-white">File
                    transfer</span></a>
              </li>
-              </x-xftpConfig>
+              </x-xftpConfig> -->
            </ul><a target="_blank" href="https://github.com/simplex-chat/simplex-chat#help-us-with-donations"
              class="whitespace-nowrap flex items-center gap-1 self-center text-white dark:text-black text-[16px] font-medium tracking-[0.02em] rounded-[34px] bg-primary-light dark:bg-primary-dark py-3 lg:py-2 px-20 lg:px-5 mb-16 lg:mb-0">Donate</a>
          </div>
@@ -34,7 +34,7 @@ xftpMediaContent = $(embedDir "apps/xftp-server/static/media/")
 xftpFilePageHtml :: ByteString
 xftpFilePageHtml = $(embedFile "apps/xftp-server/static/file.html")

-xftpGenerateSite :: XFTPServerConfig -> Maybe ServerPublicInfo -> Maybe TransportHost -> FilePath -> IO ()
+xftpGenerateSite :: XFTPServerConfig s -> Maybe ServerPublicInfo -> Maybe TransportHost -> FilePath -> IO ()
 xftpGenerateSite cfg info onionHost path = do
  let substs = xftpSubsts cfg info onionHost
  Web.generateSite embeddedContent (render (Web.indexHtml embeddedContent) substs) [] path
@@ -50,10 +50,10 @@ xftpGenerateSite cfg info onionHost path = do
      createDirectoryIfMissing True dir
      forM_ content_ $ \(fp, content) -> B.writeFile (dir </> fp) content

-xftpServerInformation :: XFTPServerConfig -> Maybe ServerPublicInfo -> Maybe TransportHost -> ByteString
+xftpServerInformation :: XFTPServerConfig s -> Maybe ServerPublicInfo -> Maybe TransportHost -> ByteString
 xftpServerInformation cfg info onionHost = render (Web.indexHtml embeddedContent) (xftpSubsts cfg info onionHost)

-xftpSubsts :: XFTPServerConfig -> Maybe ServerPublicInfo -> Maybe TransportHost -> [(ByteString, Maybe ByteString)]
+xftpSubsts :: XFTPServerConfig s -> Maybe ServerPublicInfo -> Maybe TransportHost -> [(ByteString, Maybe ByteString)]
 xftpSubsts XFTPServerConfig {fileExpiration, logStatsInterval, allowNewFiles, newFileBasicAuth} information onionHost =
  [("smpConfig", Nothing), ("xftpConfig", Just "y")] <> substConfig <> serverInfoSubsts simplexmqSource information <> [("onionHost", strEncode <$> onionHost), ("iniFileName", Just "file-server.ini")]
  where
@@ -619,7 +619,6 @@ async function handleEncrypt(id, data, fileName) {
  const digest = sha512Streaming([encData], (done) => {
    self.postMessage({ id, type: "progress", done: source.length + done, total });
  }, encDataLen);
-  console.log(`[WORKER-DBG] encrypt: encData.len=${encData.length} digest=${_whex(digest, 64)} chunkSizes=[${chunkSizes.join(",")}]`);
  const dir = await getSessionDir();
  const fileHandle = await dir.getFileHandle("upload.bin", { create: true });
  const writeHandle = await fileHandle.createSyncAccessHandle();
@@ -643,9 +642,7 @@ function handleReadChunk(id, offset, size) {
 }
 async function handleDecryptAndStore(id, dhSecret, nonce, body, chunkDigest, chunkNo) {
  const bodyArr = new Uint8Array(body);
-  console.log(`[WORKER-DBG] store chunk=${chunkNo} body.len=${bodyArr.length} nonce=${_whex(nonce, 24)} dhSecret=${_whex(dhSecret)} digest=${_whex(chunkDigest, 32)} body[0..8]=${_whex(bodyArr)} body[-8..]=${_whex(bodyArr.slice(-8))}`);
  const decrypted = decryptReceivedChunk(dhSecret, nonce, bodyArr, chunkDigest);
-  console.log(`[WORKER-DBG] decrypted chunk=${chunkNo} len=${decrypted.length} [0..8]=${_whex(decrypted)} [-8..]=${_whex(decrypted.slice(-8))}`);
  if (useMemory) {
    memoryChunks.set(chunkNo, decrypted);
    self.postMessage({ id, type: "stored" });
@@ -660,7 +657,6 @@ async function handleDecryptAndStore(id, dhSecret, nonce, body, chunkDigest, chu
  currentDownloadOffset += decrypted.length;
  chunkMeta.set(chunkNo, { offset, size: decrypted.length });
  const written = downloadWriteHandle.write(decrypted, { at: offset });
-  console.log(`[WORKER-DBG] OPFS write chunk=${chunkNo} offset=${offset} size=${decrypted.length} written=${written}`);
  if (written !== decrypted.length) {
    console.warn(`[WORKER] OPFS write failed chunk=${chunkNo}: ${written}/${decrypted.length}, falling back to in-memory storage`);
    for (const [cn, meta] of chunkMeta.entries()) {
@@ -684,23 +680,16 @@ async function handleDecryptAndStore(id, dhSecret, nonce, body, chunkDigest, chu
    return;
  }
  downloadWriteHandle.flush();
-  const verifyBuf = new Uint8Array(Math.min(8, decrypted.length));
-  downloadWriteHandle.read(verifyBuf, { at: offset });
-  const verifyEnd = new Uint8Array(Math.min(8, decrypted.length));
-  downloadWriteHandle.read(verifyEnd, { at: offset + decrypted.length - verifyEnd.length });
-  console.log(`[WORKER-DBG] OPFS verify chunk=${chunkNo} readBack[0..8]=${_whex(verifyBuf)} readBack[-8..]=${_whex(verifyEnd)} expected[0..8]=${_whex(decrypted)} expected[-8..]=${_whex(decrypted.slice(-8))}`);
  self.postMessage({ id, type: "stored" });
 }
 async function handleVerifyAndDecrypt(id, size, digest, key, nonce) {
-  console.log(`[WORKER-DBG] verify: expectedSize=${size} expectedDigest=${_whex(digest, 64)} useMemory=${useMemory} chunkMeta.size=${chunkMeta.size} memoryChunks.size=${memoryChunks.size}`);
  const chunks = [];
  let totalSize = 0;
  const total = size * 3;
  let done = 0;
  if (useMemory) {
    const sorted = [...memoryChunks.entries()].sort((a, b) => a[0] - b[0]);
-    for (const [chunkNo, data] of sorted) {
-      console.log(`[WORKER-DBG] verify memory chunk=${chunkNo} size=${data.length}`);
+    for (const [, data] of sorted) {
      chunks.push(data);
      totalSize += data.length;
      done += data.length;
@@ -715,12 +704,10 @@ async function handleVerifyAndDecrypt(id, size, digest, key, nonce) {
    const dir = await getSessionDir();
    const fileHandle = await dir.getFileHandle("download.bin");
    const readHandle = await fileHandle.createSyncAccessHandle();
-    console.log(`[WORKER-DBG] verify: OPFS file size=${readHandle.getSize()}`);
    const sortedEntries = [...chunkMeta.entries()].sort((a, b) => a[0] - b[0]);
-    for (const [chunkNo, meta] of sortedEntries) {
+    for (const [, meta] of sortedEntries) {
      const buf = new Uint8Array(meta.size);
-      const bytesRead = readHandle.read(buf, { at: meta.offset });
-      console.log(`[WORKER-DBG] verify read chunk=${chunkNo} offset=${meta.offset} size=${meta.size} bytesRead=${bytesRead} [0..8]=${_whex(buf)} [-8..]=${_whex(buf.slice(-8))}`);
+      readHandle.read(buf, { at: meta.offset });
      chunks.push(buf);
      totalSize += meta.size;
      done += meta.size;
@@ -745,20 +732,9 @@ async function handleVerifyAndDecrypt(id, size, digest, key, nonce) {
  }
  const actualDigest = r.crypto_hash_sha512_final(state);
  if (!digestEqual(actualDigest, digest)) {
-    console.error(`[WORKER-DBG] DIGEST MISMATCH: expected=${_whex(digest, 64)} actual=${_whex(actualDigest, 64)} chunks=${chunks.length} totalSize=${totalSize}`);
-    const state2 = r.crypto_hash_sha512_init();
-    for (let i = 0; i < chunks.length; i++) {
-      const chunk = chunks[i];
-      for (let off = 0; off < chunk.length; off += hashSEG) {
-        r.crypto_hash_sha512_update(state2, chunk.subarray(off, Math.min(off + hashSEG, chunk.length)));
-      }
-      const chunkDigest = sha512Streaming([chunk]);
-      console.error(`[WORKER-DBG] chunk[${i}] size=${chunk.length} sha512=${_whex(chunkDigest, 32)}… [0..8]=${_whex(chunk)} [-8..]=${_whex(chunk.slice(-8))}`);
-    }
    self.postMessage({ id, type: "error", message: "File digest mismatch" });
    return;
  }
-  console.log(`[WORKER-DBG] verify: digest OK`);
  const result = decryptChunks(BigInt(size), chunks, key, nonce, (d) => {
    self.postMessage({ id, type: "progress", done: size * 2 + d, total });
  });
@@ -334,11 +334,6 @@ class WorkerBackend {
    const nonceCopy = new Uint8Array(nonce);
    const digestCopy = new Uint8Array(digest);
    const buf = this.toTransferable(body);
-    const hex = (b, n = 8) => {
-      const u = b instanceof ArrayBuffer ? new Uint8Array(b) : b;
-      return Array.from(u.slice(0, n)).map((x) => x.toString(16).padStart(2, "0")).join("");
-    };
-    console.log(`[BACKEND-DBG] chunk=${chunkNo} body.len=${body.length} body.byteOff=${body.byteOffset} buf.byteLen=${buf.byteLength} nonce=${hex(nonceCopy, 24)} dhSecret=${hex(dhSecretCopy)} digest=${hex(digestCopy, 32)} buf[0..8]=${hex(buf)} body[-8..]=${hex(body.slice(-8))}`);
    await this.send(
      { type: "decryptAndStoreChunk", dhSecret: dhSecretCopy, nonce: nonceCopy, body: buf, chunkDigest: digestCopy, chunkNo },
      [buf]
@@ -10913,14 +10908,12 @@ async function sendXFTPCommandOnce(client, privateKey, entityId, cmdBytes, chunk
  const block = encodeAuthTransmission(client.sessionId, corrId, entityId, cmdBytes, privateKey);
  const reqBody = chunkData ? concatBytes$1(block, chunkData) : block;
  const fullResp = await client.transport.post(reqBody);
-  console.log(`[XFTP-DBG] sendOnce: fullResp.length=${fullResp.length} entityId=${_hex(entityId)} cmdTag=${cmdBytes[0]}`);
  if (fullResp.length < XFTP_BLOCK_SIZE) {
    console.error("[XFTP] Response too short: %d bytes (expected >= %d)", fullResp.length, XFTP_BLOCK_SIZE);
    throw new Error("Server response too short");
  }
  const respBlock = fullResp.subarray(0, XFTP_BLOCK_SIZE);
  const body = fullResp.subarray(XFTP_BLOCK_SIZE);
-  console.log(`[XFTP-DBG] sendOnce: body.length=${body.length} body.byteOffset=${body.byteOffset} body.buffer.byteLength=${body.buffer.byteLength}`);
  const raw = blockUnpad(respBlock);
  if (raw.length < 20) {
    const text = new TextDecoder().decode(raw);
@@ -10939,18 +10932,13 @@ async function sendXFTPCommandOnce(client, privateKey, entityId, cmdBytes, chunk
  }
  return { response, body };
 }
-function _hex(b, n = 8) {
-  return Array.from(b.slice(0, n)).map((x) => x.toString(16).padStart(2, "0")).join("");
-}
 async function sendXFTPCommand(agent, server, privateKey, entityId, cmdBytes, chunkData, maxRetries = 3) {
  let clientP = getXFTPServerClient(agent, server);
  let client = await clientP;
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
-      if (attempt > 1) console.log(`[XFTP-DBG] sendCmd: retry attempt=${attempt}/${maxRetries}`);
      return await sendXFTPCommandOnce(client, privateKey, entityId, cmdBytes, chunkData);
    } catch (e) {
-      console.log(`[XFTP-DBG] sendCmd: attempt=${attempt} failed: ${e instanceof Error ? e.message : String(e)} retriable=${isRetriable(e)}`);
      if (!isRetriable(e)) {
        throw categorizeError(e);
      }
@@ -10979,7 +10967,6 @@ async function downloadXFTPChunkRaw(agent, server, rpKey, fId) {
  const { response, body } = await sendXFTPCommand(agent, server, rpKey, fId, cmd);
  if (response.type !== "FRFile") throw new Error("unexpected response: " + response.type);
  const dhSecret = dh(response.rcvDhKey, privateKey);
-  console.log(`[XFTP-DBG] dlChunkRaw: body.length=${body.length} nonce=${_hex(response.nonce, 24)} dhSecret=${_hex(dhSecret)} body[0..8]=${_hex(body)} body[-8..]=${_hex(body.slice(-8))}`);
  return { dhSecret, nonce: response.nonce, body };
 }
 async function downloadXFTPChunk(agent, server, rpKey, fId, digest) {
@@ -11012,7 +10999,6 @@ function encryptFileForUpload(source, fileName) {
  const encSize = BigInt(chunkSizes.reduce((a, b) => a + b, 0));
  const encData = encryptFile(source, fileHdr, key, nonce, fileSize, encSize);
  const digest = sha512Streaming([encData]);
-  console.log(`[AGENT-DBG] encrypt: encData.len=${encData.length} digest=${_dbgHex(digest, 64)} chunkSizes=[${chunkSizes.join(",")}]`);
  return { encData, digest, key, nonce, chunkSizes };
 }
 const DEFAULT_REDIRECT_THRESHOLD = 400;
@@ -11169,9 +11155,7 @@ async function downloadFileRaw(agent, fd, onRawChunk, options) {
  if (err) throw new Error("downloadFileRaw: " + err);
  const { onProgress} = options ?? {};
  if (fd.redirect !== null) {
-    console.log(`[AGENT-DBG] resolving redirect: outer size=${fd.size} chunks=${fd.chunks.length}`);
    fd = await resolveRedirect(agent, fd);
-    console.log(`[AGENT-DBG] resolved: size=${fd.size} chunks=${fd.chunks.length} digest=${Array.from(fd.digest.slice(0, 16)).map((x) => x.toString(16).padStart(2, "0")).join("")}…`);
  }
  const resolvedFd = fd;
  let downloaded = 0;
@@ -11189,7 +11173,6 @@ async function downloadFileRaw(agent, fd, onRawChunk, options) {
      const seed = decodePrivKeyEd25519(replica.replicaKey);
      const kp = ed25519KeyPairFromSeed(seed);
      const raw = await downloadXFTPChunkRaw(agent, server, kp.privateKey, replica.replicaId);
-      console.log(`[AGENT-DBG] chunk=${chunk.chunkNo} body.len=${raw.body.length} expectedChunkSize=${chunk.chunkSize} digest=${_dbgHex(chunk.digest, 32)} body.byteOffset=${raw.body.byteOffset} body.buffer.byteLength=${raw.body.buffer.byteLength}`);
      await onRawChunk({
        chunkNo: chunk.chunkNo,
        dhSecret: raw.dhSecret,
@@ -1,133 +0,0 @@
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE GADTs #-}
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE PatternSynonyms #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TupleSections #-}
-{-# LANGUAGE TypeApplications #-}
-{-# OPTIONS_GHC -fno-warn-ambiguous-fields #-}
-
-module ClientSim
-  ( SimClient (..),
-    connectClient,
-    createQueue,
-    subscribeQueue,
-    sendMessage,
-    receiveAndAck,
-    connectN,
-    benchKeyHash,
-  )
-where
-
-import Control.Concurrent.Async (mapConcurrently)
-import Control.Concurrent.STM
-import Control.Monad (forM_)
-import Control.Monad.Except (runExceptT)
-import Data.ByteString.Char8 (ByteString)
-import Data.List (unfoldr)
-import qualified Data.List.NonEmpty as L
-import Network.Socket (ServiceName)
-import qualified Simplex.Messaging.Crypto as C
-import Simplex.Messaging.Encoding
-import Simplex.Messaging.Protocol
-import Simplex.Messaging.Transport
-import Simplex.Messaging.Transport.Client
-import Simplex.Messaging.Version
-
-data SimClient = SimClient
-  { scHandle :: THandleSMP TLS 'TClient,
-    scRcvKey :: C.APrivateAuthKey,
-    scRcvId :: RecipientId,
-    scSndId :: SenderId,
-    scDhSecret :: C.DhSecret 'C.X25519
-  }
-
-benchKeyHash :: C.KeyHash
-benchKeyHash = "LcJUMfVhwD8yxjAiSaDzzGF3-kLG4Uh0Fl_ZIjrRwjI="
-
-connectClient :: TransportHost -> ServiceName -> IO (THandleSMP TLS 'TClient)
-connectClient host port = do
-  let tcConfig = defaultTransportClientConfig {clientALPN = Just alpnSupportedSMPHandshakes}
-  runTransportClient tcConfig Nothing host port (Just benchKeyHash) $ \h ->
-    runExceptT (smpClientHandshake h Nothing benchKeyHash supportedClientSMPRelayVRange False Nothing) >>= \case
-      Right th -> pure th
-      Left e -> error $ "SMP handshake failed: " <> show e
-
-connectN :: Int -> TransportHost -> ServiceName -> IO [THandleSMP TLS 'TClient]
-connectN n host port = do
-  let batches = chunksOf 100 [1 .. n]
-  concat <$> mapM (\batch -> mapConcurrently (\_ -> connectClient host port) batch) batches
-
-createQueue :: THandleSMP TLS 'TClient -> IO SimClient
-createQueue h = do
-  g <- C.newRandom
-  (rPub, rKey) <- atomically $ C.generateAuthKeyPair C.SEd448 g
-  (sPub, sKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g
-  (dhPub, dhPriv :: C.PrivateKeyX25519) <- atomically $ C.generateKeyPair g
-  -- NEW command
-  Resp "1" NoEntity (Ids rId sId srvDh) <- signSendRecv h rKey ("1", NoEntity, New rPub dhPub)
-  let dhShared = C.dh' srvDh dhPriv
-  -- KEY command (secure queue)
-  Resp "2" _ OK <- signSendRecv h rKey ("2", rId, KEY sPub)
-  pure SimClient {scHandle = h, scRcvKey = rKey, scRcvId = rId, scSndId = sId, scDhSecret = dhShared}
-
-subscribeQueue :: SimClient -> IO ()
-subscribeQueue SimClient {scHandle = h, scRcvKey = rKey, scRcvId = rId} = do
-  Resp "3" _ (SOK _) <- signSendRecv h rKey ("3", rId, SUB)
-  pure ()
-
-sendMessage :: THandleSMP TLS 'TClient -> C.APrivateAuthKey -> SenderId -> ByteString -> IO ()
-sendMessage h sKey sId body = do
-  Resp "4" _ OK <- signSendRecv h sKey ("4", sId, SEND noMsgFlags body)
-  pure ()
-
-receiveAndAck :: SimClient -> IO ()
-receiveAndAck SimClient {scHandle = h, scRcvKey = rKey, scRcvId = rId} = do
-  (_, _, Right (MSG RcvMessage {msgId = mId})) <- tGet1 h
-  Resp "5" _ OK <- signSendRecv h rKey ("5", rId, ACK mId)
-  pure ()
-
-- Helpers (same patterns as ServerTests.hs)
-
-pattern Resp :: CorrId -> EntityId -> BrokerMsg -> Transmission (Either ErrorType BrokerMsg)
-pattern Resp corrId queueId command <- (corrId, queueId, Right command)
-
-pattern Ids :: RecipientId -> SenderId -> RcvPublicDhKey -> BrokerMsg
-pattern Ids rId sId srvDh <- IDS (QIK rId sId srvDh _ _ Nothing Nothing)
-
-pattern New :: RcvPublicAuthKey -> RcvPublicDhKey -> Command 'Creator
-pattern New rPub dhPub = NEW (NewQueueReq rPub dhPub Nothing SMSubscribe (Just (QRMessaging Nothing)) Nothing)
-
-signSendRecv :: (Transport c, PartyI p) => THandleSMP c 'TClient -> C.APrivateAuthKey -> (ByteString, EntityId, Command p) -> IO (Transmission (Either ErrorType BrokerMsg))
-signSendRecv h pk t = do
-  signSend h pk t
-  (r L.:| _) <- tGetClient h
-  pure r
-
-signSend :: (Transport c, PartyI p) => THandleSMP c 'TClient -> C.APrivateAuthKey -> (ByteString, EntityId, Command p) -> IO ()
-signSend h@THandle {params} (C.APrivateAuthKey a pk) (corrId, qId, cmd) = do
-  let TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth params (CorrId corrId, qId, cmd)
-      authorize t = (,Nothing) <$> case a of
-        C.SEd25519 -> Just . TASignature . C.ASignature C.SEd25519 $ C.sign' pk t
-        C.SEd448 -> Just . TASignature . C.ASignature C.SEd448 $ C.sign' pk t
-        C.SX25519 -> (\THAuthClient {peerServerPubKey = k} -> TAAuthenticator $ C.cbAuthenticate k pk (C.cbNonce corrId) t) <$> thAuth params
-  Right () <- tPut1 h (authorize tForAuth, tToSend)
-  pure ()
-
-tPut1 :: Transport c => THandle v c 'TClient -> SentRawTransmission -> IO (Either TransportError ())
-tPut1 h t = do
-  rs <- tPut h (Right t L.:| [])
-  case rs of
-    (r : _) -> pure r
-    [] -> error "tPut1: empty result"
-
-tGet1 :: (ProtocolEncoding v err cmd, Transport c) => THandle v c 'TClient -> IO (Transmission (Either err cmd))
-tGet1 h = do
-  (r L.:| _) <- tGetClient h
-  pure r
-
-chunksOf :: Int -> [a] -> [[a]]
-chunksOf n = unfoldr $ \xs -> if null xs then Nothing else Just (splitAt n xs)
@@ -1,25 +0,0 @@
-FROM haskell:9.6.3 AS build
-
-WORKDIR /src
-
-# Copy cabal file first for dependency caching
-COPY simplexmq.cabal cabal.project* ./
-RUN cabal update && cabal build --only-dependencies -f server_postgres smp-server-bench || true
-
-# Copy full source
-COPY . .
-RUN cabal build -f server_postgres smp-server-bench \
-  && cp $(cabal list-bin -f server_postgres smp-server-bench) /usr/local/bin/smp-server-bench
-
-FROM debian:bookworm-slim
-
-RUN apt-get update && apt-get install -y --no-install-recommends \
-      libgmp10 libpq5 libffi8 zlib1g ca-certificates \
-  && rm -rf /var/lib/apt/lists/*
-
-COPY --from=build /usr/local/bin/smp-server-bench /usr/local/bin/smp-server-bench
-COPY tests/fixtures /app/tests/fixtures
-
-WORKDIR /app
-
-ENTRYPOINT ["smp-server-bench"]
@@ -1,243 +0,0 @@
-{-# LANGUAGE CPP #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE GADTs #-}
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE NumericUnderscores #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeApplications #-}
-{-# OPTIONS_GHC -fno-warn-ambiguous-fields #-}
-
-module Main where
-
-import Control.Concurrent (threadDelay)
-import Control.Concurrent.Async (async, cancel, forConcurrently_, mapConcurrently, mapConcurrently_)
-import Control.Concurrent.STM
-import Control.Monad (forever, forM_, void, when)
-import Data.ByteString.Char8 (ByteString)
-import qualified Data.ByteString.Char8 as B
-import Data.IORef
-import Data.List (unfoldr)
-import Data.Time.Clock (getCurrentTime, utctDayTime)
-import Network.Socket (ServiceName)
-import System.Environment (getArgs)
-import System.IO (hFlush, stdout)
-
-import ClientSim
-import Report
-
-import Crypto.Random (ChaChaDRG)
-import qualified Simplex.Messaging.Crypto as C
-import Simplex.Messaging.Server (runSMPServerBlocking)
-import Simplex.Messaging.Server.Env.STM as Env
-import Simplex.Messaging.Server.Expiration (ExpirationConfig (..))
-import Simplex.Messaging.Server.MsgStore.Postgres (PostgresMsgStore)
-import Simplex.Messaging.Server.QueueStore.Postgres.Config (PostgresStoreCfg (..))
-import Simplex.Messaging.Agent.Store.Postgres.Options (DBOpts (..))
-import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation (..))
-import Simplex.Messaging.Client.Agent (SMPClientAgentConfig (..), defaultSMPClientAgentConfig)
-import Simplex.Messaging.Transport
-import Simplex.Messaging.Transport.Server (ServerCredentials (..), mkTransportServerConfig)
-import Simplex.Messaging.Version
-import UnliftIO.Exception (bracket)
-
-import Control.Logger.Simple (logInfo, withGlobalLogging, LogConfig (..), setLogLevel, LogLevel (..))
-
-data BenchConfig = BenchConfig
-  { numClients :: Int,
-    sustainedMinutes :: Int,
-    pgConnStr :: ByteString,
-    serverPort :: ServiceName,
-    timeSeriesFile :: FilePath
-  }
-
-defaultBenchConfig :: BenchConfig
-defaultBenchConfig =
-  BenchConfig
-    { numClients = 5000,
-      sustainedMinutes = 5,
-      pgConnStr = "postgresql://smp@localhost:15432/smp_bench",
-      serverPort = "15001",
-      timeSeriesFile = "bench-timeseries.csv"
-    }
-
-parseArgs :: IO BenchConfig
-parseArgs = do
-  args <- getArgs
-  pure $ go args defaultBenchConfig
-  where
-    go [] c = c
-    go ("--clients" : n : rest) c = go rest c {numClients = read n}
-    go ("--minutes" : n : rest) c = go rest c {sustainedMinutes = read n}
-    go ("--pg" : s : rest) c = go rest c {pgConnStr = B.pack s}
-    go ("--port" : p : rest) c = go rest c {serverPort = p}
-    go ("--timeseries" : f : rest) c = go rest c {timeSeriesFile = f}
-    go (x : _) _ = error $ "Unknown argument: " <> x
-
-main :: IO ()
-main = withGlobalLogging LogConfig {lc_file = Nothing, lc_stderr = True} $ do
-  setLogLevel LogInfo
-  bc@BenchConfig {numClients, sustainedMinutes, serverPort, timeSeriesFile, pgConnStr} <- parseArgs
-  putStrLn $ "SMP Server Memory Benchmark"
-  putStrLn $ "  clients:  " <> show numClients
-  putStrLn $ "  sustain:  " <> show sustainedMinutes <> " min"
-  putStrLn $ "  pg:       " <> B.unpack pgConnStr
-  putStrLn $ "  port:     " <> serverPort
-  putStrLn ""
-
-  snapshotsRef <- newIORef []
-
-  let snap phase clients = do
-        s <- takeSnapshot phase clients
-        modifyIORef' snapshotsRef (s :)
-        putStrLn $ "  [" <> show phase <> "] live=" <> show (snapLive s `div` (1024 * 1024)) <> "MB large=" <> show (snapLarge s `div` (1024 * 1024)) <> "MB"
-        hFlush stdout
-
-  withBenchServer bc $ do
-    putStrLn "Phase 1: Baseline (no clients)"
-    snap "baseline" 0
-
-    putStrLn $ "Phase 2: Connecting " <> show numClients <> " TLS clients..."
-    handles <- connectN numClients "localhost" serverPort
-    putStrLn $ "  Connected " <> show (length handles) <> " clients"
-    snap "tls_connect" (length handles)
-
-    putStrLn "Phase 3: Creating queues (NEW + KEY)..."
-    simClients <- mapConcurrently createQueue handles
-    putStrLn $ "  Created " <> show (length simClients) <> " queues"
-    snap "queue_create" (length simClients)
-
-    putStrLn "Phase 4: Subscribing (SUB)..."
-    mapConcurrently_ subscribeQueue simClients
-    snap "subscribe" (length simClients)
-
-    -- Pair up clients: first half sends to second half
-    let halfN = length simClients `div` 2
-        senders = take halfN simClients
-        receivers = drop halfN simClients
-        pairs = zip senders receivers
-
-    putStrLn $ "Phase 5: Sending " <> show halfN <> " messages..."
-    g <- C.newRandom
-    forConcurrently_ pairs $ \(sender, receiver) -> do
-      (_, sKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g
-      sendMessage (scHandle sender) sKey (scSndId receiver) "benchmark test message payload 1234567890"
-    snap "msg_send" (length simClients)
-
-    putStrLn "Phase 6: Receiving and ACKing messages..."
-    forConcurrently_ receivers receiveAndAck
-    snap "msg_recv" (length simClients)
-
-    putStrLn $ "Phase 7: Sustained load (" <> show sustainedMinutes <> " min)..."
-    writeTimeSeriesHeader timeSeriesFile
-    -- Logger thread: snapshot every 10s
-    logger <- async $ forever $ do
-      threadDelay 10_000_000
-      s <- takeSnapshot "sustained" (length simClients)
-      appendTimeSeries timeSeriesFile s
-    -- Worker threads: continuous send/receive
-    let loopDurationUs = sustainedMinutes * 60 * 1_000_000
-    workersDone <- newTVarIO False
-    workers <- async $ do
-      deadline <- (+ loopDurationUs) <$> getMonotonicTimeUs
-      sustainedLoop g pairs deadline
-      atomically $ writeTVar workersDone True
-    -- Wait for workers
-    void $ atomically $ readTVar workersDone >>= \done -> when (not done) retry
-    cancel logger
-    cancel workers
-    snap "sustained_end" (length simClients)
-
-  snapshots <- reverse <$> readIORef snapshotsRef
-  printSummary snapshots
-  putStrLn $ "\nTime-series written to: " <> timeSeriesFile
-
-sustainedLoop :: TVar ChaChaDRG -> [(SimClient, SimClient)] -> Int -> IO ()
-sustainedLoop g pairs deadline = go
-  where
-    go = do
-      now <- getMonotonicTimeUs
-      when (now < deadline) $ do
-        forConcurrently_ pairs $ \(sender, receiver) -> do
-          (_, sKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g
-          sendMessage (scHandle sender) sKey (scSndId receiver) "sustained load message payload"
-        forConcurrently_ (map snd pairs) receiveAndAck
-        go
-
-getMonotonicTimeUs :: IO Int
-getMonotonicTimeUs = do
-  t <- getCurrentTime
-  pure $ round (utctDayTime t * 1_000_000)
-
-withBenchServer :: BenchConfig -> IO a -> IO a
-withBenchServer BenchConfig {pgConnStr, serverPort} action = do
-  started <- newEmptyTMVarIO
-  let srvCfg = benchServerConfig pgConnStr serverPort
-  bracket
-    (async $ runSMPServerBlocking started srvCfg Nothing)
-    cancel
-    (\_ -> waitForServer started >> action)
-  where
-    waitForServer started = do
-      r <- atomically $ takeTMVar started
-      if r
-        then putStrLn $ "Server started on port " <> serverPort
-        else error "Server failed to start"
-
-benchServerConfig :: ByteString -> ServiceName -> ServerConfig PostgresMsgStore
-benchServerConfig pgConn port =
-  let storeCfg = PostgresStoreCfg
-        { dbOpts = DBOpts {connstr = pgConn, schema = "smp_server", poolSize = 10, createSchema = True},
-          dbStoreLogPath = Nothing,
-          confirmMigrations = MCYesUp,
-          deletedTTL = 86400
-        }
-   in ServerConfig
-        { transports = [(port, transport @TLS, False)],
-          smpHandshakeTimeout = 120_000_000,
-          tbqSize = 128,
-          msgQueueQuota = 128,
-          maxJournalMsgCount = 256,
-          maxJournalStateLines = 16,
-          queueIdBytes = 24,
-          msgIdBytes = 24,
-          serverStoreCfg = SSCDatabase storeCfg,
-          storeNtfsFile = Nothing,
-          allowNewQueues = True,
-          newQueueBasicAuth = Nothing,
-          controlPortUserAuth = Nothing,
-          controlPortAdminAuth = Nothing,
-          dailyBlockQueueQuota = 20,
-          messageExpiration = Just defaultMessageExpiration,
-          expireMessagesOnStart = False,
-          expireMessagesOnSend = False,
-          idleQueueInterval = 14400,
-          notificationExpiration = defaultNtfExpiration,
-          inactiveClientExpiration = Nothing,
-          logStatsInterval = Nothing,
-          logStatsStartTime = 0,
-          serverStatsLogFile = "bench/tmp/stats.log",
-          serverStatsBackupFile = Nothing,
-          prometheusInterval = Nothing,
-          prometheusMetricsFile = "bench/tmp/metrics.txt",
-          pendingENDInterval = 500_000,
-          ntfDeliveryInterval = 200_000,
-          smpCredentials =
-            ServerCredentials
-              { caCertificateFile = Just "tests/fixtures/ca.crt",
-                privateKeyFile = "tests/fixtures/server.key",
-                certificateFile = "tests/fixtures/server.crt"
-              },
-          httpCredentials = Nothing,
-          smpServerVRange = supportedServerSMPRelayVRange,
-          Env.transportConfig = mkTransportServerConfig True (Just alpnSupportedSMPHandshakes) True,
-          controlPort = Nothing,
-          smpAgentCfg = defaultSMPClientAgentConfig {persistErrorInterval = 1},
-          allowSMPProxy = False,
-          serverClientConcurrency = 16,
-          information = Nothing,
-          startOptions = StartOptions {maintenance = False, compactLog = False, logLevel = LogInfo, skipWarnings = True, confirmMigrations = MCYesUp}
-        }
-
@@ -1,113 +0,0 @@
-{-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE NumericUnderscores #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-module Report
-  ( Snapshot (..),
-    takeSnapshot,
-    printSummary,
-    writeTimeSeriesHeader,
-    appendTimeSeries,
-  )
-where
-
-import Control.Concurrent (threadDelay)
-import Data.List (foldl')
-import Data.Text (Text)
-import qualified Data.Text as T
-import qualified Data.Text.IO as T
-import Data.Time.Clock (UTCTime, getCurrentTime)
-import Data.Time.Format.ISO8601 (iso8601Show)
-import Data.Word (Word32, Word64)
-import GHC.Stats (RTSStats (..), GCDetails (..), getRTSStats)
-import System.IO (Handle, IOMode (..), hFlush, hSetBuffering, BufferMode (..), withFile)
-import System.Mem (performMajorGC)
-
-data Snapshot = Snapshot
-  { snapTime :: UTCTime,
-    snapPhase :: Text,
-    snapLive :: Word64,
-    snapHeap :: Word64,
-    snapLarge :: Word64,
-    snapFrag :: Word64,
-    snapGCs :: Word32,
-    snapClients :: Int
-  }
-
-takeSnapshot :: Text -> Int -> IO Snapshot
-takeSnapshot phase clients = do
-  performMajorGC
-  threadDelay 1_000_000
-  rts <- getRTSStats
-  ts <- getCurrentTime
-  let GCDetails {gcdetails_live_bytes, gcdetails_mem_in_use_bytes, gcdetails_large_objects_bytes, gcdetails_block_fragmentation_bytes} = gc rts
-  pure
-    Snapshot
-      { snapTime = ts,
-        snapPhase = phase,
-        snapLive = gcdetails_live_bytes,
-        snapHeap = gcdetails_mem_in_use_bytes,
-        snapLarge = gcdetails_large_objects_bytes,
-        snapFrag = gcdetails_block_fragmentation_bytes,
-        snapGCs = gcs rts,
-        snapClients = clients
-      }
-
-printSummary :: [Snapshot] -> IO ()
-printSummary [] = putStrLn "No snapshots collected."
-printSummary snaps = do
-  putStrLn ""
-  putStrLn hdr
-  putStrLn $ replicate (length hdr) '-'
-  mapM_ printRow (zip (Snapshot {snapLive = 0, snapHeap = 0, snapLarge = 0, snapFrag = 0, snapGCs = 0, snapClients = 0, snapPhase = "", snapTime = snapTime (head snaps)} : snaps) snaps)
-  where
-    hdr = padR 20 "Phase" <> padL 12 "live_MB" <> padL 12 "large_MB" <> padL 12 "frag_MB" <> padL 12 "heap_MB" <> padL 10 "clients" <> padL 14 "d_live_MB" <> padL 14 "d_large_MB" <> padL 14 "KB/client"
-    printRow (prev, cur) =
-      putStrLn $
-        padR 20 (T.unpack $ snapPhase cur)
-          <> padL 12 (showMB $ snapLive cur)
-          <> padL 12 (showMB $ snapLarge cur)
-          <> padL 12 (showMB $ snapFrag cur)
-          <> padL 12 (showMB $ snapHeap cur)
-          <> padL 10 (show $ snapClients cur)
-          <> padL 14 (showDeltaMB (snapLive cur) (snapLive prev))
-          <> padL 14 (showDeltaMB (snapLarge cur) (snapLarge prev))
-          <> padL 14 (perClient cur)
-    showMB w = show (w `div` (1024 * 1024))
-    showDeltaMB a b
-      | a >= b = "+" <> show ((a - b) `div` (1024 * 1024))
-      | otherwise = "-" <> show ((b - a) `div` (1024 * 1024))
-    perClient Snapshot {snapClients, snapLive}
-      | snapClients > 0 = show (snapLive `div` fromIntegral snapClients `div` 1024)
-      | otherwise = "-"
-    padR n s = s <> replicate (max 0 (n - length s)) ' '
-    padL n s = replicate (max 0 (n - length s)) ' ' <> s
-
-csvHeader :: Text
-csvHeader = "timestamp,phase,rts_live,rts_heap,rts_large,rts_frag,rts_gc,clients"
-
-snapshotCsv :: Snapshot -> Text
-snapshotCsv Snapshot {snapTime, snapPhase, snapLive, snapHeap, snapLarge, snapFrag, snapGCs, snapClients} =
-  T.intercalate
-    ","
-    [ T.pack $ iso8601Show snapTime,
-      snapPhase,
-      tshow snapLive,
-      tshow snapHeap,
-      tshow snapLarge,
-      tshow snapFrag,
-      tshow snapGCs,
-      tshow snapClients
-    ]
-
-writeTimeSeriesHeader :: FilePath -> IO ()
-writeTimeSeriesHeader path = T.writeFile path (csvHeader <> "\n")
-
-appendTimeSeries :: FilePath -> Snapshot -> IO ()
-appendTimeSeries path snap =
-  withFile path AppendMode $ \h -> do
-    hSetBuffering h LineBuffering
-    T.hPutStrLn h $ snapshotCsv snap
-
-tshow :: Show a => a -> Text
-tshow = T.pack . show
@@ -1,46 +0,0 @@
-services:
-  postgres:
-    image: postgres:17
-    environment:
-      POSTGRES_USER: smp
-      POSTGRES_DB: smp_bench
-      POSTGRES_HOST_AUTH_METHOD: trust
-    volumes:
-      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
-      - pgdata:/var/lib/postgresql/data
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U smp -d smp_bench"]
-      interval: 2s
-      timeout: 5s
-      retries: 10
-
-  bench:
-    build:
-      context: ..
-      dockerfile: bench/Dockerfile
-    depends_on:
-      postgres:
-        condition: service_healthy
-    environment:
-      BENCH_PG: "postgresql://smp@postgres/smp_bench"
-      BENCH_CLIENTS: "${BENCH_CLIENTS:-5000}"
-      BENCH_MINUTES: "${BENCH_MINUTES:-5}"
-    command:
-      - "--pg"
-      - "postgresql://smp@postgres/smp_bench"
-      - "--clients"
-      - "${BENCH_CLIENTS:-5000}"
-      - "--minutes"
-      - "${BENCH_MINUTES:-5}"
-      - "--timeseries"
-      - "/results/timeseries.csv"
-      - "+RTS"
-      - "-N"
-      - "-A16m"
-      - "-T"
-      - "-RTS"
-    volumes:
-      - ./results:/results
-
-volumes:
-  pgdata:
@@ -1,2 +0,0 @@
-CREATE EXTENSION IF NOT EXISTS pgcrypto;
-CREATE SCHEMA IF NOT EXISTS smp_server;
@@ -1,60 +0,0 @@
-#!/bin/bash
-set -e
-cd "$(dirname "$0")"
-
-mkdir -p results
-
-reset_db() {
-  docker compose down -v 2>/dev/null || true
-  docker compose up -d --wait postgres
-  echo "PostgreSQL ready."
-}
-
-if [ "$1" = "--compare-rts" ]; then
-  shift
-  docker compose build bench
-  for label_flags in \
-    "default:-N -A16m -T" \
-    "F1.2:-N -A16m -F1.2 -T" \
-    "F1.5:-N -A16m -F1.5 -T" \
-    "A4m:-N -A4m -T" \
-    "A4m-F1.2:-N -A4m -F1.2 -T" \
-    "compact:-N -A16m -c -T" \
-    "nonmoving:-N -A16m -xn -T"; do
-    label="${label_flags%%:*}"
-    flags="${label_flags#*:}"
-    echo ""
-    echo "=========================================="
-    echo "  RTS config: $label ($flags)"
-    echo "=========================================="
-    reset_db
-    docker compose run --rm \
-      -e BENCH_CLIENTS="${BENCH_CLIENTS:-1000}" \
-      -e BENCH_MINUTES="${BENCH_MINUTES:-2}" \
-      bench \
-      --pg "postgresql://smp@postgres/smp_bench" \
-      --clients "${BENCH_CLIENTS:-1000}" \
-      --minutes "${BENCH_MINUTES:-2}" \
-      --timeseries "/results/bench-${label}.csv" \
-      "$@" \
-      +RTS $flags -RTS
-  done
-  echo ""
-  echo "Done. Results in bench/results/"
-elif [ "$1" = "--local" ]; then
-  # Run natively (not in container) — requires local Postgres
-  shift
-  reset_db
-  cabal run smp-server-bench -f server_postgres -- \
-    --pg "postgresql://smp@localhost:15432/smp_bench" \
-    --clients "${BENCH_CLIENTS:-5000}" \
-    --minutes "${BENCH_MINUTES:-5}" \
-    "$@" \
-    +RTS -N -A16m -s -RTS
-else
-  # Run fully in containers
-  reset_db
-  docker compose run --rm bench "$@"
-fi
-
-docker compose down
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: Apache-2.0
+// getentropy() shim for Windows, where it is absent from the CRT.
+// Follows the POSIX contract: fills `buffer` with `length` random bytes
+// (length must not exceed 256), returns 0 on success or -1 with errno set.
+#ifdef _WIN32
+#include <errno.h>
+#include <stddef.h>
+#include <windows.h>
+#include <bcrypt.h>
+
+int getentropy(void *buffer, size_t length) {
+    if (length > 256) {
+        errno = EIO;
+        return -1;
+    }
+    NTSTATUS status = BCryptGenRandom(NULL, (PUCHAR)buffer, (ULONG)length,
+                                      BCRYPT_USE_SYSTEM_PREFERRED_RNG);
+    if (!BCRYPT_SUCCESS(status)) {
+        errno = EIO;
+        return -1;
+    }
+    return 0;
+}
+#endif
@@ -1,100 +0,0 @@
-## Memory Diagnostics Results
-
-### Data Collection
-
-Server: smp19.simplex.im, PostgreSQL backend, `useCache = False`
-RTS flags: `+RTS -N -A16m -I0.01 -Iw15 -s -RTS` (16 cores)
-
-### Mar 20 Data (1 hour, 07:19-08:19)
-
-```
-Time    rts_live  rts_heap  rts_large  rts_frag   clients  non-large
-07:19    7.5 GB    8.2 GB    5.5 GB    0.03 GB    14,000    2.0 GB
-07:24    6.4 GB   10.8 GB    5.2 GB    3.6 GB     14,806    1.2 GB
-07:29    8.2 GB   10.8 GB    6.5 GB    1.8 GB     15,667    1.7 GB
-07:34   10.0 GB   12.3 GB    7.9 GB    1.4 GB     15,845    2.1 GB
-07:39    6.7 GB   13.0 GB    5.3 GB    5.6 GB     16,589    1.4 GB
-07:44    8.5 GB   13.0 GB    6.7 GB    3.7 GB     16,283    1.8 GB
-07:49    6.5 GB   13.0 GB    5.2 GB    5.8 GB     16,532    1.3 GB
-07:54    6.0 GB   13.0 GB    4.8 GB    6.3 GB     16,636    1.2 GB
-07:59    6.4 GB   13.0 GB    5.1 GB    5.9 GB     16,769    1.3 GB
-08:04    8.3 GB   13.0 GB    6.5 GB    3.9 GB     17,352    1.8 GB
-08:09   10.2 GB   13.0 GB    8.0 GB    1.9 GB     17,053    2.2 GB
-08:14    5.6 GB   13.0 GB    4.5 GB    6.8 GB     17,147    1.1 GB
-08:19    7.6 GB   13.0 GB    6.1 GB    4.6 GB     17,496    1.5 GB
-```
-
-non-large = rts_live - rts_large (normal Haskell heap objects: Maps, TVars, closures)
-
-### Mar 19 Data (5.5 hours, 07:49-13:19)
-
-rts_heap grew from 10.1 GB to 20.7 GB over 5.5 hours.
-Post-GC rts_live floor rose from 5.5 GB to 9.1 GB.
-
-### Findings
-
-**1. Large/pinned objects dominate live data (60-80%)**
-
-`rts_large` = 4.5-8.0 GB out of 5.6-10.2 GB live. These are allocations > ~3KB that go on GHC's large object heap. They oscillate (not growing monotonically), meaning they are being allocated and freed constantly — transient, not leaked.
-
-**2. Fragmentation is the heap growth mechanism**
-
-`rts_heap ≈ rts_live + rts_frag`. The heap grows because pinned/large objects fragment GHC's block allocator. Once GHC expands the heap, it never shrinks. Growth pattern:
- Large objects allocated → occupy blocks
- Large objects freed → blocks can't be reused if ANY other object shares the block
- New allocations need fresh blocks → heap expands
- Heap never returns memory to OS
-
-**3. Non-large heap data is stable (~1.0-2.2 GB)**
-
-Normal Haskell objects (Maps, TVars, closures, client structures) account for only 1-2 GB. This scales with client count at ~100-130 KB/client and does NOT grow over time.
-
-**4. All tracked data structures are NOT the cause**
-
- `clientSndQ=0, clientMsgQ=0` — TBQueues empty, no message accumulation
- `smpQSubs` oscillates ~1.0-1.4M — entries are cleaned up, not leaking
- `ntfStore` < 2K entries — negligible
- All proxy agent maps near 0
- `loadedQ=0` — useCache=False confirmed working
-
-**5. Source of large objects is unclear without heap profiling**
-
-The 4.5-8.0 GB of large objects could come from:
- PostgreSQL driver (`postgresql-simple`/`libpq`) — pinned ByteStrings for query results
- TLS library (`tls`) — pinned buffers per connection
- Network socket I/O — pinned ByteStrings for recv/send
- SMP protocol message blocks
-
-Cannot distinguish between these without `-hT` heap profiling (which is too expensive for this server).
-
-### Root Cause
-
-**GHC heap fragmentation from constant churn of large/pinned ByteString allocations.**
-
-Not a data structure leak. The live data itself is reasonable (5-10 GB for 15-17K clients). The problem is that GHC's copying GC cannot compact around pinned objects, so the heap grows with fragmentation and never shrinks.
-
-### Mitigation Options
-
-All are RTS flag changes — no rebuild needed, reversible by restart.
-
-**1. `-F1.2`** (reduce GC trigger factor from default 2.0)
- Triggers major GC when heap reaches 1.2x live data instead of 2x
- Reclaims fragmented blocks sooner
- Trade-off: more frequent GC, slightly higher CPU
- Risk: low — just makes GC run more often
-
-**2. Reduce `-A16m` to `-A4m`** (smaller nursery)
- More frequent minor GC → short-lived pinned objects freed faster
- Trade-off: more GC cycles, but each is smaller
- Risk: low — may actually improve latency by reducing GC pause times
-
-**3. `+RTS -xn`** (nonmoving GC)
- Designed for pinned-heavy workloads — avoids copying entirely
- Available since GHC 8.10, improved in 9.x
- Trade-off: different GC characteristics, less battle-tested
- Risk: medium — different GC algorithm, should test first
-
-**4. Limit concurrent connections** (application-level)
- Since large objects scale per-client, fewer clients = less fragmentation
- Trade-off: reduced capacity
- Risk: low but impacts users
@@ -1,225 +0,0 @@
-## Root Cause Analysis: SMP Server Memory Growth (23.5GB)
-
-### Environment
-
- **Server**: smp19.simplex.im, ~21,927 connected clients
- **Storage**: PostgreSQL backend with `useCache = False`
- **RTS flags**: `+RTS -N -A16m -I0.01 -Iw15 -s -RTS` (16 cores)
- **Memory**: 23.5GB RES / 1031GB VIRT (75% of available RAM)
-
-### Log Summary
-
- **Duration**: ~22 hours (Mar 16 12:12 → Mar 17 10:20)
- **92,277 proxy connection errors** out of 92,656 total log lines (99.6%)
- **292 unique failing destination servers**, top offender: `nowhere.moe` (12,875 errors)
- Only **145 successful proxy connections**
-
---
-
-### Known Factor: GHC Heap Sizing
-
-With 16 cores and `-A16m`:
- **Nursery**: 16 × 16MB = **256MB baseline**
- GHC default major GC threshold = **2× live data** — if live data is 10GB, heap grows to ~20GB before major GC
- The server is rarely idle with 22K clients, so major GC is deferred despite `-I0.01`
- This is an amplifier — whatever the actual live data size is, GHC roughly doubles it
-
---
-
-### Candidate Structures That Could Grow Unboundedly
-
-Analysis of the full codebase identified these structures that either grow without bound or have uncertain cleanup:
-
-#### 1. `SubscribedClients` maps — `Env/STM.hs:378`
-
-Both `subscribers.queueSubscribers` and `ntfSubscribers.queueSubscribers` (and their `serviceSubscribers`) use `SubscribedClients (TMap EntityId (TVar (Maybe (Client s))))`.
-
-Comment at line 376: *"The subscriptions that were made at any point are not removed"*
-
-`deleteSubcribedClient` IS called on disconnect (Server.hs:1112) and DOES call `TM.delete`. But it only deletes if the current stored client matches — if another client already re-subscribed, the old client's disconnect won't remove the entry. This is by design for mobile client continuity, but the net effect on map size over time is unclear without measurement.
-
-#### 2. ProxyAgent's subscription TMaps — `Client/Agent.hs:145-151`
-
-The `SMPClientAgent` has 4 TMaps that accumulate one top-level entry per unique destination server and **never remove** them:
-
- `activeServiceSubs :: TMap SMPServer (TVar ...)` (line 145)
- `activeQueueSubs :: TMap SMPServer (TMap QueueId ...)` (line 146)
- `pendingServiceSubs :: TMap SMPServer (TVar ...)` (line 149)
- `pendingQueueSubs :: TMap SMPServer (TMap QueueId ...)` (line 150)
-
-Comment at line 262: *"these vars are never removed, they are only added"*
-
-These are only used for the proxy agent (SParty 'Sender), so they grow with each unique destination SMP server proxied to. With 292 unique servers in this log period, these are likely small — but long-running servers may accumulate thousands.
-
-`closeSMPClientAgent` (line 369) does NOT clear these 4 maps.
-
-#### 3. `NtfStore` — `NtfStore.hs:26`
-
-`NtfStore (TMap NotifierId (TVar [MsgNtf]))` — one entry per NotifierId.
-
-`deleteExpiredNtfs` (line 47) filters expired notifications from lists but does **not remove entries with empty lists** from the TMap. Over time, NotifierIds that no longer receive notifications leave zombie `TVar []` entries.
-
-`deleteNtfs` (line 44) does remove the full entry via `TM.lookupDelete` — but only called when a notifier is explicitly deleted.
-
-#### 4. `serviceLocks` in PostgresQueueStore — `Postgres.hs:112,469`
-
-`serviceLocks :: TMap CertFingerprint Lock` — one Lock per unique certificate fingerprint.
-
-`getCreateService` (line 469) calls `withLockMap (serviceLocks st) fp` which calls `getMapLock` (Agent/Client.hs:1029-1032) — this **unconditionally inserts** a Lock into the TMap. There is **no cleanup code** for serviceLocks anywhere. This is NOT guarded by `useCache`.
-
-#### 5. `sentCommands` per proxy client connection — `Client.hs:580`
-
-Each `PClient` has `sentCommands :: TMap CorrId (Request err msg)`. Entries are added per command sent (line 1369) and only removed when a response arrives (line 698). If a connection drops before all responses arrive, entries remain until the `PClient` is GC'd. Since `PClient` is captured by the connection thread which terminates on error, the `PClient` should become GC-eligible — but GC timing depends on heap pressure.
-
-#### 6. `subQ :: TQueue (ClientSub, ClientId)` — `Env/STM.hs:363`
-
-Unbounded `TQueue` for subscription changes. If the subscriber thread (`serverThread`) can't process changes fast enough, this queue grows without backpressure. With 22K clients subscribing/unsubscribing, sustained bursts could cause this queue to bloat.
-
---
-
-### Ruled Out
-
-1. **PostgreSQL queue cache**: `useCache = False` — `queues`, `senders`, `links`, `notifiers` TMaps are empty.
-2. **`notifierLocks`**: Guarded by `useCache` (Postgres.hs:377,405) — not used with `useCache = False`.
-3. **Client structures**: 22K × ~3KB = ~66MB — negligible.
-4. **TBQueues**: Bounded (`tbqSize = 128`).
-5. **Thread management**: `forkClient` uses weak refs + `finally` blocks. `endThreads` cleared on disconnect.
-6. **Proxy `smpClients`/`smpSessions`**: Properly cleaned on disconnect/expiry.
-7. **`smpSubWorkers`**: Properly cleaned on worker completion; also cleared in `closeSMPClientAgent`.
-8. **`pendingEvents`**: Atomically swapped empty every `pendingENDInterval`.
-9. **Stats IORef counters**: Fixed number, bounded.
-10. **DB connection pool**: Bounded `TBQueue` with bracket-based return.
-
---
-
-### Insufficient Data to Determine Root Cause
-
-Without measuring the actual sizes of these structures at runtime, we cannot determine which (if any) is the primary contributor. The following exact logging changes will identify the root cause.
-
---
-
-### EXACT LOGS TO ADD
-
-Add a new periodic logging thread in `src/Simplex/Messaging/Server.hs`.
-
-Insert at `Server.hs:197` (after `prometheusMetricsThread_`):
-
-```haskell
-        <> memoryDiagThread_ cfg
-```
-
-Then define:
-
-```haskell
-    memoryDiagThread_ :: ServerConfig s -> [M s ()]
-    memoryDiagThread_ ServerConfig {prometheusInterval = Just _} =
-      [memoryDiagThread]
-    memoryDiagThread_ _ = []
-
-    memoryDiagThread :: M s ()
-    memoryDiagThread = do
-      labelMyThread "memoryDiag"
-      Env { ntfStore = NtfStore ntfMap
-          , server = srv@Server {subscribers, ntfSubscribers}
-          , proxyAgent = ProxyAgent {smpAgent = pa}
-          , msgStore_ = ms
-          } <- ask
-      let interval = 300_000_000 -- 5 minutes
-      liftIO $ forever $ do
-        threadDelay interval
-        -- GHC RTS stats
-        rts <- getRTSStats
-        let liveBytes = gcdetails_live_bytes $ gc rts
-            heapSize = gcdetails_mem_in_use_bytes $ gc rts
-            gcCount = gcs rts
-        -- Server structures
-        clientCount <- IM.size <$> getServerClients srv
-        -- SubscribedClients (queue and service subscribers for both SMP and NTF)
-        smpQSubs <- M.size <$> getSubscribedClients (queueSubscribers subscribers)
-        smpSSubs <- M.size <$> getSubscribedClients (serviceSubscribers subscribers)
-        ntfQSubs <- M.size <$> getSubscribedClients (queueSubscribers ntfSubscribers)
-        ntfSSubs <- M.size <$> getSubscribedClients (serviceSubscribers ntfSubscribers)
-        -- Pending events
-        smpPending <- IM.size <$> readTVarIO (pendingEvents subscribers)
-        ntfPending <- IM.size <$> readTVarIO (pendingEvents ntfSubscribers)
-        -- NtfStore
-        ntfStoreSize <- M.size <$> readTVarIO ntfMap
-        -- ProxyAgent maps
-        let SMPClientAgent {smpClients, smpSessions, activeServiceSubs, activeQueueSubs, pendingServiceSubs, pendingQueueSubs, smpSubWorkers} = pa
-        paClients <- M.size <$> readTVarIO smpClients
-        paSessions <- M.size <$> readTVarIO smpSessions
-        paActSvc <- M.size <$> readTVarIO activeServiceSubs
-        paActQ <- M.size <$> readTVarIO activeQueueSubs
-        paPndSvc <- M.size <$> readTVarIO pendingServiceSubs
-        paPndQ <- M.size <$> readTVarIO pendingQueueSubs
-        paWorkers <- M.size <$> readTVarIO smpSubWorkers
-        -- Loaded queue counts
-        lc <- loadedQueueCounts $ fromMsgStore ms
-        -- Log everything
-        logInfo $
-          "MEMORY "
-            <> "rts_live=" <> tshow liveBytes
-            <> " rts_heap=" <> tshow heapSize
-            <> " rts_gc=" <> tshow gcCount
-            <> " clients=" <> tshow clientCount
-            <> " smpQSubs=" <> tshow smpQSubs
-            <> " smpSSubs=" <> tshow smpSSubs
-            <> " ntfQSubs=" <> tshow ntfQSubs
-            <> " ntfSSubs=" <> tshow ntfSSubs
-            <> " smpPending=" <> tshow smpPending
-            <> " ntfPending=" <> tshow ntfPending
-            <> " ntfStore=" <> tshow ntfStoreSize
-            <> " paClients=" <> tshow paClients
-            <> " paSessions=" <> tshow paSessions
-            <> " paActSvc=" <> tshow paActSvc
-            <> " paActQ=" <> tshow paActQ
-            <> " paPndSvc=" <> tshow paPndSvc
-            <> " paPndQ=" <> tshow paPndQ
-            <> " paWorkers=" <> tshow paWorkers
-            <> " loadedQ=" <> tshow (loadedQueueCount lc)
-            <> " loadedNtf=" <> tshow (loadedNotifierCount lc)
-            <> " ntfLocks=" <> tshow (notifierLockCount lc)
-```
-
-Note: `smpSubs.subsCount` (queueSubscribers size) and `smpSubs.subServicesCount` (serviceSubscribers size) are **already logged** in Prometheus (lines 475-496). The log above adds all other candidate structures plus GHC RTS memory stats.
-
-This produces a single log line every 5 minutes:
-
-```
-[INFO] MEMORY rts_live=10737418240 rts_heap=23488102400 rts_gc=4521 clients=21927 smpQSubs=1847233 smpSSubs=42 ntfQSubs=982112 ntfSSubs=31 smpPending=0 ntfPending=0 ntfStore=512844 paClients=12 paSessions=12 paActSvc=0 paActQ=0 paPndSvc=0 paPndQ=0 paWorkers=3 loadedQ=0 loadedNtf=0 ntfLocks=0
-```
-
-### What Each Metric Tells Us
-
-| Metric | What it reveals | If growing = suspect |
-|--------|----------------|---------------------|
-| `rts_live` | Actual live data after last major GC | Baseline — everything else should add up to this |
-| `rts_heap` | Total heap (should be ~2× rts_live) | If >> 2× live, fragmentation issue |
-| `clients` | Connected client count | Known: ~22K |
-| `smpQSubs` | SubscribedClients map size (queue subs) | If >> clients × avg_subs, entries not cleaned |
-| `smpSSubs` | SubscribedClients map size (service subs) | Should be small |
-| `ntfQSubs` | NTF SubscribedClients map (queue subs) | Same concern as smpQSubs |
-| `ntfSSubs` | NTF SubscribedClients map (service subs) | Should be small |
-| `smpPending` / `ntfPending` | Pending END/DELD events per client | If large, subscriber thread lagging |
-| `ntfStore` | NotifierId count in NtfStore | If growing monotonically, zombie entries |
-| `paClients` | Proxy connections to other servers | Should be <= unique dest servers |
-| `paSessions` | Active proxy sessions | Should match paClients |
-| `paActSvc` / `paActQ` | Proxy active subscriptions | If growing, entries never removed |
-| `paPndSvc` / `paPndQ` | Proxy pending subscriptions | If growing, resubscription stuck |
-| `paWorkers` | Active reconnect workers | If growing, workers stuck in retry |
-| `loadedQ` | Cached queues in store (0 with useCache=False) | Should be 0 |
-| `ntfLocks` | Notifier locks in store | Should be 0 with useCache=False |
-
-### Interpretation Guide
-
-**If `smpQSubs` is in the millions**: SubscribedClients is the primary leak. Entries accumulate for every queue ever subscribed to.
-
-**If `ntfStore` grows monotonically**: Zombie notification entries (empty lists after expiration). Fix: `deleteExpiredNtfs` should remove entries with empty lists.
-
-**If `paActSvc` + `paActQ` grow**: Proxy agent subscription maps are the leak. Fix: add cleanup when no active/pending subs exist for a server.
-
-**If `rts_live` is much smaller than `rts_heap`**: GHC heap fragmentation. Fix: tune `-F` flag (GC trigger factor) or use `-c` (compacting GC).
-
-**If `rts_live` ~ 10-12GB**: The live data is genuinely large. Look at which metric is the largest contributor.
-
-**If nothing above is large but `rts_live` is large**: The leak is in a structure not measured here — likely TLS connection buffers, ByteString retention from Postgres queries, or GHC runtime overhead. Next step would be heap profiling with `-hT`.
@@ -0,0 +1,472 @@
+# XFTP Server PostgreSQL Backend
+
+## Overview
+
+Add PostgreSQL backend support to xftp-server, following the SMP server pattern. Supports bidirectional migration between STM (in-memory with StoreLog) and PostgreSQL backends.
+
+## Goals
+
+- PostgreSQL-backed file metadata storage as an alternative to STM + StoreLog
+- Polymorphic server code via `FileStoreClass` typeclass with IO-based methods (following `QueueStoreClass` pattern)
+- Bidirectional migration: StoreLog <-> PostgreSQL via CLI commands
+- Shared `server_postgres` cabal flag (same flag enables both SMP and XFTP Postgres support)
+- INI-based backend selection at runtime
+
+## Architecture
+
+### FileStoreClass Typeclass
+
+IO-based typeclass following the `QueueStoreClass` pattern — each method is a self-contained IO action, with the implementation responsible for its own atomicity (STM backend wraps in `atomically`, Postgres backend uses database transactions):
+
+```haskell
+class FileStoreClass s where
+  type FileStoreConfig s
+
+  -- Lifecycle
+  newFileStore :: FileStoreConfig s -> IO s
+  closeFileStore :: s -> IO ()
+
+  -- File operations
+  addFile :: s -> SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> IO (Either XFTPErrorType ())
+  setFilePath :: s -> SenderId -> FilePath -> IO (Either XFTPErrorType ())
+  addRecipient :: s -> SenderId -> FileRecipient -> IO (Either XFTPErrorType ())
+  getFile :: s -> SFileParty p -> XFTPFileId -> IO (Either XFTPErrorType (FileRec, C.APublicAuthKey))
+  deleteFile :: s -> SenderId -> IO (Either XFTPErrorType ())
+  blockFile :: s -> SenderId -> BlockingInfo -> Bool -> IO (Either XFTPErrorType ())
+  deleteRecipient :: s -> RecipientId -> FileRec -> IO ()
+  ackFile :: s -> RecipientId -> IO (Either XFTPErrorType ())
+
+  -- Expiration (with LIMIT for Postgres; called in a loop until empty)
+  expiredFiles :: s -> Int64 -> Int -> IO [(SenderId, Maybe FilePath, Word32)]
+
+  -- Storage and stats (for init-time computation)
+  getUsedStorage :: s -> IO Int64
+  getFileCount :: s -> IO Int
+```
+
+- STM backend: each method wraps its STM transaction in `atomically` internally.
+- Postgres backend: each method runs its query via `withDB` / database connection internally.
+
+No polymorphic monad or `runStore` dispatcher needed — unlike `MsgStoreClass`, XFTP file operations are individually atomic and don't require grouping multiple operations into backend-dependent transactions.
+
+### PostgresFileStore Data Type
+
+```haskell
+data PostgresFileStore = PostgresFileStore
+  { dbStore :: DBStore,
+    dbStoreLog :: Maybe (StoreLog 'WriteMode)
+  }
+```
+
+- `dbStore` — connection pool created via `createDBStore`, runs schema migrations on init.
+- `dbStoreLog` — optional parallel log file (enabled by `db_store_log` INI setting). When present, every mutation (`addFile`, `setFilePath`, `deleteFile`, `blockFile`, `addRecipient`, `ackFile`) also writes to this log via a `withLog` wrapper. `withLog` is called AFTER the DB operation succeeds (so the log reflects committed state only). Log write failures are non-fatal (logged as warnings, do not fail the DB operation). This provides an audit trail and enables recovery via export.
+
+`closeFileStore` for Postgres calls `closeDBStore` (closes connection pool) then `mapM_ closeStoreLog dbStoreLog` (flushes and closes the parallel log). For STM, it closes the storeLog. Called from a `finally` block during server shutdown, matching SMP's `stopServer` → `closeMsgStore` → `closeQueueStore` pattern.
+
+### STMFileStore Type
+
+After extracting from current `Store.hs`, `STMFileStore` retains the file and recipient maps but no longer owns `usedStorage` (moved to `XFTPEnv`):
+
+```haskell
+data STMFileStore = STMFileStore
+  { files :: TMap SenderId FileRec,
+    recipients :: TMap RecipientId (SenderId, RcvPublicAuthKey)
+  }
+```
+
+`closeFileStore` for STM is a no-op (TMaps are garbage-collected; the env-level `storeLog` is closed separately by the server).
+
+### Error Handling
+
+Postgres operations follow SMP's `withDB` / `handleDuplicate` pattern:
+
+```haskell
+withDB :: Text -> PostgresFileStore -> (DB.Connection -> IO (Either XFTPErrorType a)) -> ExceptT XFTPErrorType IO a
+withDB op st action =
+  ExceptT $ E.try (withTransaction (dbStore st) action) >>= either logErr pure
+  where
+    logErr :: E.SomeException -> IO (Either XFTPErrorType a)
+    logErr e = logError ("STORE: " <> err) $> Left INTERNAL
+      where
+        err = op <> ", withDB, " <> tshow e
+
+handleDuplicate :: SqlError -> IO (Either XFTPErrorType a)
+handleDuplicate e = case constraintViolation e of
+  Just (UniqueViolation _) -> pure $ Left DUPLICATE_
+  _ -> E.throwIO e
+```
+
+- All DB operations wrapped in `withDB` — catches exceptions, logs, returns `INTERNAL`.
+- Unique constraint violations caught by `handleDuplicate` and mapped to `DUPLICATE_`.
+- UPDATE operations verified with `assertUpdated` — returns `AUTH` if 0 rows affected (matching SMP pattern, prevents silent failures when WHERE clause doesn't match).
+- Critical sections (DB write + TVar update) wrapped in `uninterruptibleMask_` to prevent async exceptions from leaving inconsistent state between DB and TVars.
+
+### FileRec and TVar Fields
+
+`FileRec` retains its `TVar` fields (matching SMP's `PostgresQueue` pattern):
+
+```haskell
+data FileRec = FileRec
+  { senderId :: SenderId,
+    fileInfo :: FileInfo,
+    filePath :: TVar (Maybe FilePath),
+    recipientIds :: TVar (Set RecipientId),
+    createdAt :: RoundedFileTime,
+    fileStatus :: TVar ServerEntityStatus
+  }
+```
+
+- **STM backend**: TVars are the source of truth, as currently.
+- **Postgres backend**: `getFile` reads from DB and creates a `FileRec` with fresh TVars populated from the DB row (matching SMP's `mkQ` pattern — `newTVarIO` per load). Mutation methods (`setFilePath`, `blockFile`, etc.) update both the DB (persistence) and the TVars (in-session consistency). The `recipientIds` TVar is initialized to `S.empty` — no subquery needed because no server code reads `recipientIds` directly; all recipient operations go through the typeclass methods (`addRecipient`, `deleteRecipient`, `ackFile`), which query the `recipients` table for Postgres.
+
+### usedStorage Ownership
+
+`usedStorage :: TVar Int64` moves from the store to `XFTPEnv`. The store typeclass does **not** manage `usedStorage` — it only provides `getUsedStorage` for init-time computation.
+
+- **STM init**: StoreLog replay calls `setFilePath` (which only sets the filePath TVar — the STM `setFilePath` implementation is changed to **not** update `usedStorage`). Similarly, STM `deleteFile` (Store.hs line 117) and `blockFile` (line 125) are changed to **not** update `usedStorage` — the server handles all `usedStorage` adjustments externally. After replay, `getUsedStorage` computes the sum over all file sizes (matching current `countUsedStorage` behavior).
+- **Postgres init**: `getUsedStorage` executes `SELECT COALESCE(SUM(file_size), 0) FROM files`.
+- **Runtime**: Server manages `usedStorage` TVar directly for reserve/commit/rollback during uploads, and adjusts after `deleteFile`/`blockFile` calls.
+
+**Note on `getUsedStorage` semantics**: The current STM `countUsedStorage` sums all file sizes unconditionally (including files without `filePath` set, i.e., created but not yet uploaded). The Postgres `getUsedStorage` matches this: `SELECT SUM(file_size) FROM files` (no `WHERE file_path IS NOT NULL`). In practice, orphaned files (created but never uploaded) are rare and short-lived (expired within 48h), so the difference is negligible. A future improvement could filter by `file_path IS NOT NULL` in both backends to reflect actual disk usage more accurately.
+
+### Server.hs Refactoring
+
+`Server.hs` becomes polymorphic over `FileStoreClass s`. Since all typeclass methods are IO, call sites replace `atomically` with direct IO calls to the store.
+
+**Call sites requiring changes** (exhaustive list):
+
+1. **`receiveServerFile`** (line 563): `atomically $ writeTVar filePath (Just fPath)` → `setFilePath store senderId fPath`. The `reserve` logic (line 551-555) stays as direct TVar manipulation on `usedStorage` from `XFTPEnv`.
+
+2. **`verifyXFTPTransmission`** (line 453): `atomically $ verify =<< getFile st party fId` — the `getFile` call and subsequent `readTVar fileStatus` are in a single `atomically` block. Refactored to: `getFile st party fId` (IO), then `readTVarIO (fileStatus fr)` from the returned `FileRec` (safe for both backends — STM TVar is the source of truth, Postgres TVar is a fresh snapshot from DB).
+
+3. **`retryAdd`** (line 516): Signature `XFTPFileId -> STM (Either XFTPErrorType a)` → `XFTPFileId -> IO (Either XFTPErrorType a)`. The `atomically` call (line 520) replaced with `liftIO`.
+
+4. **`deleteOrBlockServerFile_`** (line 620): Parameter `FileStore -> STM (Either XFTPErrorType ())` → `FileStoreClass s => s -> IO (Either XFTPErrorType ())`. The `atomically` call (line 626) removed — the store method is already IO. After the store action, server adjusts `usedStorage` TVar in `XFTPEnv` based on `fileInfo.size`.
+
+5. **`ackFileReception`** (line 605): `atomically $ deleteRecipient st rId fr` → `deleteRecipient st rId fr`.
+
+6. **Control port `CPDelete`/`CPBlock`** (lines 371, 377): `atomically $ getFile fs SFRecipient fileId` → `getFile fs SFRecipient fileId`.
+
+7. **`expireServerFiles`** (line 636): Replace per-file `expiredFilePath` iteration with batched `expiredFiles st old batchSize`, which returns `[(SenderId, Maybe FilePath, Word32)]` — the `Word32` file size is needed so the server can adjust the `usedStorage` TVar after each deletion. Called in a loop until the returned list is empty. The `itemDelay` between files applies to the deletion loop over each batch, not the query itself. STM backend ignores the batch size limit (returns all expired files from TMap scan); Postgres uses `LIMIT`.
+
+8. **`restoreServerStats`** (line 694): `FileStore {files, usedStorage} <- asks store` accesses store fields directly. Refactored to: `usedStorage` from `XFTPEnv` via `asks usedStorage`, file count via `getFileCount store`. STM: `M.size <$> readTVarIO files`. Postgres: `SELECT COUNT(*) FROM files`.
+
+### Store Config Selection
+
+GADT in `Env.hs`:
+
+```haskell
+data XFTPStoreConfig s where
+  XSCMemory :: Maybe FilePath -> XFTPStoreConfig STMFileStore
+#if defined(dbServerPostgres)
+  XSCDatabase :: PostgresFileStoreCfg -> XFTPStoreConfig PostgresFileStore
+#endif
+```
+
+`XFTPEnv` becomes polymorphic:
+
+```haskell
+data XFTPEnv s = XFTPEnv
+  { config :: XFTPServerConfig,
+    store :: s,
+    usedStorage :: TVar Int64,
+    storeLog :: Maybe (StoreLog 'WriteMode),
+    ...
+  }
+```
+
+The `M` monad (`ReaderT (XFTPEnv s) IO`) and all functions in `Server.hs` gain `FileStoreClass s =>` constraints.
+
+**StoreLog lifecycle per backend:**
+
+- **STM mode**: `storeLog = Just sl` (current behavior — append-only log for persistence and recovery).
+- **Postgres mode**: `storeLog = Nothing` (main storeLog disabled — Postgres is the source of truth). The optional parallel `dbStoreLog` inside `PostgresFileStore` provides audit/recovery if enabled via `db_store_log` INI setting.
+
+The existing `withFileLog` pattern in Server.hs continues to work unchanged — it maps over `Maybe (StoreLog 'WriteMode)`, which is `Nothing` in Postgres mode so the calls become no-ops.
+
+### Main.hs Store Type Dispatch
+
+The `Start` CLI command gains a `--confirm-migrations` flag (default `MCConsole` — manual prompt, matching SMP's `StartOptions`). For automated deployments, `--confirm-migrations up` auto-applies forward migrations. The import command uses `MCYesUp` (always auto-apply).
+
+Following SMP's existential dispatch pattern (`AStoreType` + `run`), `Main.hs` selects the store type from INI config and dispatches to the polymorphic server:
+
+```haskell
+runServer ini = do
+  let storeType = fromRight "memory" $ lookupValue "STORE_LOG" "store_files" ini
+  case storeType of
+    "memory" -> run $ XSCMemory (enableStoreLog $> storeLogFilePath)
+    "database" ->
+#if defined(dbServerPostgres)
+      run $ XSCDatabase PostgresFileStoreCfg {..}
+#else
+      exitError "server not compiled with Postgres support"
+#endif
+    _ -> exitError $ "Invalid store_files value: " <> storeType
+  where
+    run :: FileStoreClass s => XFTPStoreConfig s -> IO ()
+    run storeCfg = do
+      env <- newXFTPServerEnv storeCfg config
+      runReaderT (xftpServer config) env
+```
+
+**`newXFTPServerEnv` refactored signature:**
+
+```haskell
+newXFTPServerEnv :: FileStoreClass s => XFTPStoreConfig s -> XFTPServerConfig -> IO (XFTPEnv s)
+newXFTPServerEnv storeCfg config = do
+  (store, storeLog) <- case storeCfg of
+    XSCMemory storeLogPath -> do
+      st <- newFileStore ()
+      sl <- mapM (`readWriteFileStore` st) storeLogPath
+      pure (st, sl)
+    XSCDatabase dbCfg -> do
+      st <- newFileStore dbCfg
+      pure (st, Nothing)  -- main storeLog disabled for Postgres
+  usedStorage <- newTVarIO =<< getUsedStorage store
+  ...
+  pure XFTPEnv {config, store, usedStorage, storeLog, ...}
+```
+
+### Startup Config Validation
+
+Following SMP's `checkMsgStoreMode` pattern, `Main.hs` validates config before starting:
+
+- **`store_files=database` + StoreLog file exists** (without `db_store_log=on`): Error — "StoreLog file present but store_files is `database`. Use `xftp-server database import` to migrate, or set `db_store_log: on`."
+- **`store_files=database` + schema doesn't exist**: Error — "Create schema in PostgreSQL or use `xftp-server database import`."
+- **`store_files=memory` + Postgres schema exists**: Warning — "Postgres schema exists but store_files is `memory`. Data in Postgres will not be used."
+- **Binary compiled without `server_postgres` + `store_files=database`**: Error — "Server not compiled with Postgres support."
+
+## Module Structure
+
+```
+src/Simplex/FileTransfer/Server/
+  Store.hs                    -- FileStoreClass typeclass + shared types (FileRec, FileRecipient, etc.)
+  Store/
+    STM.hs                    -- STMFileStore (extracted from current Store.hs)
+    Postgres.hs               -- PostgresFileStore                [CPP-guarded]
+    Postgres/
+      Migrations.hs           -- Schema migrations                [CPP-guarded]
+      Config.hs               -- PostgresFileStoreCfg             [CPP-guarded]
+  StoreLog.hs                 -- Unchanged (interchange format for both backends + migration)
+  Env.hs                      -- XFTPStoreConfig GADT, polymorphic XFTPEnv
+  Main.hs                     -- Store selection, migration CLI commands
+  Server.hs                   -- Polymorphic over FileStoreClass
+```
+
+## PostgreSQL Schema
+
+Initial migration (`20260325_initial`):
+
+```sql
+CREATE TABLE files (
+  sender_id BYTEA NOT NULL PRIMARY KEY,
+  file_size INT4 NOT NULL,
+  file_digest BYTEA NOT NULL,
+  sender_key BYTEA NOT NULL,
+  file_path TEXT,
+  created_at INT8 NOT NULL,
+  status TEXT NOT NULL DEFAULT 'active'
+);
+
+CREATE TABLE recipients (
+  recipient_id BYTEA NOT NULL PRIMARY KEY,
+  sender_id BYTEA NOT NULL REFERENCES files ON DELETE CASCADE,
+  recipient_key BYTEA NOT NULL
+);
+
+CREATE INDEX idx_recipients_sender_id ON recipients (sender_id);
+CREATE INDEX idx_files_created_at ON files (created_at);
+```
+
+- `file_size` is `INT4` matching `Word32` in `FileInfo.size`
+- `sender_key` and `recipient_key` stored as `BYTEA` using binary encoding via `C.encodePubKey` / `C.decodePubKey` (matching SMP's `ToField`/`FromField` instances for `APublicAuthKey` — includes algorithm type tag in the binary format)
+- `file_path` nullable (set after upload completes via `setFilePath`)
+- `ON DELETE CASCADE` for recipients when file is hard-deleted
+- `created_at` stores rounded epoch seconds (1-hour precision, `RoundedFileTime`)
+- `status` as TEXT via `StrEncoding` (`ServerEntityStatus`: `EntityActive`, `EntityBlocked info`, `EntityOff`)
+- Hard deletes (no `deleted_at` column)
+- No PL/pgSQL functions needed; `setFilePath` uses `WHERE file_path IS NULL` to prevent duplicate uploads (the `UPDATE` itself acquires a row-level lock)
+- `used_storage` computed on startup: `SELECT COALESCE(SUM(file_size), 0) FROM files` (matches STM `countUsedStorage` — all files, see usedStorage Ownership section)
+
+### Migrations Module
+
+Following SMP's `QueueStore/Postgres/Migrations.hs` pattern:
+
+```haskell
+module Simplex.FileTransfer.Server.Store.Postgres.Migrations
+  ( xftpServerMigrations,
+  )
+where
+
+import Data.List (sortOn)
+import Data.Text (Text)
+import Simplex.Messaging.Agent.Store.Shared
+import Text.RawString.QQ (r)
+
+xftpSchemaMigrations :: [(String, Text, Maybe Text)]
+xftpSchemaMigrations =
+  [ ("20260325_initial", m20260325_initial, Nothing)
+  ]
+
+xftpServerMigrations :: [Migration]
+xftpServerMigrations = sortOn name $ map migration xftpSchemaMigrations
+  where
+    migration (name, up, down) = Migration {name, up, down = down}
+
+m20260325_initial :: Text
+m20260325_initial =
+  [r|
+CREATE TABLE files (
+  sender_id BYTEA NOT NULL PRIMARY KEY,
+  ...
+);
+  |]
+```
+
+The `Migration` type (from `Simplex.Messaging.Agent.Store.Shared`) has fields `{name :: String, up :: Text, down :: Maybe Text}`. Initial migration has `Nothing` for `down`. Future migrations should include `Just down_migration` for rollback support. Called via `createDBStore dbOpts xftpServerMigrations (MigrationConfig confirmMigrations Nothing)`.
+
+### Postgres Operations
+
+Key query patterns:
+
+- **`addFile`**: `INSERT INTO files (...) VALUES (...)`, return `DUPLICATE_` on unique violation.
+- **`setFilePath`**: `UPDATE files SET file_path = ? WHERE sender_id = ? AND file_path IS NULL`, verified with `assertUpdated` (returns `AUTH` if 0 rows affected — file not found or already uploaded). The `WHERE file_path IS NULL` prevents duplicate uploads; the `UPDATE` acquires a row lock implicitly. Only persists the path; `usedStorage` managed by server.
+- **`addRecipient`**: `INSERT INTO recipients (...)`, plus check for duplicates. No need for `recipientIds` TVar update — Postgres derives it from the table.
+- **`getFile`** (sender): `SELECT ... FROM files WHERE sender_id = ?`, returns auth key from `sender_key` column.
+- **`getFile`** (recipient): `SELECT f.*, r.recipient_key FROM recipients r JOIN files f ON ... WHERE r.recipient_id = ?`.
+- **`deleteFile`**: `DELETE FROM files WHERE sender_id = ?` (recipients cascade).
+- **`blockFile`**: `UPDATE files SET status = ? WHERE sender_id = ?`. When `deleted = True`, the server adjusts `usedStorage` externally (matching current STM behavior where `blockFile` only updates status and storage, not `filePath`).
+- **`expiredFiles`**: `SELECT sender_id, file_path, file_size FROM files WHERE created_at + ? < ? LIMIT ?` — batched query replaces per-file iteration, includes `file_size` for `usedStorage` adjustment. Called in a loop until no rows returned.
+
+## INI Configuration
+
+New keys in `[STORE_LOG]` section:
+
+```ini
+[STORE_LOG]
+enable: on
+store_files: memory            # memory | database
+db_connection: postgresql://xftp@/xftp_server_store
+db_schema: xftp_server
+db_pool_size: 10
+db_store_log: off
+expire_files_hours: 48
+```
+
+`store_files` selects the backend (`store_files` rather than `store_queues` because XFTP stores files, not queues):
+- `memory` -> `XSCMemory` (current behavior)
+- `database` -> `XSCDatabase` (requires `server_postgres` build flag)
+
+### INI Template Generation (`xftp-server init`)
+
+The `iniFileContent` function in `Main.hs` must be updated to generate the new keys in the `[STORE_LOG]` section. Following SMP's `iniDbOpts` pattern with `optDisabled'` (prefixes `"# "` when value equals default), Postgres keys are generated commented out by default:
+
+```ini
+[STORE_LOG]
+enable: on
+
+# File storage mode: `memory` or `database` (PostgreSQL).
+store_files: memory
+
+# Database connection settings for PostgreSQL database (`store_files: database`).
+# db_connection: postgresql://xftp@/xftp_server_store
+# db_schema: xftp_server
+# db_pool_size: 10
+
+# Write database changes to store log file
+# db_store_log: off
+
+expire_files_hours: 48
+```
+
+Reuses `iniDBOptions` from `Simplex.Messaging.Server.CLI` for runtime parsing (falls back to defaults when keys are commented out or missing). `enableDbStoreLog'` pattern (`settingIsOn "STORE_LOG" "db_store_log"`) controls `dbStoreLogPath`.
+
+### PostgresFileStoreCfg
+
+```haskell
+data PostgresFileStoreCfg = PostgresFileStoreCfg
+  { dbOpts :: DBOpts,
+    dbStoreLogPath :: Maybe FilePath,
+    confirmMigrations :: MigrationConfirmation
+  }
+```
+
+No `deletedTTL` (hard deletes).
+
+### Default DB Options
+
+```haskell
+defaultXFTPDBOpts :: DBOpts
+defaultXFTPDBOpts =
+  DBOpts
+    { connstr = "postgresql://xftp@/xftp_server_store",
+      schema = "xftp_server",
+      poolSize = 10,
+      createSchema = False
+    }
+```
+
+## Migration CLI
+
+Bidirectional migration via StoreLog as interchange format:
+
+```
+xftp-server database import [--database DB_CONN] [--schema DB_SCHEMA] [--pool-size N]
+xftp-server database export [--database DB_CONN] [--schema DB_SCHEMA] [--pool-size N]
+```
+
+No `--table` flag needed (unlike SMP which has queues/messages/all) — XFTP has a single entity type (files + recipients, always migrated together).
+
+CLI options reuse `dbOptsP` parser from `Simplex.Messaging.Server.CLI`.
+
+### Import (StoreLog -> PostgreSQL)
+
+1. Confirm: prompt user with database connection details and StoreLog path
+2. Read and replay StoreLog into temporary `STMFileStore`
+3. Connect to PostgreSQL, run schema migrations (`createSchema = True`, `confirmMigrations = MCYesUp`)
+4. Batch-insert file records into `files` table using PostgreSQL COPY protocol (matching SMP's `batchInsertQueues` pattern for performance). Progress reported every 10k files.
+5. Batch-insert recipient records into `recipients` table using COPY protocol
+6. Verify counts: `SELECT COUNT(*) FROM files` / `recipients` — warn if mismatch
+7. Rename StoreLog to `.bak` (prevents accidental re-import, preserves original for rollback)
+8. Report counts
+
+### Export (PostgreSQL -> StoreLog)
+
+1. Confirm: prompt user with database connection details and output path. Fail if output file already exists.
+2. Connect to PostgreSQL
+3. Open new StoreLog file for writing
+4. Fold over all file records, writing per file (in this order, matching existing `writeFileStore`): `AddFile` (with `ServerEntityStatus` — this preserves `EntityBlocked` state), `AddRecipients`, then `PutFile` (if `file_path` is set)
+5. Report counts
+
+Note: `AddFile` carries `ServerEntityStatus` which includes `EntityBlocked info`, so blocking state is preserved through export/import without needing separate `BlockFile` log entries.
+
+File data on disk is untouched by migration — only metadata moves between backends.
+
+## Cabal Integration
+
+Shared `server_postgres` flag. New Postgres modules added to existing conditional block:
+
+```cabal
+if flag(server_postgres)
+  cpp-options: -DdbServerPostgres
+  exposed-modules:
+    ...existing SMP modules...
+    Simplex.FileTransfer.Server.Store.Postgres
+    Simplex.FileTransfer.Server.Store.Postgres.Migrations
+    Simplex.FileTransfer.Server.Store.Postgres.Config
+```
+
+CPP guards (`#if defined(dbServerPostgres)`) in:
+- `Store.hs` — Postgres `FromField`/`ToField` instances for XFTP-specific types if needed
+- `Env.hs` — `XSCDatabase` constructor
+- `Main.hs` — database CLI commands, store selection for `database` mode, Postgres imports
+- `Server.hs` — Postgres-specific imports if needed
+
+## Testing
+
+- **Parameterized server tests**: Existing `xftpServerTests` refactored to accept a store type parameter (following SMP's `SpecWith (ASrvTransport, AStoreType)` pattern). The same server tests run against both STM and Postgres backends — STM tests run unconditionally, Postgres tests added under `#if defined(dbServerPostgres)` with `postgressBracket` for database lifecycle (drop → create → test → drop).
+- **Unit tests**: `PostgresFileStore` operations — add/get/delete/block/expire, duplicate detection, auth errors
+- **Migration round-trip**: STM store → export to StoreLog → import to Postgres → export back → verify StoreLog equality (including blocked file status)
+- **Tests location**: in `tests/` alongside existing XFTP tests, guarded by `server_postgres` CPP flag
+- **Test database**: PostgreSQL on `localhost:5432`, using a dedicated `xftp_server_test` schema (dropped and recreated per test run via `postgressBracket`, following SMP's test database lifecycle pattern)
+- **Test fixtures**: `testXFTPStoreDBOpts :: DBOpts` with `createSchema = True`, `confirmMigrations = MCYesUp`, in `tests/XFTPClient.hs`
@@ -0,0 +1,648 @@
+# XFTP PostgreSQL Backend — Implementation Plan
+
+> **For agentic workers:** REQUIRED: Use superpowers-extended-cc:subagent-driven-development (if subagents available) or superpowers-extended-cc:executing-plans to implement this plan. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add PostgreSQL backend support to xftp-server as an alternative to STM + StoreLog, with bidirectional migration.
+
+**Architecture:** Introduce `FileStoreClass` typeclass (IO-based, following `QueueStoreClass` pattern). Extract current STM store into `Store/STM.hs`, make `Server.hs` polymorphic, then add `Store/Postgres.hs` behind `server_postgres` CPP flag. `usedStorage` moves from store to `XFTPEnv` so the server manages quota tracking externally.
+
+**Tech Stack:** Haskell, postgresql-simple, STM, fourmolu, cabal with CPP flags
+
+**Design spec:** `plans/2026-03-25-xftp-postgres-backend-design.md`
+
+---
+
+## File Structure
+
+**Existing files modified:**
+- `src/Simplex/FileTransfer/Server/Store.hs` — rewritten: becomes typeclass + shared types
+- `src/Simplex/FileTransfer/Server/Env.hs` — polymorphic `XFTPEnv s`, `XFTPStoreConfig` GADT
+- `src/Simplex/FileTransfer/Server.hs` — polymorphic over `FileStoreClass s`
+- `src/Simplex/FileTransfer/Server/StoreLog.hs` — update for IO store functions
+- `src/Simplex/FileTransfer/Server/Main.hs` — INI config, dispatch, CLI commands
+- `simplexmq.cabal` — new modules
+- `tests/XFTPClient.hs` — Postgres test fixtures
+- `tests/Test.hs` — Postgres test group
+
+**New files created:**
+- `src/Simplex/FileTransfer/Server/Store/STM.hs` — `STMFileStore` (extracted from current `Store.hs`)
+- `src/Simplex/FileTransfer/Server/Store/Postgres.hs` — `PostgresFileStore` [CPP-guarded]
+- `src/Simplex/FileTransfer/Server/Store/Postgres/Config.hs` — `PostgresFileStoreCfg` [CPP-guarded]
+- `src/Simplex/FileTransfer/Server/Store/Postgres/Migrations.hs` — schema SQL [CPP-guarded]
+- `tests/CoreTests/XFTPStoreTests.hs` — Postgres store unit tests [CPP-guarded]
+
+---
+
+## Task 1: Move `usedStorage` from `FileStore` to `XFTPEnv`
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Store.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+- Modify: `src/Simplex/FileTransfer/Server.hs`
+
+- [ ] **Step 1: Remove `usedStorage` from `FileStore` in `Store.hs`**
+
+  1. Remove `usedStorage :: TVar Int64` field from `FileStore` record (line 47).
+  2. Remove `usedStorage <- newTVarIO 0` from `newFileStore` (line 75) and drop the field from the record construction (line 76).
+  3. In `setFilePath` (line 92-97): remove `modifyTVar' (usedStorage st) (+ fromIntegral (size fileInfo))` — keep only `writeTVar filePath (Just fPath)`. Change pattern from `\FileRec {fileInfo, filePath}` to `\FileRec {filePath}` (fileInfo is now unused — `-Wunused-matches` error).
+  4. In `deleteFile` (line 112-119): remove `modifyTVar' usedStorage $ subtract (fromIntegral $ size fileInfo)`. Change outer pattern match from `FileStore {files, recipients, usedStorage}` to `FileStore {files, recipients}`. Change inner pattern from `Just FileRec {fileInfo, recipientIds}` to `Just FileRec {recipientIds}` (`fileInfo` is now unused — `-Wunused-matches` error).
+  5. In `blockFile` (line 122-127): remove `when deleted $ modifyTVar' usedStorage $ subtract (fromIntegral $ size fileInfo)`. Change pattern match from `st@FileStore {usedStorage}` to `st`. The `deleted` parameter and `fileInfo` in the inner pattern become unused — prefix with `_` or remove from pattern to avoid `-Wunused-matches`.
+
+- [ ] **Step 2: Add `usedStorage` to `XFTPEnv` in `Env.hs`**
+
+  1. Add `usedStorage :: TVar Int64` field to `XFTPEnv` record (between `store` and `storeLog`, line 93).
+  2. In `newXFTPServerEnv` (line 112-126): replace lines 117-118:
+     ```
+     used <- countUsedStorage <$> readTVarIO (files store)
+     atomically $ writeTVar (usedStorage store) used
+     ```
+     with:
+     ```
+     usedStorage <- newTVarIO =<< countUsedStorage <$> readTVarIO (files store)
+     ```
+  3. Add `usedStorage` to the `pure XFTPEnv {..}` construction.
+
+- [ ] **Step 3: Update all `usedStorage` access sites in `Server.hs`**
+
+  1. Line 552: `us <- asks $ usedStorage . store` → `us <- asks usedStorage`.
+  2. Line 569: `us <- asks $ usedStorage . store` → `us <- asks usedStorage`.
+  3. Line 639: `usedStart <- readTVarIO $ usedStorage st` → `usedStart <- readTVarIO =<< asks usedStorage`.
+  4. Line 647: `usedEnd <- readTVarIO $ usedStorage st` → `usedEnd <- readTVarIO =<< asks usedStorage`.
+  5. Line 694: `FileStore {files, usedStorage} <- asks store` → split into `FileStore {files} <- asks store` and `usedStorage <- asks usedStorage`.
+  6. In `deleteOrBlockServerFile_` (line 620): after `void $ atomically $ storeAction st`, add usedStorage adjustment — `us <- asks usedStorage` then `atomically $ modifyTVar' us $ subtract (fromIntegral $ size fileInfo)` when file had a path (check `path` from `readTVarIO filePath` earlier in the function).
+
+- [ ] **Step 4: Build and verify**
+
+  Run: `cabal build`
+
+- [ ] **Step 5: Run existing tests**
+
+  Run: `cabal test --test-show-details=streaming --test-option=--match="/XFTP/"`
+
+- [ ] **Step 6: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs
+  git add src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs
+  git commit -m "refactor(xftp): move usedStorage from FileStore to XFTPEnv"
+  ```
+
+---
+
+## Task 2: Add `getUsedStorage`, `getFileCount`, `expiredFiles` functions
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Store.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+- Modify: `src/Simplex/FileTransfer/Server.hs`
+
+- [ ] **Step 1: Add three new functions to `Store.hs`**
+
+  1. Add to exports: `getUsedStorage`, `getFileCount`, `expiredFiles`.
+  2. Remove `expiredFilePath` from exports AND delete the function definition (dead code → `-Wunused-binds` error). Also remove `($>>=)` from import `Simplex.Messaging.Util (ifM, ($>>=))` → `Simplex.Messaging.Util (ifM)` — `$>>=` was only used by `expiredFilePath`.
+  3. Add import: `qualified Data.Map.Strict as M` (needed for `M.foldl'` in `getUsedStorage` and `M.toList` in `expiredFiles`).
+  4. Implement:
+     ```haskell
+     getUsedStorage :: FileStore -> IO Int64
+     getUsedStorage FileStore {files} =
+       M.foldl' (\acc FileRec {fileInfo = FileInfo {size}} -> acc + fromIntegral size) 0 <$> readTVarIO files
+
+     getFileCount :: FileStore -> IO Int
+     getFileCount FileStore {files} = M.size <$> readTVarIO files
+
+     expiredFiles :: FileStore -> Int64 -> Int -> IO [(SenderId, Maybe FilePath, Word32)]
+     expiredFiles FileStore {files} old _limit = do
+       fs <- readTVarIO files
+       fmap catMaybes . forM (M.toList fs) $ \(sId, FileRec {fileInfo = FileInfo {size}, filePath, createdAt = RoundedSystemTime createdAt}) ->
+         if createdAt + fileTimePrecision < old
+           then do
+             path <- readTVarIO filePath
+             pure $ Just (sId, path, size)
+           else pure Nothing
+     ```
+  5. Add imports: `Data.Maybe (catMaybes)`, `Data.Word (Word32)` (note: `qualified Data.Map.Strict as M` already added in item 3).
+
+- [ ] **Step 2: Replace `countUsedStorage` in `Env.hs`**
+
+  1. Replace `countUsedStorage <$> readTVarIO (files store)` with `getUsedStorage store` in `newXFTPServerEnv`.
+  2. Remove `countUsedStorage` function definition and its export.
+  3. Remove `qualified Data.Map.Strict as M` import if no longer used.
+
+- [ ] **Step 3: Update `restoreServerStats` in `Server.hs` to use `getFileCount`**
+
+  In `restoreServerStats` (line 694-696): replace `FileStore {files} <- asks store` and `_filesCount <- M.size <$> readTVarIO files` with `st <- asks store` and `_filesCount <- liftIO $ getFileCount st` (eliminates the `FileStore` pattern match — `files` binding no longer needed).
+
+- [ ] **Step 4: Replace `expireServerFiles` iteration in `Server.hs`**
+
+  1. Replace the body of `expireServerFiles` (lines 636-660). Remove `files' <- readTVarIO (files st)` and the `forM_ (M.keys files')` loop.
+  2. New body: call `expiredFiles st old 10000` in a loop. For each `(sId, filePath_, fileSize)` in returned list: apply `itemDelay`, remove disk file if present, call `atomically $ deleteFile st sId`, adjust `usedStorage` TVar by `fileSize`, increment `filesExpired` stat. Loop until `expiredFiles` returns `[]`.
+  3. Remove `Data.Map.Strict` import from Server.hs if no longer needed (was used for `M.size` and `M.keys` — now replaced by `getFileCount` and `expiredFiles`).
+
+- [ ] **Step 5: Build and verify**
+
+  Run: `cabal build`
+
+- [ ] **Step 6: Run existing tests**
+
+  Run: `cabal test --test-show-details=streaming --test-option=--match="/XFTP/"`
+
+- [ ] **Step 7: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs
+  git add src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs
+  git commit -m "refactor(xftp): add getUsedStorage, getFileCount, expiredFiles store functions"
+  ```
+
+---
+
+## Task 3: Change `Store.hs` functions from STM to IO
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Store.hs`
+- Modify: `src/Simplex/FileTransfer/Server.hs`
+- Modify: `src/Simplex/FileTransfer/Server/StoreLog.hs`
+
+- [ ] **Step 1: Change all Store.hs function signatures from STM to IO**
+
+  For each of: `addFile`, `setFilePath`, `addRecipient`, `getFile`, `deleteFile`, `blockFile`, `deleteRecipient`, `ackFile`:
+  1. Change return type from `STM (Either XFTPErrorType ...)` to `IO (Either XFTPErrorType ...)` (or `STM ()` to `IO ()` for `deleteRecipient`).
+  2. Wrap the function body in `atomically $ do ...`.
+  3. Keep `withFile` and `newFileRec` as internal STM helpers (called inside the `atomically` blocks).
+
+- [ ] **Step 2: Update Server.hs call sites — remove `atomically` wrappers**
+
+  1. Line 563 (`receiveServerFile`): change `atomically $ writeTVar filePath (Just fPath)` → add `st <- asks store` then `void $ liftIO $ setFilePath st senderId fPath` (design call site #1 — `store` is not in scope in `receiveServerFile`'s `receive` helper, so bind via `asks`; `void` avoids `-Wunused-do-bind` warning on the `Either` result).
+  2. Line 453 (`verifyXFTPTransmission`): split `atomically $ verify =<< getFile st party fId` into: `liftIO (getFile st party fId)` (IO→M lift), then pattern match on result, use `readTVarIO (fileStatus fr)` instead of `readTVar`.
+  3. Lines 371, 377 (control port `CPDelete`/`CPBlock`): change `ExceptT $ atomically $ getFile fs SFRecipient fileId` → `ExceptT $ liftIO $ getFile fs SFRecipient fileId` (inside `unliftIO u $ do` block which runs in M monad — `liftIO` required to lift IO into M).
+  4. Line 508 (`addFile` in `createFile`): the `ExceptT $ addFile st sId file ts EntityActive` — `addFile` is now IO, `ExceptT` wraps IO directly. Remove any `atomically`.
+  5. Line 514 (`addRecipient`): same — `ExceptT . addRecipient st sId` works directly in IO.
+  6. Line 516 (`retryAdd`): change parameter type from `(XFTPFileId -> STM (Either XFTPErrorType a))` to `(XFTPFileId -> IO (Either XFTPErrorType a))`. Line 520: change `atomically (add fId)` to `liftIO (add fId)`.
+  7. Line 605 (`ackFileReception`): change `atomically $ deleteRecipient st rId fr` to `liftIO $ deleteRecipient st rId fr`.
+  8. Line 620 (`deleteOrBlockServerFile_`): change third parameter type from `(FileStore -> STM (Either XFTPErrorType ()))` to `(FileStore -> IO (Either XFTPErrorType ()))`. Line 626: change `void $ atomically $ storeAction st` to `void $ liftIO $ storeAction st`.
+  9. `expireServerFiles` `delete` helper: change `atomically $ deleteFile st sId` to `liftIO $ deleteFile st sId` (deleteFile is now IO; `liftIO` required because the helper runs in M monad, not IO).
+
+- [ ] **Step 3: Update `StoreLog.hs` — remove `atomically` from replay**
+
+  In `readFileStore` (line 93), function `addToStore`:
+  1. Change `atomically (addToStore lr)` to `addToStore lr` — store functions are now IO.
+  2. The `addToStore` body calls `addFile`, `setFilePath`, `deleteFile`, `blockFile`, `ackFile` — all IO now, no `atomically` needed.
+  3. For `AddRecipients`: `runExceptT $ mapM_ (ExceptT . addRecipient st sId) rcps` — `addRecipient` returns `IO (Either ...)`, so `ExceptT . addRecipient st sId` works directly.
+
+- [ ] **Step 4: Build and verify**
+
+  Run: `cabal build`
+
+- [ ] **Step 5: Run existing tests**
+
+  Run: `cabal test --test-show-details=streaming --test-option=--match="/XFTP/"`
+
+- [ ] **Step 6: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/StoreLog.hs
+  git add src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/StoreLog.hs
+  git commit -m "refactor(xftp): change file store operations from STM to IO"
+  ```
+
+---
+
+## Task 4: Extract `FileStoreClass` typeclass, move STM impl to `Store/STM.hs`
+
+**Files:**
+- Rewrite: `src/Simplex/FileTransfer/Server/Store.hs`
+- Create: `src/Simplex/FileTransfer/Server/Store/STM.hs`
+- Modify: `src/Simplex/FileTransfer/Server/StoreLog.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+- Modify: `src/Simplex/FileTransfer/Server.hs`
+- Modify: `simplexmq.cabal`
+
+- [ ] **Step 1: Create `Store/STM.hs` — move all implementation code**
+
+  1. Create directory `src/Simplex/FileTransfer/Server/Store/`.
+  2. Create `src/Simplex/FileTransfer/Server/Store/STM.hs`.
+  3. Move from `Store.hs`: `FileStore` data type (rename to `STMFileStore`), all function implementations, internal helpers (`withFile`, `newFileRec`), all STM-specific imports.
+  4. Rename all `FileStore` references to `STMFileStore` in the new file.
+  5. Module declaration: `module Simplex.FileTransfer.Server.Store.STM` exporting only `STMFileStore (..)` — do NOT export standalone functions (`addFile`, `setFilePath`, etc.) to avoid name collisions with the typeclass methods from `Store.hs`.
+
+- [ ] **Step 2: Rewrite `Store.hs` as the typeclass module**
+
+  1. Add `{-# LANGUAGE TypeFamilies #-}` pragma to `Store.hs` (required for `type FileStoreConfig s` associated type).
+  2. Keep in `Store.hs`: `FileRec (..)`, `FileRecipient (..)`, `RoundedFileTime`, `fileTimePrecision` definitions and their `StrEncoding` instance.
+  3. Add `FileStoreClass` typeclass:
+     ```haskell
+     class FileStoreClass s where
+       type FileStoreConfig s
+
+       -- Lifecycle
+       newFileStore :: FileStoreConfig s -> IO s
+       closeFileStore :: s -> IO ()
+
+       -- File operations
+       addFile :: s -> SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> IO (Either XFTPErrorType ())
+       setFilePath :: s -> SenderId -> FilePath -> IO (Either XFTPErrorType ())
+       addRecipient :: s -> SenderId -> FileRecipient -> IO (Either XFTPErrorType ())
+       getFile :: s -> SFileParty p -> XFTPFileId -> IO (Either XFTPErrorType (FileRec, C.APublicAuthKey))
+       deleteFile :: s -> SenderId -> IO (Either XFTPErrorType ())
+       blockFile :: s -> SenderId -> BlockingInfo -> Bool -> IO (Either XFTPErrorType ())
+       deleteRecipient :: s -> RecipientId -> FileRec -> IO ()
+       ackFile :: s -> RecipientId -> IO (Either XFTPErrorType ())
+
+       -- Expiration
+       expiredFiles :: s -> Int64 -> Int -> IO [(SenderId, Maybe FilePath, Word32)]
+
+       -- Stats
+       getUsedStorage :: s -> IO Int64
+       getFileCount :: s -> IO Int
+     ```
+  4. Do NOT re-export from `Store/STM.hs` — this would create a circular module dependency (Store.hs imports Store/STM.hs, Store/STM.hs imports Store.hs). Consumers must import `Store.STM` directly where they need `STMFileStore`.
+  5. Remove all STM-specific imports that are no longer needed.
+
+- [ ] **Step 3: Add `FileStoreClass` instance in `Store/STM.hs`**
+
+  1. Import `FileStoreClass` from `Simplex.FileTransfer.Server.Store`.
+  2. Inline all implementations directly in the instance body (do NOT delegate to standalone functions — the standalone names collide with typeclass method names, causing ambiguous occurrences for importers):
+     ```haskell
+     instance FileStoreClass STMFileStore where
+       type FileStoreConfig STMFileStore = ()
+       newFileStore () = do
+         files <- TM.emptyIO
+         recipients <- TM.emptyIO
+         pure STMFileStore {files, recipients}
+       closeFileStore _ = pure ()
+       addFile st sId fileInfo createdAt status = atomically $ ...
+       setFilePath st sId fPath = atomically $ ...
+       -- ... (each method's body is the existing function body, inlined)
+     ```
+  3. Remove the standalone top-level function definitions — they are now instance methods. Keep only `withFile` and `newFileRec` as internal helpers used by the instance methods.
+
+- [ ] **Step 4: Update importers**
+
+  1. `Env.hs`: add `import Simplex.FileTransfer.Server.Store.STM (STMFileStore (..))`. Change `FileStore` → `STMFileStore` in `XFTPEnv` type and `newXFTPServerEnv`. Change `store <- newFileStore` to `store <- newFileStore ()` (typeclass method now takes `FileStoreConfig STMFileStore` which is `()`). Keep `import Simplex.FileTransfer.Server.Store` for `FileRec`, `FileRecipient`, `FileStoreClass`, etc.
+  2. `Server.hs`: add `import Simplex.FileTransfer.Server.Store.STM`. Change `FileStore` → `STMFileStore` in any explicit type annotations. Import `FileStoreClass` from `Simplex.FileTransfer.Server.Store`.
+  3. `StoreLog.hs`: add `import Simplex.FileTransfer.Server.Store.STM` to access concrete `STMFileStore` type and store functions used during log replay. Change `FileStore` → `STMFileStore` in `readWriteFileStore` and `writeFileStore` parameter types.
+
+- [ ] **Step 5: Update cabal file**
+
+  Add `Simplex.FileTransfer.Server.Store.STM` to `exposed-modules` in the `!flag(client_library)` section, alongside existing XFTP server modules.
+
+- [ ] **Step 6: Build and verify**
+
+  Run: `cabal build`
+
+- [ ] **Step 7: Run existing tests**
+
+  Run: `cabal test --test-show-details=streaming --test-option=--match="/XFTP/"`
+
+- [ ] **Step 8: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Store/STM.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/StoreLog.hs
+  git add src/Simplex/FileTransfer/Server/Store.hs src/Simplex/FileTransfer/Server/Store/STM.hs src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/StoreLog.hs simplexmq.cabal
+  git commit -m "refactor(xftp): extract FileStoreClass typeclass, move STM impl to Store.STM"
+  ```
+
+---
+
+## Task 5: Make `XFTPEnv` and `Server.hs` polymorphic over `FileStoreClass`
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+- Modify: `src/Simplex/FileTransfer/Server.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Main.hs`
+- Modify: `tests/XFTPClient.hs` (if it calls `runXFTPServerBlocking` directly)
+
+- [ ] **Step 1: Make `XFTPEnv` polymorphic in `Env.hs`**
+
+  1. Add `XFTPStoreConfig` GADT: `data XFTPStoreConfig s where XSCMemory :: Maybe FilePath -> XFTPStoreConfig STMFileStore`.
+  2. Change `data XFTPEnv` to `data XFTPEnv s` — field `store :: FileStore` becomes `store :: s`.
+  3. Change `newXFTPServerEnv :: XFTPServerConfig -> IO XFTPEnv` to `newXFTPServerEnv :: FileStoreClass s => XFTPStoreConfig s -> XFTPServerConfig -> IO (XFTPEnv s)`.
+  4. Pattern match on `XSCMemory storeLogPath` in `newXFTPServerEnv` body. Create store via `newFileStore ()`, storeLog via `mapM (`readWriteFileStore` st) storeLogPath`.
+
+- [ ] **Step 2: Make `Server.hs` polymorphic**
+
+  1. Change `type M a = ReaderT XFTPEnv IO a` to `type M s a = ReaderT (XFTPEnv s) IO a`.
+  2. Add `FileStoreClass s =>` constraint to all functions using `M s a`. Use `forall s.` in signatures of functions that have `where`-block bindings with `M s` type annotations — `ScopedTypeVariables` requires explicit `forall` to bring `s` into scope for inner type signatures (matching SMP's `smpServer :: forall s. MsgStoreClass s => ...` pattern). Full list: `xftpServer`, `processRequest`, `verifyXFTPTransmission`, `processXFTPRequest` and all its `where`-bound functions (`createFile`, `addRecipients`, `receiveServerFile`, `sendServerFile`, `deleteServerFile`, `ackFileReception`, `retryAdd`, `addFileRetry`, `addRecipientRetry`), `deleteServerFile_`, `blockServerFile`, `deleteOrBlockServerFile_`, `expireServerFiles`, `randomId`, `getFileId`, `withFileLog`, `incFileStat`, `saveServerStats`, `restoreServerStats`, `randomDelay` (inside `#ifdef slow_servers` CPP block). Also update `encodeXftp` (line 236) and `runCPClient` (line 339) which use explicit `ReaderT XFTPEnv IO` instead of the `M` alias — change to `ReaderT (XFTPEnv s) IO`.
+  3. Change `runXFTPServerBlocking` and `runXFTPServer` to take `XFTPStoreConfig s` parameter.
+  4. Add `closeFileStore store` call to the server shutdown path (in the `finally` block or `stopServer` equivalent — after saving stats, before logging "Server stopped"). This ensures Postgres connection pool and `dbStoreLog` are properly closed. For STM this is a no-op.
+
+- [ ] **Step 3: Update `Main.hs` dispatch**
+
+  1. In `runServer`: construct `XSCMemory (enableStoreLog $> storeLogFilePath)`.
+  2. Add dispatch function that calls the updated `runXFTPServer` (which creates `started` internally):
+     ```haskell
+     run :: FileStoreClass s => XFTPStoreConfig s -> IO ()
+     run storeCfg = runXFTPServer storeCfg serverConfig
+     ```
+  3. Call `run` with the `XSCMemory` config.
+
+- [ ] **Step 4: Update test helper if needed**
+
+  If `tests/XFTPClient.hs` calls `runXFTPServerBlocking` directly, update the call to pass an `XSCMemory` config. Check the `withXFTPServer` / `serverBracket` helper.
+
+- [ ] **Step 5: Build and verify**
+
+  Run: `cabal build && cabal build test:simplexmq-test`
+
+- [ ] **Step 6: Run existing tests**
+
+  Run: `cabal test --test-show-details=streaming --test-option=--match="/XFTP/"`
+
+- [ ] **Step 7: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/Main.hs
+  git add src/Simplex/FileTransfer/Server/Env.hs src/Simplex/FileTransfer/Server.hs src/Simplex/FileTransfer/Server/Main.hs tests/XFTPClient.hs simplexmq.cabal
+  git commit -m "refactor(xftp): make XFTPEnv and server polymorphic over FileStoreClass"
+  ```
+
+---
+
+## Task 6: Add Postgres config, migrations, and store skeleton
+
+**Files:**
+- Create: `src/Simplex/FileTransfer/Server/Store/Postgres/Config.hs`
+- Create: `src/Simplex/FileTransfer/Server/Store/Postgres/Migrations.hs`
+- Create: `src/Simplex/FileTransfer/Server/Store/Postgres.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+- Modify: `simplexmq.cabal`
+
+- [ ] **Step 1: Create `Store/Postgres/Config.hs`**
+
+  ```haskell
+  module Simplex.FileTransfer.Server.Store.Postgres.Config
+    ( PostgresFileStoreCfg (..),
+      defaultXFTPDBOpts,
+    )
+  where
+
+  import Simplex.Messaging.Agent.Store.Postgres.Options (DBOpts (..))
+  import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation)
+
+  data PostgresFileStoreCfg = PostgresFileStoreCfg
+    { dbOpts :: DBOpts,
+      dbStoreLogPath :: Maybe FilePath,
+      confirmMigrations :: MigrationConfirmation
+    }
+
+  defaultXFTPDBOpts :: DBOpts
+  defaultXFTPDBOpts =
+    DBOpts
+      { connstr = "postgresql://xftp@/xftp_server_store",
+        schema = "xftp_server",
+        poolSize = 10,
+        createSchema = False
+      }
+  ```
+
+- [ ] **Step 2: Create `Store/Postgres/Migrations.hs`**
+
+  Full migration module with `xftpServerMigrations :: [Migration]` and `m20260325_initial` containing CREATE TABLE SQL for `files` and `recipients` tables plus indexes. Follow SMP's `QueueStore/Postgres/Migrations.hs` pattern exactly: tuple list → `sortOn name . map migration`.
+
+- [ ] **Step 3: Create `Store/Postgres.hs` with stub instance**
+
+  1. Define `PostgresFileStore` with `dbStore :: DBStore` and `dbStoreLog :: Maybe (StoreLog 'WriteMode)`.
+  2. `instance FileStoreClass PostgresFileStore` with `error "not implemented"` for all methods except `newFileStore` (calls `createDBStore` + opens `dbStoreLog`) and `closeFileStore` (closes both). `type FileStoreConfig PostgresFileStore = PostgresFileStoreCfg`.
+  3. Add `withDB`, `handleDuplicate`, `assertUpdated`, `withLog` helpers.
+
+- [ ] **Step 4: Add `XSCDatabase` GADT constructor in `Env.hs` (CPP-guarded)**
+
+  ```haskell
+  #if defined(dbServerPostgres)
+  import Simplex.FileTransfer.Server.Store.Postgres (PostgresFileStore)
+  import Simplex.FileTransfer.Server.Store.Postgres.Config (PostgresFileStoreCfg)
+  #endif
+
+  data XFTPStoreConfig s where
+    XSCMemory :: Maybe FilePath -> XFTPStoreConfig STMFileStore
+  #if defined(dbServerPostgres)
+    XSCDatabase :: PostgresFileStoreCfg -> XFTPStoreConfig PostgresFileStore
+  #endif
+  ```
+
+- [ ] **Step 5: Update cabal**
+
+  Add to existing `if flag(server_postgres)` block:
+  ```
+  Simplex.FileTransfer.Server.Store.Postgres
+  Simplex.FileTransfer.Server.Store.Postgres.Config
+  Simplex.FileTransfer.Server.Store.Postgres.Migrations
+  ```
+
+- [ ] **Step 6: Build both ways**
+
+  Run: `cabal build && cabal build -fserver_postgres`
+
+- [ ] **Step 7: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store/Postgres.hs src/Simplex/FileTransfer/Server/Store/Postgres/Config.hs src/Simplex/FileTransfer/Server/Env.hs
+  git add src/Simplex/FileTransfer/Server/Store/Postgres.hs src/Simplex/FileTransfer/Server/Store/Postgres/Config.hs src/Simplex/FileTransfer/Server/Store/Postgres/Migrations.hs src/Simplex/FileTransfer/Server/Env.hs simplexmq.cabal
+  git commit -m "feat(xftp): add PostgreSQL store skeleton with schema migration"
+  ```
+
+---
+
+## Task 7: Implement `PostgresFileStore` operations
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Store/Postgres.hs`
+
+- [ ] **Step 1: Implement `addFile`**
+
+  `INSERT INTO files (sender_id, file_size, file_digest, sender_key, file_path, created_at, status) VALUES (?,?,?,?,NULL,?,?)`. Catch unique violation with `handleDuplicate` → `DUPLICATE_`. Call `withLog "addFile"` after.
+
+- [ ] **Step 2: Implement `getFile`**
+
+  For `SFSender`: `SELECT ... FROM files WHERE sender_id = ?`. Construct `FileRec` with `newTVarIO` per TVar field. `recipientIds = S.empty`.
+  For `SFRecipient`: `SELECT f.*, r.recipient_key FROM recipients r JOIN files f ON r.sender_id = f.sender_id WHERE r.recipient_id = ?`.
+
+- [ ] **Step 3: Implement `setFilePath`**
+
+  `UPDATE files SET file_path = ? WHERE sender_id = ? AND file_path IS NULL`. Use `assertUpdated`. Call `withLog "setFilePath"`.
+
+- [ ] **Step 4: Implement `addRecipient`**
+
+  `INSERT INTO recipients (recipient_id, sender_id, recipient_key) VALUES (?,?,?)`. `handleDuplicate` → `DUPLICATE_`. Call `withLog "addRecipient"`.
+
+- [ ] **Step 5: Implement `deleteFile`, `blockFile`**
+
+  `deleteFile`: `DELETE FROM files WHERE sender_id = ?` (CASCADE). `withLog "deleteFile"`.
+  `blockFile`: `UPDATE files SET status = ? WHERE sender_id = ?`. `assertUpdated`. `withLog "blockFile"`.
+
+- [ ] **Step 6: Implement `deleteRecipient`, `ackFile`**
+
+  `deleteRecipient`: `DELETE FROM recipients WHERE recipient_id = ?`. `withLog "deleteRecipient"`.
+  `ackFile`: same + return `Left AUTH` if 0 rows.
+
+- [ ] **Step 7: Implement `expiredFiles`, `getUsedStorage`, `getFileCount`**
+
+  `expiredFiles`: `SELECT sender_id, file_path, file_size FROM files WHERE created_at + ? < ? LIMIT ?`.
+  `getUsedStorage`: `SELECT COALESCE(SUM(file_size), 0) FROM files`.
+  `getFileCount`: `SELECT COUNT(*) FROM files`.
+
+- [ ] **Step 8: Add `ToField`/`FromField` instances**
+
+  For `RoundedFileTime` (Int64 wrapper), `ServerEntityStatus` (Text via StrEncoding), `C.APublicAuthKey` (Binary via `encodePubKey`/`decodePubKey`). Check SMP's `QueueStore/Postgres.hs` for existing instances to import.
+
+- [ ] **Step 9: Wrap mutation operations in `uninterruptibleMask_`**
+
+  Operations that combine a DB write with a TVar update (e.g., `getFile` constructs `FileRec` with `newTVarIO`) must be wrapped in `E.uninterruptibleMask_` to prevent async exceptions from leaving inconsistent state. Follow SMP's `addQueue_`, `deleteStoreQueue` pattern.
+
+- [ ] **Step 10: Build**
+
+  Run: `cabal build -fserver_postgres`
+
+- [ ] **Step 11: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Store/Postgres.hs
+  git add src/Simplex/FileTransfer/Server/Store/Postgres.hs
+  git commit -m "feat(xftp): implement PostgresFileStore operations"
+  ```
+
+---
+
+## Task 8: Add INI config, Main.hs dispatch, startup validation
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Main.hs`
+- Modify: `src/Simplex/FileTransfer/Server/Env.hs`
+
+- [ ] **Step 1: Update `iniFileContent` in `Main.hs`**
+
+  Add to `[STORE_LOG]` section: `store_files: memory`, commented-out `db_connection`, `db_schema`, `db_pool_size`, `db_store_log` keys. Follow SMP's `optDisabled'` pattern for commented defaults.
+
+- [ ] **Step 2: Add `StartOptions` and `--confirm-migrations` flag**
+
+  ```haskell
+  data StartOptions = StartOptions
+    { confirmMigrations :: MigrationConfirmation
+    }
+  ```
+  Add to `Start` command parser with default `MCConsole`. Thread through to `runServer`.
+
+- [ ] **Step 3: Add store_files INI parsing and CPP-guarded Postgres dispatch**
+
+  In `runServer`: read `store_files` from INI (`fromRight "memory" $ lookupValue "STORE_LOG" "store_files" ini`). Add `"database"` branch (CPP-guarded) that constructs `PostgresFileStoreCfg` using `iniDBOptions ini defaultXFTPDBOpts` and `enableDbStoreLog'` pattern. Non-postgres build: `exitError`.
+
+- [ ] **Step 4: Add `XSCDatabase` branch in `newXFTPServerEnv` (`Env.hs`)**
+
+  CPP-guarded pattern match on `XSCDatabase dbCfg`: `newFileStore dbCfg`, `storeLog = Nothing`.
+
+- [ ] **Step 5: Add startup config validation**
+
+  Add `checkFileStoreMode` (CPP-guarded) before `run`: validate conflicting storeLog file + database mode, missing schema, etc. per design doc.
+
+- [ ] **Step 6: Build both ways**
+
+  Run: `cabal build && cabal build -fserver_postgres`
+
+- [ ] **Step 7: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Main.hs src/Simplex/FileTransfer/Server/Env.hs
+  git add src/Simplex/FileTransfer/Server/Main.hs src/Simplex/FileTransfer/Server/Env.hs
+  git commit -m "feat(xftp): add PostgreSQL INI config, store dispatch, startup validation"
+  ```
+
+---
+
+## Task 9: Add database import/export CLI commands
+
+**Files:**
+- Modify: `src/Simplex/FileTransfer/Server/Main.hs`
+
+- [ ] **Step 1: Add `Database` CLI command (CPP-guarded)**
+
+  Add `Database StoreCmd DBOpts` constructor to `CliCommand`. Add `database` subcommand parser with `import`/`export` subcommands + `dbOptsP defaultXFTPDBOpts`.
+
+- [ ] **Step 2: Implement `importFileStoreToDatabase`**
+
+  1. `confirmOrExit` with database details.
+  2. Create temporary `STMFileStore`, replay StoreLog via `readWriteFileStore`.
+  3. Create `PostgresFileStore` with `createSchema = True`, `confirmMigrations = MCYesUp`.
+  4. Batch-insert files using PostgreSQL COPY protocol. Progress every 10k.
+  5. Batch-insert recipients using COPY protocol.
+  6. Verify counts: `SELECT COUNT(*)` — warn on mismatch.
+  7. Rename StoreLog to `.bak`.
+  8. Report counts.
+
+- [ ] **Step 3: Implement `exportDatabaseToStoreLog`**
+
+  1. `confirmOrExit`. Fail if output file exists.
+  2. Create `PostgresFileStore` from config.
+  3. Open StoreLog for writing.
+  4. Fold over file records: write `AddFile` (with status), `AddRecipients`, `PutFile` per file.
+  5. Close StoreLog, report counts.
+
+- [ ] **Step 4: Build**
+
+  Run: `cabal build -fserver_postgres`
+
+- [ ] **Step 5: Format and commit**
+
+  ```bash
+  fourmolu -i src/Simplex/FileTransfer/Server/Main.hs
+  git add src/Simplex/FileTransfer/Server/Main.hs
+  git commit -m "feat(xftp): add database import/export CLI commands"
+  ```
+
+---
+
+## Task 10: Add Postgres tests
+
+**Files:**
+- Modify: `tests/XFTPClient.hs`
+- Modify: `tests/Test.hs`
+- Create: `tests/CoreTests/XFTPStoreTests.hs`
+
+- [ ] **Step 1: Add test fixtures in `tests/XFTPClient.hs`**
+
+  ```haskell
+  testXFTPStoreDBOpts :: DBOpts
+  testXFTPStoreDBOpts =
+    DBOpts
+      { connstr = "postgresql://test_xftp_server_user@/test_xftp_server_db",
+        schema = "xftp_server_test",
+        poolSize = 10,
+        createSchema = True
+      }
+  ```
+  Add `testXFTPDBConnectInfo :: ConnectInfo` matching the connection string.
+
+- [ ] **Step 2: Add Postgres server test group in `tests/Test.hs`**
+
+  CPP-guarded block that runs existing `xftpServerTests` with Postgres store config, wrapped in `postgressBracket testXFTPDBConnectInfo`. Parameterize `withXFTPServer` to accept store config if needed.
+
+- [ ] **Step 3: Create `tests/CoreTests/XFTPStoreTests.hs` — unit tests**
+
+  Test `PostgresFileStore` operations directly:
+  - `addFile` + `getFile SFSender` round-trip.
+  - `addFile` duplicate → `DUPLICATE_`.
+  - `getFile` nonexistent → `AUTH`.
+  - `setFilePath` + verify `WHERE file_path IS NULL` guard.
+  - `addRecipient` + `getFile SFRecipient` round-trip.
+  - `deleteFile` cascades recipients.
+  - `blockFile` + verify status.
+  - `expiredFiles` batch semantics.
+  - `getUsedStorage`, `getFileCount` correctness.
+
+- [ ] **Step 4: Add migration round-trip test**
+
+  Create `STMFileStore` with test data (files + recipients + blocked status) → export to StoreLog → import to Postgres → export back → compare StoreLog files byte-for-byte.
+
+- [ ] **Step 5: Build and run tests**
+
+  ```bash
+  cabal build -fserver_postgres test:simplexmq-test
+  cabal test --test-show-details=streaming --test-option=--match="/XFTP/" -fserver_postgres
+  ```
+
+- [ ] **Step 6: Format and commit**
+
+  ```bash
+  fourmolu -i tests/CoreTests/XFTPStoreTests.hs tests/XFTPClient.hs
+  git add tests/CoreTests/XFTPStoreTests.hs tests/XFTPClient.hs tests/Test.hs
+  git commit -m "test(xftp): add PostgreSQL backend tests"
+  ```
@@ -0,0 +1,126 @@
+# BBS+ Bindings for simplexmq
+
+Haskell FFI bindings to libbbs for BBS+ signatures. General-purpose - the module knows nothing about specific applications.
+
+## How BBS+ works
+
+BBS+ signs a fixed list of N messages. Each message is an arbitrary byte array. The signer signs all N messages at once with one signature.
+
+The holder of the signature can then generate a proof that selectively discloses some messages and hides others. The verifier learns the disclosed messages and confirms they were signed by the signer, but learns nothing about the hidden messages. Different proofs from the same signature are unlinkable.
+
+Key constraint: the total number of messages N is fixed at signing time. The verifier must know N. A proof generated from a 3-message signature cannot be verified as a 2-message proof.
+
+## Types
+
+```haskell
+newtype BBSSecretKey = BBSSecretKey ByteString  -- 32 bytes
+newtype BBSPublicKey = BBSPublicKey ByteString  -- 96 bytes (BLS12-381 G2 point)
+newtype BBSSignature = BBSSignature ByteString  -- 80 bytes
+newtype BBSProof = BBSProof ByteString          -- 272 + 32 * numUndisclosed bytes
+newtype BBSHeader = BBSHeader ByteString        -- always-disclosed context (e.g. protocol identifier)
+newtype BBSPresHeader = BBSPresHeader ByteString -- random nonce for proof unlinkability
+```
+
+All newtypes get StrEncoding (base64url), ToJSON/FromJSON (via strToJSON/strParseJSON), Eq, Show.
+
+## Functions
+
+```haskell
+bbsKeyGen :: IO (Either String BBSKeyPair)  -- BBSKeyPair = (BBSPublicKey, BBSSecretKey)
+
+-- pk is derived from sk internally, so it is not a parameter
+bbsSign
+  :: BBSSecretKey
+  -> BBSHeader            -- always-disclosed context
+  -> [ByteString]         -- all N messages
+  -> IO (Either String BBSSignature)
+
+-- C order: pk, signature, header, presentation_header, disclosed_indexes, messages
+bbsProofGen
+  :: BBSPublicKey
+  -> BBSSignature
+  -> BBSHeader            -- must match what was signed
+  -> BBSPresHeader        -- random nonce bound into the proof
+  -> [Int]                -- disclosed indexes (0-based)
+  -> [ByteString]         -- all N messages (needed internally, hidden ones not revealed in proof)
+  -> IO (Either String BBSProof)
+
+-- C order: pk, proof, header, presentation_header, disclosed_indexes, n, messages
+bbsProofVerify
+  :: BBSPublicKey
+  -> BBSProof
+  -> BBSHeader            -- must match what was signed
+  -> BBSPresHeader        -- must match what was used in bbsProofGen
+  -> [Int]                -- disclosed indexes
+  -> Int                  -- total message count N
+  -> [ByteString]         -- disclosed messages only
+  -> IO Bool
+```
+
+## How applications use it
+
+An application defines:
+- A message layout: which index means what
+- Which indexes are disclosed vs hidden
+- How to encode application values as ByteString messages
+
+### Badge example (in simplex-chat, not in this module)
+
+Message layout (always 3 messages):
+- Index 0: master secret (32 random bytes) - HIDDEN
+- Index 1: expiry (UTF-8 encoded timestamp string) - DISCLOSED
+- Index 2: badge type (UTF-8 encoded, e.g. "supporter") - DISCLOSED
+
+Signing (v2, on the server):
+```
+bbsSign sk header [ms, encodeUtf8 "2026-07-31", encodeUtf8 "supporter"]
+```
+
+Proof generation (v2, on the client):
+```
+bbsProofGen pk sig header presHeader [1, 2] [ms, encodeUtf8 "2026-07-31", encodeUtf8 "supporter"]
+```
+
+Proof verification (v1, on the recipient):
+```
+bbsProofVerify pk proof header presHeader 3 [1, 2] [encodeUtf8 "2026-07-31", encodeUtf8 "supporter"]
+```
+
+The recipient only sees the proof, presentationHeader, expiry string, and badge type string. They verify these were signed by the server (pk is hardcoded). They never see the master secret.
+
+Expiry is always present as a string. Monthly badges use a date like `"2026-07-31"`, lifetime badges use `"lifetime"`. BBS+ doesn't interpret the bytes - expiry semantics are the application's responsibility. This keeps the message count fixed at 3 for all badge types.
+
+## libbbs C API mapping
+
+```c
+int bbs_keygen_full(ciphersuite, sk, pk)
+int bbs_sign(ciphersuite, sk, pk, signature, header, header_len, n, messages, message_lens)
+int bbs_proof_gen(ciphersuite, pk, signature, proof, header, header_len, presentation_header, presentation_header_len, disclosed_indexes, disclosed_indexes_len, n, messages, message_lens)
+int bbs_proof_verify(ciphersuite, pk, proof, proof_len, header, header_len, presentation_header, presentation_header_len, disclosed_indexes, disclosed_indexes_len, n, messages, message_lens)
+```
+
+We use `bbs_sha256_ciphersuite`. The header parameter is exposed in all Haskell functions - the application decides what to put there. Tests use `"SimpleX"` as header.
+
+The `presentation_header` parameter is what we call `presentationHeader`.
+
+In `bbs_proof_verify`, the `n` parameter is the total number of messages (not the number of disclosed messages). The `messages` array contains only the disclosed messages, and `disclosed_indexes` maps each to its position in the original message list.
+
+## Build
+
+Submodules in cbits/:
+- `cbits/libbbs` - https://github.com/Fraunhofer-AISEC/libbbs
+- `cbits/blst` - https://github.com/supranational/blst (libbbs dependency)
+
+C sources in cabal: `cbits/blst/src/server.c`, `cbits/blst/build/assembly.S`, libbbs source files.
+Include dirs: `cbits/blst/bindings/`, `cbits/blst/src/`, `cbits/libbbs/include/`, `cbits/libbbs/src/`.
+C flags: `-D__BLST_PORTABLE__` for cross-CPU-generation compatibility.
+
+## Tests
+
+- Keygen produces keys of correct size
+- Sign + proofGen + proofVerify roundtrip succeeds
+- Tampered proof fails verification
+- Tampered disclosed message fails verification
+- Wrong public key fails verification
+- Two proofs from same credential with different nonces both verify
+- Proof size matches expected (272 + 32 * numUndisclosed)
@@ -0,0 +1,57 @@
+## Root cause: orphaned `Sub` entries in the service client's `subscriptions` map
+
+**The leak is service-specific and was introduced by PR #1667 "messaging services" (`f0b7a4be`).** A long-lived messaging-service connection accumulates per-queue `Sub` records in its `Client.subscriptions` map that are **never removed** when the associated queues are deleted or unassociated — only the counter is decremented. Over normal queue churn the map grows monotonically for the entire lifetime of the service connection.
+
+### The proof — an asymmetry between two handlers in `serverThread`
+
+Both individual queue subscriptions and service subscriptions store a `Sub` per queue in `Client.subscriptions` (= `clientSubs` for the SMP subscriber thread, wired at `Server.hs:189`). When a queue ends/is deleted, the two paths diverge:
+
+**Individual subscriber — entry IS removed** (`Server.hs:332`, `346`):
+```haskell
+CSAEndSub qId -> atomically (endSub c qId) >>= a unsub_   -- :332
+  ...
+endSub c qId = TM.lookupDelete qId (clientSubs c) >>= (removeWhenNoSubs c $>)  -- :346
+```
+
+**Service subscriber — entry is NOT removed** (`Server.hs:336-340`):
+```haskell
+CSAEndServiceSub qId -> atomically $ do
+  modifyTVar' (clientServiceSubs c) decrease   -- decrements serviceSubsCount
+  modifyTVar' totalServiceSubs decrease        -- decrements global count
+  where decrease = subtractServiceSubs (1, queueIdHash qId)
+  -- never touches (clientSubs c) — the Sub for qId stays forever
+```
+
+### Where the orphaned entries are added (both new in this PR)
+- `Server.hs:1860-1862` — on service subscribe (`SSUB`), one `Sub` inserted per queue that has a pending message.
+- `Server.hs:2039-2043` (`newServiceDeliverySub`) — on **every** `SEND` to a service-associated queue with no existing sub, a `Sub` is inserted into the service client's `subscriptions`. After delivery the thread state resets to `NoSub` (`:2069`) but the map entry remains as a "already delivering" marker (`:1856-1859`).
+
+### Why they leak
+The only places the service client's `subscriptions` map is cleared are:
+- `clientDisconnected` — `swapTVar subscriptions M.empty` (`Server.hs:1097`) — only on disconnect.
+- `CSADecreaseSubs` — `swapTVar (clientSubs c) M.empty` (`Server.hs:343`) — only on full service takeover by another connection.
+- `delQueueAndMsgs` — `TM.lookupDelete entId $ subscriptions clnt` (`Server.hs:2164`) — but `clnt` here is **the recipient deleting its own queue, not the service client**. The service's entry for that queue is reached only via the `CSDeleted → endServiceSub → CSAEndServiceSub` path (`Server.hs:306, 313, 336`), which decrements the counter but leaves the map entry.
+
+**Concrete scenario (fully traced):** Service `S` subscribes (`SSUB`) and stays connected for days. Recipient `R` owns service-associated queue `Q`. A `SEND` to `Q` inserts a `Sub` into `S.subscriptions[Q]` (`:2042`). `R` later deletes `Q` → `delQueueAndMsgs` runs on `R`'s connection, removes `Q` from `R.subscriptions`, decrements counters, enqueues `CSDeleted Q (Just S)` (`:2167`) → `serverThread` runs `CSAEndServiceSub Q` for `S` (`:336`), decrementing `S.serviceSubsCount` but **leaving `S.subscriptions[Q]` in place**. Net: one orphaned `Sub` (record + 2 TVars) per service-associated queue ever deleted/unassociated, never reclaimed until `S` disconnects. The logical counter `serviceSubsCount` correctly drops, so the map size diverges from the counter — making the leak invisible to the existing service-sub metric.
+
+### Verdict
+This is a deterministic, static-provable memory leak — no production logging needed to confirm the existence; the asymmetry between `CSAEndSub` (removes) and `CSAEndServiceSub` (doesn't) is the smoking gun. It is specific to messaging-service certificate clients, which is exactly the population added by the services/certificate PR.
+
+### Secondary findings (lower impact, same PR area, not the primary cause)
+- **`forkClient` register-after-fork race** (`Server.hs:1356-1359`): if the forked action's `finally` delete (`:1358`) runs before the parent's `IM.insert` (`:1359`), a `Weak ThreadId` of a dead thread is left in `endThreads` until disconnect. Pre-existing, tiny per-entry, but exercised far more by the PR's higher END/DELD volume.
+- **Wrong-client counter decrement** (`Server.hs:2166`): `delQueueAndMsgs` decrements `serviceSubsCount` of the *deleting* client, not the service; harmless for non-service deleters (floored at 0) but corrupts accounting if a service deletes its own queue.
+
+---
+
+### Recommended fix (mirror `endSub` in the service path)
+Make `CSAEndServiceSub` also delete the per-queue `Sub` and cancel its delivery thread, exactly as `CSAEndSub`/`endSub` do for individual subscribers. Roughly:
+
+```haskell
+CSAEndServiceSub qId -> do
+  s_ <- atomically $ do
+    modifyTVar' (clientServiceSubs c) decrease
+    modifyTVar' totalServiceSubs decrease
+    TM.lookupDelete qId (clientSubs c) <* removeWhenNoSubs c
+  forM_ unsub_ $ \unsub -> mapM_ unsub s_
+  where decrease = subtractServiceSubs (1, queueIdHash qId)
+```
@@ -0,0 +1,135 @@
+# Service RPC implementation plan
+
+RFC: [../rfcs/2026-07-11-service-rpc.md](../rfcs/2026-07-11-service-rpc.md)
+
+Depends on: [2026-07-12-address-dr-implementation.md](2026-07-12-address-dr-implementation.md). RPC establishes the double ratchet from the address exactly as address-DR does; this is the RPC layer on top of it.
+
+**Status: implemented and tested in this repo.** Service-side idempotency (single execution by request hash) is deferred. The `simplex-chat` integration is a separate repo.
+
+**Scope.** One request, one response — no continuation, no streaming.
+
+One DR-advertising contact address serves both flows: the owner branches per incoming request on the decrypted inner message — `AgentConnInfoReply` opens a connection (`REQ`), `AgentServiceRequest` answers an RPC (`SREQ`). A request gets exactly one reply, a response or a rejection; both are the single confirming message on the requester's reply queue Q_A, after which the ephemeral reply connection is torn down. Response and rejection are the same operation parameterized by the inner message (`AgentServiceResponse` payload vs `AgentRejection` reason) and outcome (the call returns the payload vs throws an agent error).
+
+## RPC messages
+
+No new outer envelope: the request reuses `AgentContactRequest` (tag `'A'`); the reply reuses `AgentConfirmation` (the only message on Q_A).
+
+Inner `AgentMessage` (ratchet-encrypted, parsed by `parseMessage`), siblings of `AgentConnInfoReply`:
+
+```haskell
+  | AgentServiceRequest (NonEmpty SMPQueueInfo) MsgBody  -- 'A': reply queue Q_A + opaque payload
+  | AgentServiceResponse MsgBody                         -- 'P': response payload (single, terminal)
+  | AgentRejection ByteString                            -- 'J': refusal reason (single, terminal)
+```
+
+`AgentServiceRequest` carries Q_A (as `AgentConnInfoReply` does); its constructor is the only thing that distinguishes `REQ` from `SREQ`. Delivery `msgType`: `AM_SRV_RESP` routes to `sendConfirmation` (the reply is the confirming first message on Q_A). `AM_SRV_REQ` is never stored — the request is sent synchronously inside `joinConnSrv'` via `sendInvitation`, so its arms in the delivery worker are unreachable and assert (`logError`).
+
+## Ratchet establishment — reuse of the address-DR flow
+
+`joinConnSrv'` takes `mkInner :: SMPQueueInfo -> AgentMessage`; `joinConnSrv` is the one-line wrapper passing `AgentConnInfoReply`. `sendServiceRequest'` passes `AgentServiceRequest`.
+
+**Request (client).** `serviceRequest_` fails fast with `A_SERVICE ASENotDRAddress` if the address carries no ratchet keys, then creates the client connection via `newConnToJoin` with `serviceRequestExpiresAt = Just (now + reqTimeout)` (the persisted per-request deadline), registers a one-shot `TMVar` in `serviceRequests`, sends the request, and blocks on the `TMVar` up to `reqTimeout`. The connection is `RcvConnection` (Q_A) with the send ratchet.
+
+**Request (service).** `smpContactRequest` decrypts `encConnInfo` and branches on the inner message; both branches call the same `storeInvitation` → `conn_invitations`, differing only in the kind column and event:
+
+- `AgentConnInfoReply` → `REQ` (`service_request = 0`).
+- `AgentServiceRequest _ payload` → `SREQ invId payload` (`service_request = 1`).
+
+Before storing, it **deduplicates** by the sender's ratchet-key hash (`checkRatchetKeyHashExists`/`addProcessedRatchetKeyHash`, the mechanism `newRatchetKey` uses): a redelivered/retried request reuses the same Q_A and the same `e2eSndParams`, so the hash matches and the duplicate is dropped — one invitation and one `REQ`/`SREQ` per request. Receive-time establishment on unauthenticated input — the address-DR abuse bound applies.
+
+**The reply (service).** `prepareReply` fetches the invitation, enforces the kind (`CMD PROHIBITED` on the wrong one), and rejects a stale request (`A_SERVICE ASETimeout` + delete) older than `serviceResponseTimeout`; then `newConnToAccept` + `startJoinInvitationDR` build the one-directional `SndQueue` to Q_A (no reply queue back), and `storeConfirmation` queues the inner message. `sendReplySync` secures Q_A, submits the message, and deletes the connection with wait-for-delivery — **deleting the connection on failure too** (`catchAllErrors`), so a failed secure/submit does not orphan it. `sendServiceReplyAsync` defers secure+deliver+delete to the `ICReplyDel` command (retried, survives a down server). `sendServiceReply`/`Async` and `replyRequest_` return the reply `ConnId` so the caller can correlate the `SENT` event on that throwaway connection.
+
+**The response (client).** The single `AgentConfirmation` on Q_A reaches `processConnInfo` (the `RcvConnection … New` branch). Dispatch is gated on `serviceRequestExpiresAt` and the kinds are mutually exclusive:
+
+- `AgentConnInfoReply` **only when `isNothing serviceRequestExpiresAt`** (a contact connection) → `processConf`.
+- `AgentServiceResponse` only when `isJust` → the request `TMVar` gets `Right payload`.
+- `AgentRejection` when `isJust` → `Left (A_SERVICE (ASERejected reason))`; when `isNothing` → contact `RJCT`.
+- anything else → `prohibited`.
+
+The `isNothing` guard on `AgentConnInfoReply` is a security boundary: without it a malicious service could send `AgentConnInfoReply` on an RPC reply queue and drive it into the contact-`CONF` path. `dispatchServiceReply` puts the result into the `serviceRequests` `TMVar`; a reply with no pending request (e.g. post-restart) is `ERR (A_SERVICE ASENoPendingRequest)`.
+
+## Rejection
+
+A rejection is `AgentRejection reason` — the same single confirming message on Q_A as a response.
+
+- **Kind guard.** `rejectContact` only on a contact invitation, `rejectServiceRequest`/`sendServiceReply` only on a request; wrong kind is `CMD PROHIBITED`. `rejectRequest_` enforces the kind **even on a `Nothing` (silent-drop) reject** — it fetches the invitation and checks before deleting, so `rejectContact … Nothing` cannot delete a service request (or vice versa).
+- `reject*` take `Maybe ByteString`: `Nothing` → delete the invitation, send nothing (the requester times out); `Just reason` → the reply path with `AgentRejection`.
+- Requester side: `AgentRejection` on a contact reply queue → `RJCT`; on an RPC reply queue → a thrown `A_SERVICE (ASERejected reason)`.
+
+## Reply connections and cleanup
+
+No reply-queue table and no new connection type.
+
+- **Requester reply queue** (`RcvConnection` on Q_A): `connections.service_request_expires_at` is non-null only here; it is the persisted request deadline, used both to gate CONF dispatch and to reap the connection. In-memory routing is `serviceRequests :: TMap ConnId (TMVar (Either AgentErrorType MsgBody))`.
+- **Timeout race.** The async `JOIN` worker holds `withConnLock c connId` around `joinConnSrv'`, and `serviceRequest_`'s cleanup holds the same lock around `TM.delete` + `deleteConnectionAsync'`. This serializes the send with the timeout teardown, so a timing-out call cannot delete the connection mid-send; after cleanup the worker's re-check of `serviceRequests` finds nothing and skips.
+- **Service reply connection** (`SndConnection` to Q_A): ephemeral — created, sends the one reply, deleted with wait-for-delivery in the same operation.
+- **Cleanup** (`cleanupManager`, `deleteExpiredServiceReqs`): `deleteExpiredServiceRequests` reaps unanswered `conn_invitations` (service side) older than `serviceResponseTimeout`; `getExpiredServiceConns` (`service_request_expires_at < now`) → `deleteConnectionsAsync'` reaps orphaned requester reply queues.
+
+## Database schema
+
+`M20260712_address_dr_rpc` (SQLite + PostgreSQL) creates `address_ratchet_keys` (address-DR) and adds:
+
+```sql
+ALTER TABLE conn_invitations ADD COLUMN service_request INTEGER NOT NULL DEFAULT 0; -- service side: 1 = RPC request
+ALTER TABLE connections ADD COLUMN service_request_expires_at TEXT;                 -- client side: request deadline; gating + cleanup (nullable)
+```
+
+The down migration drops the columns then the table/index. Schema dump tests pass (up, down, STRICT).
+
+## Agent API — `Simplex.Messaging.Agent`
+
+```haskell
+-- service: send the one response, return the reply ConnId, then tear the reply connection down.
+sendServiceReply      :: AgentClient -> NetworkRequestMode -> UserId -> InvitationId -> MsgBody -> AE ConnId
+sendServiceReplyAsync :: AgentClient -> ACorrId -> UserId -> InvitationId -> MsgBody -> AE ConnId
+
+-- refuse a request (Just reason = AgentRejection; Nothing = silent drop). PROHIBITED on wrong kind.
+rejectServiceRequest      :: AgentClient -> NetworkRequestMode -> UserId -> InvitationId -> Maybe ByteString -> AE ()
+rejectServiceRequestAsync :: AgentClient -> ACorrId -> UserId -> InvitationId -> Maybe ByteString -> AE ()
+rejectContact      :: AgentClient -> NetworkRequestMode -> UserId -> ConfirmationId -> Maybe ByteString -> AE ()
+rejectContactAsync :: AgentClient -> ACorrId -> UserId -> ConfirmationId -> Maybe ByteString -> AE ()
+
+-- client: establish the ratchet from the address, send the request, block on the reply TMVar up to the timeout
+-- (Nothing = serviceRequestTimeout; Just t overrides per request), returning the payload. Sync fails fast if the
+-- server is down; async enqueues a retried JOIN command that survives an outage.
+sendServiceRequest      :: AgentClient -> NetworkRequestMode -> UserId -> ConnectionRequestUri 'CMContact -> Maybe NominalDiffTime -> MsgBody -> AE MsgBody
+sendServiceRequestAsync :: AgentClient -> UserId -> ConnectionRequestUri 'CMContact -> Maybe NominalDiffTime -> MsgBody -> AE MsgBody
+```
+
+Both client calls share `serviceRequest_`; the async `JOIN` worker branches on the `JRServiceReq` command to send `AgentServiceRequest`. The call blocks on the `TMVar` and returns synchronously — no events, no correlation for the app.
+
+Events (`AEvent`, entity is the address connection):
+
+```haskell
+SREQ :: InvitationId -> MsgBody -> AEvent AEConn  -- payload = the request; mirrors REQ.
+RJCT :: ConnInfo -> AEvent AEConn                 -- contact-request rejection reason.
+```
+
+Errors (`SMPAgentError`):
+
+```haskell
+| A_SERVICE {serviceError :: AgentServiceError}
+
+data AgentServiceError
+  = ASERejected {rejectReason :: Text}  -- service refused (Text: JSON-serializable, UTF-8-decoded from the reason bytes)
+  | ASETimeout                          -- no reply within the timeout
+  | ASENoPendingRequest                 -- a reply arrived with no pending request (e.g. post-restart)
+  | ASENotDRAddress                     -- the target address advertises no ratchet keys (fail fast, no send)
+```
+
+Config (`AgentConfig`): `serviceRequestTimeout` (30 s, client wait, overridable per request) and `serviceResponseTimeout` (180 s, service reply window and cleanup TTL; must exceed `serviceRequestTimeout`).
+
+## Idempotency (deferred)
+
+Not built. When built, the service will key a request by hash and cache the one response for a retention period, answering a repeat from storage without reaching the bot — single execution over at-least-once delivery, with its own tables.
+
+## Tests
+
+In `FunctionalAPITests` (plus the encoding roundtrip in `ConnectionRequestTests`), passing with `-O0`:
+
+- Request → one response, sync (`sendServiceReply`) and async (`sendServiceReplyAsync`).
+- Request → rejection (`rejectServiceRequest (Just reason)` → thrown `A_SERVICE (ASERejected …)`).
+- Resilience: `server down → send → up → receive → down → reply → up → receive response`.
+- No regression: the contact rejection and DR-join suites still pass.
+
+The `simplex-chat` end-to-end tests (happy path, drop-when-off, non-DR fail-fast) live in that repo.
@@ -0,0 +1,279 @@
+# Establishing the double ratchet from address data - implementation plan
+
+RFC: [../rfcs/2026-07-12-address-pqdr-keys.md](../rfcs/2026-07-12-address-pqdr-keys.md)
+
+All references are to the current tree. Names of new constructors, fields, tables and functions are provisional.
+
+Goal: a contact address advertises the owner's X3DH parameters in link data; a requester establishes the double ratchet in its first message, so that message and the profile in it are under the ratchet with post-quantum protection. The change reuses the invitation/confirmation machinery, with the requester in the joiner role and the owner in the initiator role - opposite to today's contact flow, but every message and code path below is reused.
+
+Version: `addressDRVersion = VersionSMPA 8`, a plain agent-layer bump; `currentSMPAgentVersion` goes 7 → 8 (Agent/Protocol.hs:317-324). It gates the `AgentConfirmation.ratchetKeyId` field and the DR-from-address behavior. The receive-at-address path relies on ratchet-on-confirmation, already present since `ratchetOnConfSMPAgentVersion = 7` (Agent/Protocol.hs:317), so there is no cross-layer version dependency; the SMP and e2e-encryption versions are unchanged.
+
+Scope of this change: the **synchronous** DR handshake in join, gated on the address advertising `ratchetKeys`. `joinConnection`/`joinConn`/`joinConnSrv` gain an optional `Maybe AddressRatchetKeys` (the advertised `RcvE2ERatchetParamsUri` + `ratchetKeyId`), passed in from the link data the caller fetched at plan time (`LGET`); present → DR path (R2'/R3'), absent → the classic `AgentInvitation`. Chat wires that argument later (a chat change); the agent supports it now and tests pass it directly. Making the send **async** (worker retry, a "connecting" UX, the `CreatedConnLink` LGET-gate) is **deferred** - kept below under "Deferred" as future work, not part of this change.
+
+### Implementation status (as built; `lib:simplexmq` compiles)
+
+**Done** (compiles): version bump; `RatchetKeyId`/`AddressRatchetKeys` types + `Encoding`, `UserContactData.ratchetKeys` (appended, backward-compatible); `AgentConfirmation.ratchetKeyId` (version-gated encode/decode); `ContactRequest`/`DRRequest` sum with tagged `Encoding` + `cr_invitation` `ToField`/`FromField` (legacy-URI fallback); `address_ratchet_keys` table + `createAddressRatchetKeys`/`getAddressRatchetKeys` (SQLite + Postgres migrations `M20260712_address_dr`); join threading (`Maybe AddressRatchetKeys`); requester R2'/R3' (`joinAddressDR` + `sendConfirmationToAddress`); owner O1' dispatch, O2' `smpAddressConfirmation`, O3' (`acceptContact'` continue-ratchet branch), all three `connReq` readers (`acceptContact'`, `acceptContactAsync'` → `CMD PROHIBITED` for DR, `newConnToAccept` → shell from `drAgentVersion`/`drPQSupport`); requester R5' (`smpConfirmation` `RcvConnection … Nothing` branch, guarded on a ratchet existing); address-creation bundle generation (`mkAddressRatchetKeys`) wired into `createConnectionForLink'` (`IKUsePQ`-for-`SCMContact` prohibition lifted there).
+
+**Deltas from the plan discovered while building:**
+- **R5' emits `CONF` and reuses the allow step** (not auto-complete). The DR requester is a `RcvConnection` receiving the owner's reply - the same position as the classic contact requester, which goes `CONF` → `allowConnection'` → `connectReplyQueues` (msg 3). R5' mirrors that (differing only in that the ratchet already exists, so it `getRatchet` + `rcDecrypt` instead of building it), so the app supplies `ownConnInfo` for msg 3 at allow, exactly as today. No new storage.
+- **`DRRequest` carries `drAgentVersion` + `drPQSupport`** (Part 3): the sync accept creates the connection shell via `newConnToAccept`→`newConnToJoin` before O3', and there is no URI to derive the version/PQ from.
+- `cr_invitation` serialization is downgrade-safe: `CRInvitation` keeps the legacy URI (`strEncode`, byte-identical to before), so an older agent still reads classic invitations; `CRConfirmation` is JSON (`DRRequest` has manual `ToJSON`/`FromJSON`), told apart on read by the leading `{` (a URI never starts with it). JSON keeps `DRRequest` extensible. `SMPQueueInfo` gained a base64 `StrEncoding` + JSON (it only had `Encoding`) so it can sit in the JSON.
+- **DR is opt-in per address**: `createConnectionForLink'`/`createConnectionForLink` gain a `Maybe InitialKeys` DR parameter (separate from the existing connection-PQ `InitialKeys`) - `Nothing` = no DR (old behavior, existing callers), `Just ik` = advertise the bundle with `ik`. The `IKUsePQ`-for-`SCMContact` prohibition stays on the connection-PQ parameter and is lifted only for the DR bundle.
+
+**Test-matrix consequence of the version bump:** `currentSMPAgentVersion` 7 → 8 moves the version-matrix "prev" (`current − 1`) from v6 to v7. v7 ≥ `ratchetOnConfSMPAgentVersion (7)`, so a joiner/acceptor at "prev" now secures the send queue on confirmation - the `sqSecured` expectation for the prev variants in `testMatrix2`/`testMatrix2Stress`/`testBasicMatrix2` flips `False → True`. (Standard version-bump maintenance; the pre-`ratchetOnConf` unsecured path is now two versions back and no longer exercised by these matrices.)
+
+**Not yet done:** rotation (`rotateRatchetKeys`, Part 4), cleanup step (Part 4), the app-driven `LSET` upgrade API (Part 5), wiring the DR parameter into the non-prepared-link `newRcvConnSrv` path, DR-specific tests (Part 6), regenerating `agent_schema.sql` if a schema-consistency test requires it, and chat wiring (deferred by design).
+
+## Part 1 - the current contact-address handshake, step by step
+
+Requester Alice connects to owner Bob's contact address. Q_A is Alice's receive queue (Bob to Alice), Q_B is Bob's receive queue (Alice to Bob).
+
+Requester side, in `joinConnSrv … CRContactUri` (Agent.hs:1398-1428):
+
+- R1. `compatibleContactUri` (Agent.hs:1370) - version check, yields the address queue `SMPQueueInfo`.
+- R2. `mkJoinInvitation` (Agent.hs:1411): creates or reuses the receive queue Q_A; `getRatchetX3dhKeys` or `generateRcvE2EParams` produces Alice's Rcv X3DH parameters, stored by `createRatchetX3dhKeys` (Agent.hs:1424); builds `cReq = CRInvitationUri crData aliceRcvParams` (Agent.hs:1426).
+- R3. `sendInvitation` (Agent.hs:1408; Agent/Client.hs:1924-1934): sends `AgentInvitation {connReq = cReq, connInfo = aliceProfile}` to the address queue, per-queue encrypted with a fresh ephemeral key by `agentCbEncryptOnce` (Agent/Client.hs:1929-1934), unauthenticated. **`connInfo` (Alice's profile) is under the per-queue X25519 layer only - the gap this plan closes.**
+
+Owner side, receiving on the contact address:
+
+- O1. `processClientMsg` dispatch (Agent.hs:3185): state `(Nothing, Just e2ePubKey)`, `(PHEmpty, AgentInvitation {connReq, connInfo})` -> `smpInvitation` (Agent.hs:3186).
+- O2. `smpInvitation` (Agent.hs:3610): stores an `Invitation`, emits `REQ` with Alice's `connInfo`.
+- O3. `acceptContact'` (Agent.hs:1477): `getInvitation`, then `joinConn` with Alice's `connReq` (Agent.hs:1480).
+- O4. `joinConnSrv … CRInvitationUri` (Agent.hs:1383) -> `startJoinInvitation` (Agent.hs:1395).
+- O5. `startJoinInvitation` (Agent.hs:1310-1350): creates Bob's send queue to Q_A (`newSndQueue`, Agent.hs:1335); `createRatchet_` (Agent.hs:1343-1350) runs `generateSndE2EParams`, `pqX3dhSnd` against Alice's Rcv parameters, `initSndRatchet`, `createSndRatchet`.
+- O6. `secureConfirmQueue` (Agent.hs:1396, 3747-3765): `agentSecureSndQueue` secures Q_A with `SKEY` (Agent.hs:3749); `mkAgentConfirmation` (Agent.hs:3780-3785) calls `createReplyQueue` to create Bob's receive queue Q_B and returns `AgentConnInfoReply (Q_B :| []) bobInfo`; `mkConfirmation` ratchet-encrypts it and wraps `AgentConfirmation {e2eEncryption_ = Just bobSndParams, encConnInfo}`; `sendConfirmation` sends it to Q_A. This is confirmation #1.
+
+Requester side, receiving confirmation #1 on Q_A:
+
+- R4. dispatch (Agent.hs:3181-3183): state `(Nothing, Just e2ePubKey)`, `AgentConfirmation` -> `smpConfirmation`.
+- R5. `smpConfirmation`, initiating-party branch `RcvConnection … Just e2eEncryption` (Agent.hs:3405-3444): `getRatchetX3dhKeys`, `pqX3dhRcv` (Agent.hs:3408), `initRcvRatchet` (Agent.hs:3411), `createRatchet` (Agent.hs:3436), `setRcvQueueConfirmedE2E` (Agent.hs:3440); decrypts `AgentConnInfoReply` (Agent.hs:3420); `processConf` emits `CONF` (Agent.hs:3444).
+- R6. `allowConnection'` (Agent.hs:1467-1474): `acceptConfirmation`, then `ICAllowSecure` secures Q_A with Bob's sender key.
+- R7. `connectReplyQueues` (Agent.hs:3724-3737): `upgradeConn` creates Alice's send queue to Q_B; `agentSecureSndQueue` secures Q_B; `enqueueConfirmation … Nothing` (Agent.hs:3733) stores `AgentConnInfo aliceInfo` and sends `AgentConfirmation {e2eEncryption_ = Nothing, encConnInfo}` to Q_B. This is confirmation #2.
+
+Owner side, receiving confirmation #2 on Q_B:
+
+- O7. dispatch (Agent.hs:3182): `AgentConfirmation` -> `smpConfirmation`.
+- O8. `smpConfirmation`, accepting-party branch `DuplexConnection … Nothing` (Agent.hs:3447-3462): `agentRatchetDecrypt` with the established ratchet; `AgentConnInfo` -> `INFO` (Agent.hs:3452); `ICDuplexSecure` or `CON`.
+
+Completion is direct `CON` on `senderCanSecure` (SKEY) messaging-mode queues (the sender on `AgentConnInfo`, Agent.hs:2252; the receiver with no `senderKey`, Agent.hs:3459-3461); the separate `HELLO` via `helloMsg` (Agent.hs:3466) is the older non-`senderCanSecure` (duplexHandshake v2, in-band-securing) path.
+
+## Part 2 - the DR-from-address handshake, mapped to Part 1
+
+The address advertises Bob's Rcv X3DH parameters in link data (Part 3). Alice, when the address advertises them and versions are compatible, takes the joiner role; Bob takes the initiator role.
+
+Requester side - a new branch in `joinConnSrv … CRContactUri`, taken when the passed `Maybe AddressRatchetKeys` is present (the caller's plan-time `LGET`):
+
+- R2'. Replaces R2/R3. Read the passed bundle - `ratchetKeyId` and `e2eParams :: RcvE2ERatchetParamsUri 'C.X448` - and negotiate the concrete version with `compatibleVersion` against the client e2e range, as `compatibleInvitationUri` does (Agent.hs:1362-1368). Create the receive queue Q_A subscribed (`newRcvQueue` with `subMode`), messaging mode so Bob can secure it. Choose the requester's KEM with `replyKEM_ v ownerKem_ pqSup` (Ratchet.hs:839): if the bundle advertises a KEM (owner `IKUsePQ`) the requester `AcceptKEM` - a **double KEM**: it both encapsulates to the address KEM (ciphertext) and includes its own new KEM public key (`generateSndE2EParams` → `sntrup761Enc` + a fresh keypair, Ratchet.hs:433-435), so PQ is bidirectional from message 1; if the bundle has no KEM and the requester wants PQ, it `ProposeKEM` (its own key only, PQ from message 2 if the owner supports it). Run `generateSndE2EParams g v (replyKEM_ …)`, `pqX3dhSnd` against the negotiated parameters, `initSndRatchet`, `createSndRatchet` - the body of `createRatchet_` (Agent.hs:1343-1350), with parameters from the passed bundle rather than a received invitation.
+- R3'. Build `AgentConfirmation {e2eEncryption_ = Just aliceSndParams, ratchetKeyId = Just ratchetKeyId, encConnInfo = ratchetEncrypt(AgentConnInfoReply (Q_A :| []) aliceProfile)}` - the `mkAgentConfirmation`/`mkConfirmation` bodies (Agent.hs:3780-3765) with the reply queue being Alice's own Q_A. Send it to the address queue unauthenticated with `agentCbEncryptOnce`, one-shot (as `sendInvitation` sends, Agent/Client.hs:1929-1934) - **synchronous**, with the same send-failure UX as today's classic contact join. Nothing is stored: a retry (chat re-invokes the join → `mkJoinInvitation` reuses Q_A + keys, 1418) re-builds the confirmation, advancing the send ratchet, and the owner absorbs the advance - a **failed send** is skipped when the owner establishes the ratchet (`maxSkip = 512`, Ratchet.hs:988), and a **lost reply** carries the current content and updates the owner's request by `XContactId` (ContactRequest.hs:99-101, 269); both testable. The requester does **not** SKEY the address (`QMContact`, not `senderCanSecure`); rotation is handled because the passed params are the current advertised keys. **Alice's profile is now inside `encConnInfo`, under the ratchet.** Alice's connection is `RcvConnection` (Q_A) with a send ratchet, until she receives Q_B. This "New `RcvConnection` + `ratchets` row" is a new state (today a New `RcvConnection` holds x3dh keys but no ratchet - the classic initiator builds the ratchet only at R5, `createRatchet` Agent.hs:3436), and it composes: connection type is derived from queue rows alone while the `ratchets` table is keyed independently by `conn_id`, so subscription (Agent.hs:1551), `connectionStats` (2658), and `allowConnectionAsync'` (888) never read the ratchet for a `RcvConnection`; the only handshake reader on it is `smpConfirmation` (R5').
+
+### Deferred (future work): async delivery + connect UX
+
+The synchronous send above fails in the user's face on a lost reply (the same wart as today's classic contact join), even though the request may have been delivered. Making it async is a separate, later change, not part of this DR work:
+
+- Delivery cannot use the message-delivery worker: a `SndQueue` is unique per `(host, port, snd_id)` and belongs to one connection (schema PK), while a contact address is one queue that many connections send to, so no per-connection SndQueue to it can exist. It would go through the **async command worker**, keyed by `(connId, server)` (`getAsyncCmdWorker`, Agent.hs:1856-1858), which already retries the `JOIN` command (`tryMoveableCommand` → `retrySndOp`, 2016-2024); each retry re-runs `joinConnSrv` (re-build + ratchet advance, which the owner absorbs - above), so nothing is stored. (`joinConnSrvAsync` for `CRContactUri` is `CMD PROHIBITED` today, Agent.hs:1452, and the `JOIN` handler falls back to sync `joinConnSrv`, 1899-1902; the `TBC` at Agent.hs:1897 is about async *receive*-queue creation - Q_A - and is orthogonal.)
+- The async join returns "connecting" early and completes via the events chat already handles (`joinContact` sets `ConnJoined`; the DR requester emits `CONF` in R5' and the chat allows it, exactly as the classic contact requester, driving msg 3 → `CON`; a permanent send failure still surfaces as `ERR → ConnFailed`).
+- This needs a chat change: the join API takes a `CreatedConnLink` (full + short link), not the bare `ConnectionRequestUri` it takes today, so the agent can LGET-gate on the owner's server (a real reachability check) and verify the fetched `linkConnReq` equals the passed full link before reporting success. Used only for DR addresses (link data advertises `ratchetKeys`); old / non-DR addresses stay on the current sync path.
+
+Owner side - a new dispatch branch and a new receive handler:
+
+- O1'. In `processClientMsg` (Agent.hs:3176-3187), add a branch in state `(Nothing, Just e2ePubKey)`: an `AgentConfirmation` with `ratchetKeyId = Just _` **and** `e2eEncryption_ = Just _` on a `ContactConnection` -> `smpAddressConfirmation` (new). A `ratchetKeyId` without `e2eEncryption_` is ignored (it does not match this branch and falls through as a non-DR confirmation). It must be placed **before** the existing `(PHEmpty, AgentConfirmation) | senderCanSecure queueMode` case (Agent.hs:3182-3184), because a contact-address queue is `QMContact` (not `senderCanSecure`) and would otherwise fall into `prohibited "handshake: missing sender key"` (Agent.hs:3184). The address queue's `e2eDhSecret` stays `Nothing` (it is never set for a contact address - `smpInvitation` does not set it, Agent.hs:3609-3622), so every request is decrypted with its own ephemeral key via this `(Nothing, Just e2ePubKey)` path.
+- O2'. `smpAddressConfirmation` (new, modeled on `smpConfirmation` initiating branch, Agent.hs:3405-3444): select the private triple `(pk1, pk2, pKem)` by `ratchetKeyId` from `address_ratchet_keys`; `pqX3dhRcv pk1 pk2 pKem aliceSndParams`; `initRcvRatchet` with the address connection's stored `PQSupport` (`connPQEncryption` of the address `InitialKeys` - `On` for `IKUsePQ` and `IKPQOn`, `Off` for `IKPQOff`; this is what lets `IKPQOn` accept the requester's proposed KEM), combined with version compatibility as `smpConfirmation` derives `pqSupport'` (Agent.hs:3410); `rcDecrypt` of `encConnInfo` performs the first ratchet step, giving the ratchet its send side too (as it does for the initiator today), so the owner can later reply. Parse `AgentConnInfoReply (Q_A :| []) aliceProfile`. Store the request with `createInvitation` on the address connection (`contact_conn_id`), exactly as a classic invitation - except the request value is the `CRConfirmation` variant (Part 3) carrying the post-decrypt ratchet state and Q_A, and `recipient_conn_info` is `aliceProfile` - so **no connection or `ratchets` row is created at receive**, as with a classic invitation. Emit `REQ` with the `invitation_id`. A resend is not deduplicated: like a resent classic invitation it produces another `REQ` (the connect-UX fix for that is separate chat work). An unknown or expired `ratchetKeyId`, or a decryption failure: discard and acknowledge, as an undecryptable message is dropped today. This establishes ratchet state on unauthenticated input before the user accepts - see "Receive-time establishment, state, and abuse".
+- O3'. `acceptContact'` for a DR request - a new branch that continues the ratchet instead of `joinConn`. `getInvitation` returns the request; its `CRConfirmation` variant gives the stored ratchet state and Q_A. Create the connection now (as `joinConn` does for a classic invitation) and `createRatchet` (AgentStore.hs:1419) from the stored ratchet state. Reuse `mkAgentConfirmation` (Agent.hs:3780-3785) to create Bob's receive queue Q_B and return `AgentConnInfoReply (Q_B :| []) bobInfo`; create Bob's send queue to Q_A (`newSndQueue`, generating Bob's own sender key) and secure Q_A with `SKEY` using that key (`agentSecureSndQueue`, valid because Q_A is messaging mode) - the securing key is Bob's own, not taken from Alice's message; send the response to Q_A as `AgentConfirmation {e2eEncryption_ = Nothing, ratchetKeyId = Nothing, encConnInfo = ratchetEncrypt(AgentConnInfoReply (Q_B :| []) bobInfo)}` via `sendConfirmation` (`agentCbEncrypt` over Bob's send queue to Q_A, `PHEmpty` because Q_A is `senderCanSecure`) - exactly the current contact msg 2 path (Client.hs:1916), not `agentCbEncryptOnce`. The reply content is `AgentConnInfoReply`, not `AgentConnInfo`: it takes the `mkAgentConfirmation` path with `e2eEncryption_ = Nothing`, not the `enqueueConfirmation` path (which produces `AgentConnInfo`, Agent.hs:3789). `rejectContact'` deletes the `conn_invitations` row (the current behaviour), discarding the inline ratchet; no connection was created, so there is nothing else to clean up.
+
+Requester side, receiving the response on Q_A:
+
+- R5'. `smpConfirmation` needs a new branch `RcvConnection … Nothing` (today only `RcvConnection … Just` and `DuplexConnection … Nothing` exist, Agent.hs:3403-3447). It looks up the ratchet first (`getRatchet`) and, if there is none, falls through to `prohibited "conf: incorrect state"` - so a classic initiator (a New `RcvConnection` with x3dh keys but no ratchet) that receives a stray `Nothing`-confirmation keeps today's exact outcome; only a DR requester, which holds a send ratchet, takes the new path. Alice already holds the send ratchet, so `rcDecrypt` advances it and creates the receive side; parse `AgentConnInfoReply (Q_B :| []) bobInfo`. **This mirrors the classic contact requester exactly**: `setRcvQueueConfirmedE2E` on Q_A, `createRatchet` the advanced ratchet, store the reply as a `NewConfirmation`, and emit **`CONF`** - the app then calls `allowConnection'` (supplying `ownConnInfo` for msg 3), which drives `connectReplyQueues` (create Alice's send queue to Q_B, `SKEY`, upgrade to `DuplexConnection`, `enqueueConfirmation` the `AgentConnInfo` msg 3). Because Q_B is sender-securable, sending `AgentConnInfo` completes Alice with `CON` (Agent.hs:2252) - no `HELLO`. The only difference from the classic requester is that the ratchet is pre-built (from R2') rather than built from Bob's Snd params here, so there is no `CONF`-less auto-completion and no separate storage of Alice's own info.
+- R6'/completion. Unchanged from the current contact handshake, and modern (no `HELLO`). The exchange is three agent↔agent wire messages - Alice → address queue (msg 1), Bob → Q_A (msg 2, an `AgentConfirmation` carrying `AgentConnInfoReply` with Q_B), Alice → Q_B (msg 3, an `AgentConfirmation` carrying `AgentConnInfo`) - the same shape as the current contact flow, where msg 1 was `AgentInvitation`; here it is the ratchet-establishing `AgentConfirmation`. (`CON` is not a wire message - it is the agent→app event; `HELLO` and `AgentConnInfo` are the wire messages.) `HELLO` belongs to the older non-`senderCanSecure` path (duplexHandshake v2, before SKEY): there the confirmation secures the queue in-band (`PHConfirmation` carries the sender key, Client.hs:1918) and the receiver replies with `HELLO` (`ICDuplexSecure` → `enqueueDuplexHello`, Agent.hs:3457-3458). Both Q_A and Q_B here are messaging-mode - Q_A by R2', Q_B via `createReplyQueue` → `SCMInvitation` → `QMMessaging` (Agent.hs:1233,1458,3783) - so the sender secures with SKEY and sends `PHEmpty` (Client.hs:1918), the dispatch takes the `senderCanSecure` branch (Agent.hs:3182-3184), and each agent raises the `CON` app event locally off msg 3 - Bob on receiving it (`senderKey = Nothing`, Agent.hs:3459-3461), Alice on sending it (Agent.hs:2252) - with no separate `HELLO` wire message. (msg 2's `AgentConnInfoReply` only sets Q_A `Confirmed`, Agent.hs:2254.) Invitations are two messages because the initiator's queue is already in the link; a contact address needs three because Bob's receive queue Q_B is only delivered in msg 2. The third message no longer has a ratchet role: Bob's X3DH params are pre-published, so the agreement is complete once Bob receives msg 1 (in the current flow Bob's Snd params instead arrive in msg 2). msg 2 and msg 3 are queue setup - msg 2 delivers Q_B, msg 3 secures Q_B so Alice can send to Bob and signals Bob's `CON`; neither negotiates the ratchet. A one-directional exchange (the RPC) needs no Q_B and is two messages.
+
+Net code touch points: `joinConnSrv` (new requester branch), `processClientMsg` (new owner dispatch), `smpConfirmation` (new `RcvConnection … Nothing` branch and `AgentConnInfoReply` acceptance), `acceptContact'` (new continue-ratchet branch), a new `smpAddressConfirmation` reusing `createInvitation`/`getInvitation` with the sum request value, and the link data and storage of Part 3-4. `rejectContact'` is unchanged (it deletes the `conn_invitations` row either way).
+
+### Receive-time establishment, state, and abuse
+
+This is the substantive departure from the current flow. Today `smpInvitation` creates only a lightweight `NewInvitation` and emits `REQ` (Agent.hs:3618-3621); no connection or ratchet exists until the user accepts. For DR the request is under the ratchet, so to show the requester's profile in `REQ` the owner must decrypt it, which means establishing the ratchet at **receive**, before accept.
+
+Design decision (Q1): decrypt at receive. Both use cases need the request content at `REQ` - a person decides to accept from the profile, and a service bot needs the request payload to act. Deferring decryption to accept would make `REQ` contentless and does not fit the service case, so it is not done.
+
+Consequences:
+
+- No connection is created at receive, exactly as for a classic invitation. O2' stores the request with `createInvitation` on the address connection; the post-decrypt ratchet state and Q_A live inline in the `CRConfirmation` request value (`cr_invitation`). O3' (accept) creates the connection, `createRatchet` from the stored state, and adds Bob's queues, becoming a `DuplexConnection`; `rejectContact'` deletes the `conn_invitations` row.
+- Per incoming `AgentConfirmation` the owner does one `pqX3dhRcv` (three DH plus, with PQ, one `sntrup761` decapsulation) and one `rcDecrypt`, on unauthenticated input, and writes one `conn_invitations` row - more CPU than the current `NewInvitation`, the same order of state (no connection, no `ratchets` row until accept).
+
+Abuse (Q2): a contact address already accepts and processes unauthenticated invitations today, so this is a degree-worse version of an existing surface, not a new class. It is bounded by the address queue quota (an attacker fills it, the owner drains and acknowledges) and, optionally, by basic auth on the address (already supported for contact addresses, `optBasicAuth`). The per-request state is a single `conn_invitations` row - the same class as a classic contact request - so it is subject to the same limits and lifecycle, with no DR-specific dedup or TTL. Proof-of-work or a stricter gate can be added later; it is out of scope here and noted as a follow-up.
+
+`acceptContact'`/`rejectContact'` keep taking the `invitation_id` from `REQ` unchanged; the only difference is that `getInvitation` returns a request that is either a `CRInvitation` URI (current `joinConn` path, O3-O6) or a `CRConfirmation` (continue-ratchet path, O3'). Nothing in the `REQ`/accept/reject flow or the chat client changes - the change is contained in the agent.
+
+### The four communication layers, per message (verified against code)
+
+Layers, outermost (server-visible) first:
+
+- **L1 `ClientMsgEnvelope`** (Protocol.hs:1089), `PubHeader {phVersion, phE2ePubDhKey :: Maybe PublicKeyX25519}` (1096) - **this is where per-queue encryption is agreed** (not L2). `phE2ePubDhKey` is the sender's e2e DH public key; the recipient combines it with the queue's e2e private key: `(e2eDhSecret, e2ePubKey_) -> (Nothing, Just e2ePubKey) -> e2eDh = dh' e2ePubKey e2ePrivKey` (Agent.hs:3172-3178). `agentCbEncryptOnce` (Client.hs:2214) puts a **fresh ephemeral** pubkey (generated 2217, set 2223) - used when the sender has no send queue (the address queue), whose `e2eDhSecret` stays `Nothing`, so it decrypts every message with the per-message ephemeral. `agentCbEncrypt` (Client.hs:2203) puts the **send queue's persistent** e2e pubkey (`Just` on a confirmation, 2210); the recipient stores the secret via `setRcvQueueConfirmedE2E`, and *later* messages send `phE2ePubDhKey = Nothing` (`sendAgentMessage`, 2080).
+- **L2 `ClientMessage PrivHeader`** (Protocol.hs:1113), `PrivHeader = PHConfirmation APublicAuthKey | PHEmpty` (1115) - **queue securing / authorization, not encryption**. `PHConfirmation` carries the sender's AUTH key for in-band securing (v2, non-`senderCanSecure`); `PHEmpty` when the sender secured the queue with SKEY out-of-band. `PHEmpty` on every message here is about securing, and says nothing about encryption (that is L1). Set in `sendConfirmation` (Client.hs:1918), `sendInvitation` (1934), `sendAgentMessage` (2079).
+- **L3 `AgentMsgEnvelope`** (Agent/Protocol.hs:829, encoding 851) - outside the ratchet. `AgentConfirmation` ('C') carries `e2eEncryption_` (Snd X3DH params, agrees DR) + `encConnInfo`; `AgentInvitation` ('I') carries `connReq` (Rcv X3DH params) + plaintext `connInfo` (no DR); `AgentMsgEnvelope` ('M') carries `encAgentMessage`.
+- **L4 `AgentMessage`** (Agent/Protocol.hs:883, encoding 893) - inside the ratchet. `AgentConnInfo` ('I'), `AgentConnInfoReply` ('D', reply queues + info), `AgentMessage APrivHeader AMessage` ('M'; `AMessage` includes `HELLO`, Agent/Protocol.hs:1018-1020). **Absent when L3 is `AgentInvitation`** (that profile is per-queue-only - the gap this plan closes).
+
+Send routing: msg 1 (to address) → `sendInvitation` today / a new `agentCbEncryptOnce` confirmation send for DR; msg 2 → `secureConfirmQueue` → `sendConfirmation` (Agent.hs:3747); msg 3 → `connectReplyQueues` → `enqueueConfirmation` → delivery worker `AM_CONN_INFO` → `sendConfirmation` (Agent.hs:3733,3789,2183). `AM_CONN_INFO`/`AM_CONN_INFO_REPLY` both go through `sendConfirmation` (2183-2184); other `AMessage`s go through `sendAgentMessage` wrapping `AgentMsgEnvelope` 'M' (2192-2193).
+
+Current contact handshake (address does **not** advertise DR):
+
+| msg | L1 `PubHeader.phE2ePubDhKey` (per-queue enc) | L2 `PrivHeader` (securing) | L3 `AgentMsgEnvelope` | L4 `AgentMessage` |
+|---|---|---|---|---|
+| 1 Alice→addr | `Just` fresh ephemeral, `agentCbEncryptOnce` (Client.hs:1933,2223) | `PHEmpty` (1934) | `AgentInvitation` {connReq = Alice Rcv params, connInfo = profile} (Client.hs:1932) | — none (profile per-queue only) |
+| 2 Bob→Q_A | `Just` Bob's send-queue e2e pubkey, `agentCbEncrypt` (1920,2210) | `PHEmpty` [`senderCanSecure`] (1918) | `AgentConfirmation` {e2eEncryption_ = **Just Bob Snd params**, encConnInfo} (Agent.hs:3765) | `AgentConnInfoReply` (Q_B) bobInfo, DR-enc (Agent.hs:3785) |
+| 3 Alice→Q_B | `Just` Alice's send-queue e2e pubkey, `agentCbEncrypt` (1920,2210) | `PHEmpty` [`senderCanSecure`] (1918) | `AgentConfirmation` {e2eEncryption_ = **Nothing**, encConnInfo} (Agent.hs:3802) | `AgentConnInfo` aliceInfo, DR-enc (Agent.hs:3789) |
+
+New DR handshake (address advertises DR):
+
+| msg | L1 `PubHeader.phE2ePubDhKey` (per-queue enc) | L2 `PrivHeader` (securing) | L3 `AgentMsgEnvelope` | L4 `AgentMessage` |
+|---|---|---|---|---|
+| 1 Alice→addr | `Just` fresh ephemeral, `agentCbEncryptOnce` [same] | `PHEmpty` [same] | **`AgentConfirmation`** {e2eEncryption_ = **Just Alice Snd params**, **ratchetKeyId = Just**, encConnInfo} [was `AgentInvitation`] | **`AgentConnInfoReply`** (Q_A) aliceProfile, **DR-enc** [was plaintext connInfo] |
+| 2 Bob→Q_A | `Just` Bob's send-queue e2e pubkey, `agentCbEncrypt` [same] | `PHEmpty` [same] | `AgentConfirmation` {e2eEncryption_ = **Nothing**, ratchetKeyId = Nothing, encConnInfo} [was Just Bob Snd params] | `AgentConnInfoReply` (Q_B) bobInfo, DR-enc [same] |
+| 3 Alice→Q_B | `Just` Alice's send-queue e2e pubkey, `agentCbEncrypt` [same] | `PHEmpty` [same] | `AgentConfirmation` {e2eEncryption_ = Nothing, encConnInfo} [same] | `AgentConnInfo` aliceInfo, DR-enc [same] |
+
+Net difference: **only msg 1 and msg 2's L3/L4 change.** msg 1's L3 becomes `AgentConfirmation` (was `AgentInvitation`) carrying Alice's Snd params + `ratchetKeyId`, and the profile moves from plaintext L3 to DR-encrypted L4 (`AgentConnInfoReply`) - the whole point of the change. msg 2 drops `e2eEncryption_` (Bob no longer sends Snd params - the ratchet is agreed from msg 1). msg 3 is unchanged. L1 (per-queue encryption - each queue agrees its own secret via the sender's e2e pubkey in the `PubHeader` on the first message to it) and L2 (securing, `PHEmpty` because SKEY is used) are unchanged throughout; the DR change is entirely at L3/L4. The only new send code is msg 1 (an `AgentConfirmation` fired to the address with `agentCbEncryptOnce`, like `sendInvitation` but with a confirmation envelope).
+
+## Part 3 - types and link data
+
+### Fixed data - unchanged
+
+`FixedLinkData` (Protocol.hs:1824) is not touched. The double-ratchet keys go entirely in mutable data, so an existing address advertises them without a new link (the fixed data is hash-committed and cannot change). Fixed data keeps only `agentVRange`, `rootKey`, `linkConnReq`, `linkEntityId`.
+
+### Mutable data - ratchet keys bundle
+
+Appended to `UserContactData` (Protocol.hs:1840); the encoding stops at a trailing tail (Protocol.hs:1981), so earlier versions ignore it:
+
+```haskell
+newtype RatchetKeyId = RatchetKeyId ByteString -- opaque short id; one Encoding instance, shared below
+
+data AddressRatchetKeys = AddressRatchetKeys
+  { ratchetKeyId :: RatchetKeyId, -- identifies this bundle; changes on rotation, echoed in the request
+    e2eParams :: CR.RcvE2ERatchetParamsUri 'C.X448 -- version range + both X3DH keys + optional KEM
+  }
+instance Encoding AddressRatchetKeys where ... -- the key-bundle instance; both fields required
+
+data UserContactData = UserContactData
+  { direct :: Bool, owners :: [OwnerAuth], relays :: [ConnShortLink 'CMContact],
+    userData :: UserLinkData,
+    ratchetKeys :: Maybe AddressRatchetKeys -- whole bundle optional, one Encoding instance
+  }
+```
+
+`e2eParams` is the existing `RcvE2ERatchetParamsUri 'C.X448` (`E2ERatchetParamsUri VersionRangeE2E k1 k2 (Maybe (RKEMParams s))`, Ratchet.hs:282-286) - the same type a `CRInvitationUri` advertises - with `StrEncoding`/`Encoding` already defined (Ratchet.hs:302-374). There is no bespoke key type and no reconstruction: the requester negotiates the concrete version with `compatibleVersion` against its own e2e range, exactly as `compatibleInvitationUri` does for an invitation (Agent.hs:1362-1368), giving `RcvE2ERatchetParams` for `pqX3dhSnd`. The KEM is optional: `Nothing` gives an X448-only ratchet (as when `PQSupport` is off), `Just` a hybrid one, matching `generateRcvE2EParams`'s `PQSupport` gate (Ratchet.hs:439-445).
+
+The address-creation parameter is `InitialKeys` (Ratchet.hs:864) - the same 3-way choice as invitations, not a bare `PQSupport`. Currently `IKUsePQ` is prohibited for `SCMContact` (Agent.hs:990,1198) because a contact address carries no owner keys; this change lifts that prohibition. The bundle plays the published-contact-request role, so its KEM follows `initialPQEncryption False pqInitKeys` (Ratchet.hs:882) - exactly as the requester's contact request does today (Agent.hs:1422):
+
+- `IKUsePQ` - the bundle advertises the KEM; the requester encapsulates to it, so PQ from message 1.
+- `IKPQOn` (`IKLinkPQ PQSupportOn`) - the bundle is X448-only (no KEM advertised), but the owner's ratchet supports PQ (`connPQEncryption` = On, Ratchet.hs:888); the requester proposes its own KEM (R2'), so PQ from message 2.
+- `IKPQOff` (`IKLinkPQ PQSupportOff`) - X448-only, and the owner's ratchet does not support PQ even if the requester proposes it.
+
+Advertising the KEM adds ~1158 B to the rotated, widely-fetched link data, which is why `IKPQOn` exists (PQ one round later, without the size cost). The owner generates the bundle with `generateRcvE2EParams g v (initialPQEncryption False pqInitKeys)` (Ratchet.hs:439), stores the private triple `(pk1, pk2, pKem)` (Part 4), and advertises `e2eParams` by wrapping the public `E2ERatchetParams` in the address's e2e version range (`toVersionRangeT`; or `mkRcvE2ERatchetParams` from the stored privates, Ratchet.hs:412) - the same private-key shape `createRatchetX3dhKeys`/`getRatchetX3dhKeys` already store (AgentStore.hs:1362-1367). `ratchetKeys` is set by the agent when it signs mutable link data (`Crypto.ShortLink.encodeSignUserData`), not by the application.
+
+### Authentication of the advertised keys
+
+No signature is added on the keys: the mutable link data already signs them. `decryptLinkData` (Crypto/ShortLink.hs:106-114) verifies `sig2` over the mutable `UserContactData` by `rootKey`, so `ratchetKeys` is root-signed. This is the X3DH anti-substitution property: an SMP server cannot substitute the keys without forging the root signature. The signer is the root Ed25519 key (the address's signing identity); the X3DH keys are separate DH keys (X448, which cannot sign). A single owner signs address data ("we don't use multiple owners"), so the root signature alone is sufficient - no per-key signature. A malicious server can still serve an older but validly-signed `UserContactData` (rollback to a retired bundle); this is bounded by the retention window and by the ratchet advancing after the first message, and a signature does not prevent it. Inline ratchet params in a `CRInvitationUri` contact request are not in signed link data and remain unsigned - a separate change, out of scope here.
+
+### Request envelope
+
+`AgentConfirmation` (Protocol.hs:830-834) gains an optional `ratchetKeyId` - the `ratchetKeyId` of the `AddressRatchetKeys` bundle the requester used, so the owner selects the matching private keys:
+
+```haskell
+AgentConfirmation
+  { agentVersion :: VersionSMPA,
+    e2eEncryption_ :: Maybe (SndE2ERatchetParams 'C.X448), -- reused: Alice's Snd params in DR msg 1
+    ratchetKeyId :: Maybe RatchetKeyId,                    -- selects the owner's key generation
+    encConnInfo :: ByteString
+  }
+```
+
+`ratchetKeyId` is a separate optional selector (the shared `RatchetKeyId` newtype), not the bundle - the owner already holds the published public bundle and looks up its private keys by this id. It reuses the existing `e2eEncryption_` for Alice's Snd params rather than a new combined bundle; the minor cost is two correlated `Maybe`s (`ratchetKeyId = Just` is only meaningful with `e2eEncryption_ = Just`). **A `ratchetKeyId` with `e2eEncryption_ = Nothing` is ignored** - O2' requires both (there are no Snd params to run `pqX3dhRcv`), so such a message falls through to the current dispatch as if it had no `ratchetKeyId`.
+
+Encoding (extends Protocol.hs:853-866): from `addressDRVersion`, `smpEncode (agentVersion, 'C', e2eEncryption_, ratchetKeyId, Tail encConnInfo)`; `ratchetKeyId` is `Just` for an address-DR confirmation and `Nothing` for the current joiner-to-initiator and initiator-to-joiner confirmations; earlier versions omit the field entirely and use `smpEncode (agentVersion, 'C', e2eEncryption_, Tail encConnInfo)`. Parsing gates the field on `agentVersion`. `CRInvitationUri` is unchanged - a connection request URI holds Rcv parameters and must not hold Snd parameters.
+
+### Stored request - the invitation record
+
+The `conn_invitations` record stays; only the type of the stored request widens. From chat's point of view a DR request is still an invitation - it "contains a confirmation" instead of an invitation URI - so `REQ`, `acceptContact'`/`rejectContact'`, and the chat side are unchanged; the change is contained in the agent. The `NewInvitation`/`Invitation` request field (`cr_invitation`, stays `NOT NULL`) becomes a sum:
+
+```haskell
+data ContactRequest
+  = CRInvitation (ConnectionRequestUri 'CMInvitation) -- classic: joinConn on accept (O3-O6)
+  | CRConfirmation DRRequest                          -- DR: continue the ratchet on accept (O3')
+
+data DRRequest = DRRequest
+  { drRatchet :: RatchetX448,        -- post-decrypt receiving ratchet (with send side), stored inline
+    drReplyQueue :: SMPQueueInfo,    -- Q_A, where the owner replies
+    drAgentVersion :: VersionSMPA,   -- negotiated at receive; needed to build the connection shell at accept
+    drPQSupport :: PQSupport         -- the address's PQ setting for this connection
+  }
+```
+
+`recipient_conn_info` holds the profile in both cases. `getInvitation`/`createInvitation` carry `ContactRequest`; `acceptContact'` branches on the constructor. There is no dedup column: a resent request produces another `REQ`, exactly as a resent classic invitation does.
+
+`drAgentVersion`/`drPQSupport` are stored because the accept flow creates the connection **shell** through `newConnToAccept` → `newConnToJoin` (via `prepareConnectionToAccept`, called by chat's sync accept before `acceptContact'`, Internal.hs:914,925) and `newConnToJoin` today derives `connAgentVersion`/`pqSupport` from the `ConnectionRequestUri` (Agent.hs:1277-1293); a `CRConfirmation` has no URI, so the values negotiated at receive (O2') are stored and used to build the shell.
+
+Three readers of the widened `connReq` field (all via `getInvitation`) branch on the constructor:
+- `acceptContact'` (Agent.hs:1479, sync): `CRInvitation cr` → `joinConn … cr` (classic, unchanged); `CRConfirmation dr` → the O3' continue-ratchet path.
+- `newConnToAccept` (Agent.hs:1296, via `prepareConnectionToAccept`): `CRInvitation cr` → `newConnToJoin … cr` (unchanged); `CRConfirmation dr` → create the `NewConnection` shell from `drAgentVersion`/`drPQSupport` (`createNewConn`, generating the connId).
+- `acceptContactAsync'` (Agent.hs:900): `CRInvitation cr` → `joinConnAsync … cr` (unchanged); `CRConfirmation _` → `throwE $ CMD PROHIBITED` (async DR accept is deferred; DR requests accept synchronously). Chat's REQ/accept is unaffected either way - it only ever passes `invId`, never the `ContactRequest`, which stays internal to the agent.
+
+Storage: `cr_invitation`'s `ToField`/`FromField` encode `CRInvitation` as the legacy `strEncode` URI (unchanged from before, so the format is downgrade-safe) and `CRConfirmation` as JSON (`J.encode` of `DRRequest`). `FromField` peeks the first byte: `{` → JSON `CRConfirmation`, else `strDecode` → `CRInvitation` (a URI never starts with `{`). `DRRequest` uses manual `ToJSON`/`FromJSON` (extensible), and `SMPQueueInfo` gets a base64 `StrEncoding` + JSON to sit inside it. `smpInvitation` (Agent.hs:3618) wraps its `connReq` in `CRInvitation`; `smpAddressConfirmation` (O2') writes `CRConfirmation`.
+
+## Part 4 - key rotation (client-driven)
+
+Rotation is independent of the handshake above and is driven by the client app, not the agent. The agent never rotates on its own - it lacks the app's intent and the mutable link data (profile/badge and other short-link data). The app rotates by calling `setConnShortLink` with the rotate flag; the whole ratchet-keys bundle - both X448 keys and the KEM - is generated fresh each time.
+
+### Schema
+
+```sql
+-- one row per ratchet-keys generation for an address; the current generation plus the most recent retained ones.
+-- private side of the advertised RcvE2ERatchetParamsUri - same shape as the ratchets x3dh
+-- columns and createRatchetX3dhKeys (AgentStore.hs).
+CREATE TABLE address_ratchet_keys(
+  address_ratchet_key_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
+  ratchet_key_id BLOB NOT NULL,     -- the published id echoed by requests
+  x3dh_priv_key_1 BLOB NOT NULL,    -- X448
+  x3dh_priv_key_2 BLOB NOT NULL,    -- X448
+  pq_priv_kem BLOB,                 -- RcvPrivRKEMParams (sntrup761 keypair); NULL when PQ is off for this address
+  created_at TEXT NOT NULL DEFAULT(datetime('now'))
+);
+CREATE UNIQUE INDEX idx_address_ratchet_keys ON address_ratchet_keys(conn_id, ratchet_key_id);
+
+-- a DR request stays in conn_invitations with NO schema change: cr_invitation now holds a ContactRequest
+-- sum (an invitation URI or a confirmation carrying the post-decrypt ratchet + reply queue), so it stays
+-- NOT NULL - no nullable change, no new column on conn_invitations, no new table for the request.
+```
+
+`cr_invitation` stays `NOT NULL` - only its decoded value gains a variant (Part 3), so the invitations flow, `REQ`, and chat are unchanged; the only new storage is the `address_ratchet_keys` table. The link signing key is already on the address queue (`rcv_queues.link_priv_sig_key`, M20250322), so nothing is added there - rotation and retrofit re-sign mutable data with it. PostgreSQL mirrors this. Migration `M20260712_address_dr`.
+
+### Rotation logic
+
+The app rotates by calling `setConnShortLink` with the rotate flag; there is no automatic, agent-driven rotation. On rotation:
+
+1. `generateRcvE2EParams` for a fresh generation - two X448 keys, and an sntrup761 keypair only if PQ is on for this address - with a fresh `ratchetKeyId`.
+2. Recompute mutable link data with the new `AddressRatchetKeys` (the public `e2eParams`), re-sign with the root key (`encodeSignUserData`, key from `rcv_queues.link_priv_sig_key`), and `LSET` it to the address queue (`setConnShortLink` path).
+3. Insert the new `address_ratchet_keys` row (`x3dh_priv_key_1`, `x3dh_priv_key_2`, `pq_priv_kem`).
+
+### Retention
+
+Retention is count-based, not time-based: on each rotation `deleteOldAddressRatchetKeys` keeps the newest `keepAddressKeys` generations per address (default 3, ordered by `address_ratchet_key_id`) and deletes older ones. There is no `retired_at` column, no time window, and no `cleanupManager` step. A request that used a recently-retired bundle still decrypts while that generation is retained; how long a recorded first message stays decryptable after a compromise of the current private keys is therefore bounded by the retained-generation count and the app's rotation cadence (both app-controlled). Unaccepted DR request rows in `conn_invitations` are handled exactly like unaccepted classic invitation requests - no DR-specific cleanup (a DR request is one `conn_invitations` row, the same class of state as a classic contact request).
+
+## Part 5 - backward compatibility
+
+- A requester older than `addressDRVersion`, or an address without `ratchetKeys`, uses R2/R3 (`AgentInvitation`); the owner uses O1-O8. Unchanged.
+- The owner dispatches on the envelope: `AgentInvitation` -> `smpInvitation` (current); `AgentConfirmation` with `ratchetKeyId` on a `ContactConnection` -> `smpAddressConfirmation` (new). Both coexist.
+- `AgentConfirmation` without `ratchetKeyId` remains the current confirmation on established connections.
+- An existing address gains `ratchetKeys` via a new agent API (e.g. `updateContactAddressLink`) that the app calls with the mutable link data (profile/badge and any other short-link data): the agent generates the DR bundle if absent (the first `address_ratchet_keys` row and its stored private keys), adds `ratchetKeys` to `UserContactData`, re-signs with `rcv_queues.link_priv_sig_key`, and `LSET`s it. **Only mutable data changes - the address (link) is unchanged**, because the keys are in mutable, not fixed, data. Requesters that fetch the updated data use DR; older ones still use `AgentInvitation`. The agent does not do this on its own (it lacks the profile and the user's intent); the app drives it, combined with the full→short address migration.
+
+## Part 6 - tests
+
+- Encoding roundtrips: `UserContactData` with and without `ratchetKeys`, and with the KEM present and absent; `AgentConfirmation` with and without `ratchetKeyId`, across versions.
+- Address creation advertises `ratchetKeys` (the `RcvE2ERatchetParamsUri`); `decryptLinkData` (Crypto/ShortLink.hs:100) verifies signatures and the requester negotiates the advertised params to a concrete version, with and without the KEM.
+- Both PQ modes: an address whose bundle carries a KEM gives a hybrid ratchet (`pqEncryption` on); one without gives an X448-only ratchet.
+- End to end: a DR-advertising address; a new requester establishes the ratchet, sends its profile under it, owner emits `REQ`, accepts, both reach `CON`; assert the profile never travels under per-queue-only encryption; assert `pqEncryption` on.
+- Rotation and retrofit: request against the current bundle; against a just-retired bundle within the window still decrypts; against a bundle past the window is discarded and the requester times out; an address that adds `ratchetKeys` via `LSET` is then reached by DR while an old requester still uses `AgentInvitation`.
+- Backward compatibility: old requester against a DR address connects via `AgentInvitation`; new requester against a non-DR address falls back to `AgentInvitation`.
+
+## Part 7 - phases
+
+1. Link data: `AddressRatchetKeys` in `UserContactData` (reusing `RcvE2ERatchetParamsUri`), encoding, `encodeSignUserData`; `AgentConfirmation.ratchetKeyId`; address creation taking `InitialKeys` (lifting the `IKUsePQ`-for-`SCMContact` prohibition), generating (`generateRcvE2EParams`, KEM per `initialPQEncryption False`) and storing the first `address_ratchet_keys` row.
+2. Handshake: thread the optional `Maybe AddressRatchetKeys` through `joinConnection`/`joinConn`/`joinConnSrv` (present → DR branch, absent → classic); requester R2'/R3' (synchronous one-shot send); owner O1'/O2'/O3' storing the DR request as a `conn_invitations` row whose request value is the `CRConfirmation` variant; `smpConfirmation` `RcvConnection … Nothing` branch and `AgentConnInfoReply` acceptance; end-to-end connection with the profile under the ratchet. Tests pass `AddressRatchetKeys` directly (chat wiring is later work).
+3. Rotation and retrofit: schema migration, `rotateRatchetKeys`, retention window, cleanup step, app-driven `LSET` retrofit (with the full→short address migration), rotation/retrofit tests.
@@ -0,0 +1,59 @@
+# Signed service requests
+
+Optional Ed25519 signature on service RPC requests, constructed and verified in the agent (not the bot), bound to the request's double ratchet. Requests only — responses stay authenticated by the address/ratchet. Signing is optional; a bot decides whether to require it. The agent is stateless: the meaning of a signer key (identity, resource) is the bot's concern.
+
+## Wire — `Simplex.Messaging.Agent.Protocol`
+
+Extend the existing `'A'` inner message; `Maybe` absent = unsigned, so the unsigned path is unchanged:
+
+```haskell
+AgentServiceRequest (NonEmpty SMPQueueInfo) (Maybe RequestSignature) MsgBody
+
+data RequestSignature = RequestSignature C.PublicKeyEd25519 (C.Signature 'C.Ed25519)
+```
+
+## Binding
+
+```
+binding = sha3-256("SimpleXService" <> rcAD)
+sig     = Ed25519.sign(sk, binding <> payload)
+```
+The service recomputes `binding` from its own `rcAD` and verifies.
+
+- `rcAD` = the ratchet associated data (`Ratchet.rcAD`) — the shared connection security code: identical on both ratchets by construction (`pubKey(requester ephemeral) <> pubKey(service key)`), stable, and unique per request (fresh requester ephemeral). Already on the ratchet; nothing derived or stored.
+- sha3-256 here is not for uniformity or secrecy (both moot: the value is signed, not keyed, and only a ratchet holder can craft a valid request). It gives a canonical fixed-length, domain-tagged binding; the 32-byte fixed prefix also makes `binding <> payload` unambiguous.
+- Domain string `"SimpleXService"`: separates this signature from other uses of the signing key.
+- Not covered: reply queues (the AEAD protects them in transit; addresses may use redundant queues).
+- Anti-relay: a signature bound to one session's rcAD does not verify under another's (both parties' keys differ). Replay of the encrypted blob is handled separately by transport dedup.
+
+## Sign (requester) — `Simplex.Messaging.Agent`
+
+- `sendServiceRequest` / `sendServiceRequestAsync` gain a `Maybe` Ed25519 signing key.
+- `joinConnSrv'` DR path takes the ratchet straight from the `createRatchet_`/`getSndRatchet` line (both now yield `(RatchetX448, params)`) and computes `serviceReqBinding` from its `rcAD`; the `mkInner :: SMPQueueInfo -> ByteString -> AgentMessage` closure calls `signServiceReq signKey_ binding payload` — `RequestSignature pub (sign' pk (binding <> payload))` when a key is given, `Nothing` otherwise.
+- Async carries the key in `JRServiceReq {requestKey :: Maybe C.PrivateKeyEd25519}` (enabled `StrEncoding (PrivateKey Ed25519)`); the JOIN worker deserializes it and signs after building the ratchet.
+
+**Status:** implemented and tested in simplexmq-3 (sync + async); invalid signature → `A_SERVICE ASEBadSignature` (logs + `ERR` event), no invitation.
+
+## Verify (service) — `smpContactRequest`
+
+After `initRcvRatchet_` + decrypt, on `AgentServiceRequest (replyQueue :| _) sig_ payload`, one helper does the check:
+
+`verifyServiceReq rc payload sig_ :: Either String (Maybe C.PublicKeyEd25519)`
+- `Nothing` → `Right Nothing` (unsigned).
+- `Just (RequestSignature key sig)` → recompute `serviceReqBinding rc` and `C.verify' key sig (binding <> payload)`; `Right (Just key)` if valid, else `Left err`.
+
+Then:
+- `Right key_` → `storeInvitation … True` + `notify $ SREQ invId key_ payload`.
+- `Left err` → `logError` + `notify (ERR (AGENT (A_SERVICE ASEBadSignature)))`, no invitation.
+
+Dedup unchanged.
+
+## Event / API
+
+- `SREQ :: InvitationId -> Maybe C.PublicKeyEd25519 -> MsgBody -> AEvent AEConn`.
+- `StrEncoding (PrivateKey Ed25519)` enabled so a caller (e.g. via `JRServiceReq`) can carry the signing key.
+
+## Tests
+
+- `testSignedServiceRequest` (sync) + `testSignedServiceRequestAsync` — signed round-trip delivers the exact signer key on `SREQ` (`sigKey_ == Just signPub`).
+- Unsigned path unchanged (existing service tests carry `Nothing` for the new field).
@@ -0,0 +1,81 @@
+## Root cause: PRXY errors are attributed to the forwarding server instead of the destination relay
+
+When private routing is enabled and the destination relay is unreachable, the client reports
+**"Error connecting to forwarding server smp5.simplex.im"** — naming a preset server that the client
+connected to successfully. Retrying rotates to the next proxy (`getNextServer`, `Agent/Client.hs:689`)
+and produces the same message with a different preset server, so the destination server is never named
+and the failure looks like an outage of our own infrastructure.
+
+### Reproduction
+
+Connecting to a contact address on an unresolvable host (`simplex.server.home`, no DNS record):
+
+```
+-- private routing off (correct)
+BROKER {brokerAddress = "smp://VvXX…@simplex.server.home:5223",
+        brokerErr = NETWORK {networkError = NEConnectError {connectError = "…does not exist (Name or service not known)"}}}
+
+-- private routing on (misattributed)
+SMP {serverAddress = "smp://…@smp5.simplex.im,…onion",
+     smpErr = PROXY {proxyErr = BROKER {brokerErr = NETWORK {networkError = NEFailedError}}}}
+```
+
+### The asymmetry between the two proxied paths
+
+A server returns `PROXY (BROKER …)` only from `smpProxyError` (`Client.hs:804-815`), which is called
+exclusively where the proxy failed to reach the relay — `PRXY` (`Server.hs:1444`) and `PFWD`
+(`Server.hs:1466`). The error therefore *always* describes the proxy→relay hop. The two paths then
+diverge in how the agent wraps it:
+
+**PFWD — keeps both addresses** (`Agent/Client.hs:1183-1189`): the proxy's error arrives as
+`Left ProxyClientError` and is thrown as `PROXY {proxyServer, relayServer, proxyErr}`.
+
+**PRXY — drops the relay** (`Agent/Client.hs:713`): `connectSMPProxiedRelay` has no `Either` layer, so
+the error arrives as `PCEProtocolError` and `liftClient SMP` maps it to `SMP <proxyAddr> (PROXY …)`
+(`Agent/Client.hs:1244`). The destination address is discarded.
+
+Both clients read the second shape as a client→proxy failure and word it accordingly
+(`SimpleXAPI.kt:2692`, `ErrorAlert.swift:117`), which is never what it means.
+
+### Fix
+
+In `newProxiedRelay`, map proxy-reported `PROXY (BROKER …)` errors to the same shape `PFWD` already
+produces:
+
+```haskell
+proxyRelayError :: HostName -> ErrorType -> AgentErrorType
+proxyRelayError proxyHost = \case
+  e@(SMP.PROXY (SMP.BROKER _)) -> PROXY {proxyServer = protocolClientServer smp, relayServer = …destSrv, proxyErr = ProxyProtocolError e}
+  e -> SMP proxyHost e
+```
+
+`liftClient` applies this only to `PCEProtocolError`, so genuine client↔proxy failures (response
+timeout, network error, proxy transport version) still map to `BROKER <proxy> …` and remain attributed
+to the proxy. Both apps already render the resulting shape correctly, with no client change:
+*"Forwarding server smp5.simplex.im failed to connect to destination server simplex.server.home."*
+
+The guard is `BROKER` rather than every `ProxyError`, so the remap covers exactly the misattributed
+class and nothing else. `BASIC_AUTH` is deliberately excluded — the proxy returns it when proxying is
+disabled or the basic auth does not match (`Server.hs:1416-1420`), which is a client↔proxy fact and is
+correctly attributed today. `NO_SESSION` is returned only for `PFWD`. `PROTOCOL` describes the relay
+but is not rendered as a proxy-connection error by either client, so leaving it unchanged keeps the
+diff to the errors that actually produce a wrong message.
+
+### Blast radius
+
+- `temporaryAgentError` (`Agent/Client.hs:1572-1580`) and `serverHostError` (`:1594-1596`) already match
+  both shapes with the same helpers — retry and proxy-fallback behaviour is unchanged.
+- `clientServiceError` (`:1268-1273`) has no `PROXY`-shape twin for `BROKER NO_SERVICE`, but both ends
+  document that case as unreachable (`Client.hs:812`); left as is.
+- simplex-chat `Subscriber.hs:1819-1820` handles both shapes; send failures move from `SndErrProxy` to
+  `SndErrProxyRelay`, i.e. "Destination server error" rather than "Error" — also more accurate.
+- `SMP _ (PROXY _)` becomes unreachable, making `smpProxyErrorAlert` in both clients dead code. Removing
+  it is a follow-up in simplex-chat, not required by this change.
+
+### Verification
+
+- Reproduced before/after with a CLI built against this branch: the error now carries
+  `relayServer = "smp://VvXX…@simplex.server.home:5223"`, and the direct (non-proxied) path is
+  byte-identical to before.
+- `SMPProxyTests`: 45 examples, 0 failures — including `fails when fallback is prohibited` and both
+  retry tests, which exercise `newProxiedRelay` and the error classification.
@@ -0,0 +1,187 @@
+# Fast queue rotation — implementation plan
+
+Branch: ep/drop-agent-versions. RFC: ../rfcs/2026-08-09-fast-queue-rotation.md.
+
+Model: redundant delivery, no flip. `QADD` adds the new receive queue R'. From `QADD` until R' is
+secured the sender writes every message to both old and R' (double delivery, not a move); once R' is
+secured the sender writes new messages to R' only, while old delivers its already-scheduled tail and
+the `QEND` appended to it. `QEND` removes a named queue. The recipient drops duplicates (double
+ratchet), so the order and which queue delivers do not matter, as long as every message arrives on at
+least one queue. Rotation away from a dead server works because every message up to securing is
+scheduled on R' too.
+
+Roles: A initiates (its receive queue rotates; A receives on R'). B sends to A and secures R'.
+
+## Why redundant delivery removes the hard parts
+
+- No boundary, no drain, no last-message id. A never decides how much of old to read.
+- A dead old server loses nothing B still holds: every undelivered message is scheduled on R' as well.
+- A dead new server does not suspend delivery: old keeps delivering until R' is secured.
+- The double ratchet already drops duplicates (`AGENT A_DUPLICATE`) and tolerates bounded reordering,
+  and the delivery schema already writes one message to several send queues (`enqueueMessageB` +
+  `enqueueSavedMessageB`).
+
+## The one ordering constraint
+
+A must hold R''s secret before it reads any R' data message. A data message reaching R' before the
+confirmation is dropped as "no keys" (`processClientMsg`, `(Nothing, Nothing)` arm, line 3611), which
+loses it when old is dead. So the confirmation is the first message B sends on R'. R''s delivery
+worker does not start while R' is securing, so its accumulated rows cannot outrun the confirmation.
+`ICQSndSecure` sends the confirmation and only then starts the worker. This holds on restart too (see
+Worker gate).
+
+## New definitions
+
+Agent/Protocol.hs
+- Condition fast rotation on the existing `rpcAddressSMPAgentVersion` (v8, `Protocol.hs:322`).
+- New `AMessage` constructor `QEND SndQAddr` (tag `QE`), the address of the queue to remove. v8-only,
+  and only sent during fast rotation, so peers below v8 never parse it.
+- `SndSwitchStatus` constructors `SSSecuringQueue` (old, while R' secures) and `SSSendingQEND` (old,
+  after R' is secured — it drains its tail and `QEND` but takes no new messages).
+- `InternalCommand` constructor `ICQSndSecure SMP.SenderId`.
+
+No receive-side switch status, no boundary, no drain state.
+
+## Schema
+
+None. `SSSecuringQueue` uses `snd_queues.switch_status`; R' is secured into `rcv_queues.e2e_dh_secret`.
+No new columns, no migration.
+
+## Sender B
+
+### Dual scheduling from QADD
+
+`enqueueMessageB` writes a delivery row for the head send queue and for each `filter isActiveSndQ`
+tail queue (`Agent.hs:2345`). Adjust the selection two ways: additionally include a securing
+replacement queue on a v8 connection (`connAgentVersion cData >= rpcAddressSMPAgentVersion && status == New && isJust dbReplaceQueueId`),
+and exclude a terminating queue (`sndSwchStatus == Just SSSendingQEND`). The version guard keeps the
+slow path unchanged — there R' is also `New` with a replace reference during `QKEY`/`QUSE`, but it must
+not be dual-scheduled. `SSSendingQEND` is a fast-path-only status, so the exclusion never affects the
+slow path. The gate below is inert for the slow path anyway, since it never starts R''s worker while
+`New`.
+
+- `QADD` until R' secured: old is the head (active) and R' is the securing replacement, so every `SEND`
+  writes both rows. old delivers at once; R''s rows accumulate behind its gate.
+- R' secured: R' is the head (primary) and old is `SSSendingQEND` (excluded), so a `SEND` writes R'
+  only. old keeps its worker and delivers whatever was already scheduled on it, plus `QEND`.
+
+### Worker gate
+
+`submitPendingMsg` (`Agent.hs:2437`) and `resumeMsgDelivery` (`2421`) — the two `getDeliveryWorker`
+callers that start delivery — skip a queue with `status == New && isJust dbReplaceQueueId`, so neither
+a `SEND` nor startup starts R''s worker while it secures. Startup resumes delivery through
+`resumeMsgDelivery` (`resumeDelivery` line 1848, and `getAllSndQueuesForDelivery` line 1943), so R' is
+skipped there; `resumeAllCommands` (1883) resumes R''s `ICQSndSecure`, which secures R' and only then
+starts its worker.
+
+### Steps
+
+`qAddMsg` (fast branch, under the connection lock, `Agent.hs:3855`):
+- Add R' as the slow path does (line 3870): `addConnSndQueue (sq_) {primary = True, dbReplaceQueueId = Just old}`, `New`.
+- Duplicate **every** undelivered message on old to R': for each pending row on old
+  (`SELECT internal_id FROM snd_message_deliveries WHERE conn_id = ? AND snd_queue_id = old AND failed = 0`),
+  `createSndMsgDelivery db R' internalId`. This is the loss-prevention step: old's not-yet-sent
+  messages are duplicated onto R', so if old later fails they are already on R'. If old is already
+  down, nothing was sent and the whole backlog is duplicated.
+- `enqueueCommand (Just newSrv) (ICQSndSecure sndId)`; `setSndSwitchStatus SSSecuringQueue` on old
+  (where the slow path sets `SSSendingQKEY`, line 3874); notify `SWITCH QDSnd SPStarted`. old keeps
+  delivering; R''s worker is gated.
+
+`ICQSndSecure sId` (retryable, under `tryWithLock`):
+1. If old is already gone, a prior attempt finished; return. Otherwise find R' by `sId`.
+2. `secureSndQueue` (SKEY) R' — idempotent, since `sndPrivateKey` was persisted by `qAddMsg`
+   (`QueueStore/STM.hs:213`: same key → `Right ()`, different key → `AUTH`).
+3. Send the confirmation on R' (`sendConfirmation`; empty body, both peers already know each other;
+   `e2eEncryption_ = Nothing`, no ratchet step). It is the first message on R'.
+4. On success, in one transaction: `setSndQueueStatus R' Active` (the gate lifts), `setSndQueuePrimary R'`
+   (R' becomes the head; its replace reference is cleared), and `setSndSwitchStatus old (Just SSSendingQEND)`
+   (old takes no new messages but keeps its worker). Then `submitPendingMsg c R'` (the worker starts and
+   flushes the accumulated rows after the confirmation), `enqueueMessages [old, R'] (QEND oldAddr)`
+   (appended after old's tail, delivered on both), and notify `SWITCH QDSnd SPSecured`. From here a
+   `SEND` goes to R' only; old delivers its tail then `QEND` and is removed when `QEND` is sent.
+
+A temporary error retries from step 1; nothing is torn down. A permanent `AUTH` (should not occur, R'
+was secured with B's own key) leaves both queues and surfaces `A_QUEUE`.
+
+`QEND` sent — new `AM_QEND_` arm in `runSmpQueueMsgDelivery`, modelled on `AM_QTEST_` (`Agent.hs:2567`):
+on a successful send of `QEND addr`, remove the named send queue (`TM.delete` its worker,
+`deleteConnSndQueue addr`), make the remaining queue the sole primary (`setSndQueuePrimary`, which
+clears its `replace_snd_queue_id`), and notify `SWITCH QDSnd SPCompleted` (as `AM_QTEST_` does, line
+2591). This re-primary is a no-op on the send side — step 4 already made R' primary before `QEND` was
+enqueued. The handler is idempotent — a second `QEND` send finds the named queue already gone and does
+nothing. `QEND` is sent on both queues; removing old's send queue also drops any `QEND` still pending
+on old. The R' copy reliably removes old
+and reaches A even when old is dead; the old copy is best effort. Once old's send queue is gone, `SEND`
+schedules to R' only.
+
+## Recipient A
+
+A is subscribed to old (primary, `RSSendingQADD`) and R' (created at rotation start,
+`dbReplaceQueueId = old`).
+
+- **Confirmation on R'.** In `processClientMsg`, `(Nothing, Just e2ePubKey)` case, add an arm before the
+  `senderCanSecure` arm (`Agent.hs:3476`), guarded by `isJust (dbReplaceQueueId rq)`. In one
+  transaction: `setRcvQueueConfirmedE2E rq (C.dh' e2ePubKey e2ePrivKey) (min v phVer)` (secures R') and
+  `setRcvQueuePrimary R'` (clears R''s replace reference). Then `ack`, and notify `SWITCH QDRcv SPConfirmed`.
+  No conn-info processing, no ratchet step, no deferral. Redelivery is idempotent: R' now has `e2e_dh_secret`, so a re-sent
+  confirmation reaches the `(Just e2eDh, Just _)` arm (line 3608) and is acked — correct here, since
+  there is no backlog to hold.
+- **Data on R'.** With R''s replace reference cleared, a data message on R' takes the ordinary path
+  (`(_, dbReplaceQueueId=Nothing)`, line 3503) — no old-deletion, no `RSSendingQUSE` check. A copy
+  already read on old is dropped as `A_DUPLICATE`; a copy read first on R' advances the ratchet and
+  old's copy is then the duplicate.
+- **`QEND oldAddr` on either queue.** New `AMessage` handler (`qEndMsg`, a `qDuplex` handler like
+  `qAddMsg`): `findRQ oldAddr` the receive queue to remove. Mark it deleted (`setRcvQueueDeleted`, so
+  `getRcvQueuesByConnId_`'s `deleted = 0` filter excludes it at once and a restart does not resurrect
+  it) and `enqueueCommand (Just oldServer) (ICDeleteRcvQueue oldRcvId)` for the server `DEL` and record
+  removal — the async, crash-safe path `abortConnectionSwitch` uses, which resumes on restart and does
+  not block `QEND`, **not** the synchronous `deleteQueue` of `finalizeSwitch`, which would stall if old
+  is unreachable. `ICDeleteRcvQueue` (`Agent.hs:2224`) currently retries a temporary error forever;
+  bound it with the same persisted `rcv_queues.delete_errors`/`deleteErrorCount` mechanism `deleteQueueRec`
+  uses (2884): on a temporary error `incRcvDeleteErrors`, and at the limit `deleteConnRcvQueue` and
+  stop. The count is in the database, so the bound survives restarts, and its only other caller
+  (`abortConnectionSwitch'`, 2739) deletes an alive queue that succeeds well before the limit. `qEndMsg`
+  does **not** re-primary R' — the confirmation arm (above) owns R''s primary flag and replace
+  reference. `QEND` on old and the confirmation on R' travel on different queues with no order between
+  them, so `QEND` on old can be processed first (it sits only behind old's tail); re-primarying then
+  would clear R''s `dbReplaceQueueId` and the later confirmation would miss the rotation arm and never
+  secure R'. So `qEndMsg` only removes the named queue. Re-create the notification subscription
+  (`when enableNtfs $ sendNtfSubCommand ns (NSCCreate, [connId])`); notify
+  `SWITCH QDRcv SPCompleted`; `ackDel` the `QEND`. Received on both queues, the second finds it already
+  marked deleted and is a no-op.
+
+No drain, no boundary, no finalize command. Old is removed when `QEND` arrives, not by counting.
+
+## Abort / version
+
+- Fast rotation runs only when `connAgentVersion >= v8`; otherwise the `QKEY`/`QUSE` slow path runs
+  unchanged.
+- `canAbortRcvSwitch` (`Agent/Store.hs:210`) returns false for `RSSendingQADD` when `connAgentVersion >= v8`
+  (at v8 B always chooses fast, so A treats a sent `QADD` as committed). Its signature gains
+  `connAgentVersion`; both callers pass it from `cData` — `abortConnectionSwitch'` (2730) and
+  `rcvQueueInfo` in `connectionStats` (2976).
+
+## Losses and duplication
+
+- No boundary loss: the `QADD` step **duplicates** old's entire undelivered backlog onto R', and every
+  later message up to securing is scheduled on both queues, so if old fails it loses nothing B still
+  holds. The only messages old can strand are those its server already accepted but had not handed to
+  A — the ordinary store-and-forward risk, present whenever a server fails with unread messages, and
+  empty if old was already down (a down server accepted nothing).
+- Duplicates: the double ratchet drops them (`A_DUPLICATE`); `checkMsgIntegrity`'s `MsgDuplicate` is
+  only a flag, not the mechanism.
+- The 512 skip bound (`Crypto/Ratchet.hs:953`) does not bite on the rotation: each queue delivers in
+  order and every message B still holds is on R', so A reads a contiguous stream with only small
+  cross-queue reordering. A store-and-forward residual (above) is an ordinary loss, not introduced here.
+
+## Tests
+
+- new/new, old stopped right after `QADD`: rotation completes; all messages delivered on R'; old
+  removed by `QEND` on R'.
+- new/new, both alive: messages delivered on both, deduped; old removed by `QEND`.
+- new/old and old/new: fall back to the `QKEY`/`QUSE` path.
+- crash during securing: restart does not start R''s worker; `ICQSndSecure` resumes, secures R',
+  starts the worker, sends `QEND`.
+- `QEND` received on both queues: old removed once, the second receipt is a no-op.
+- `QEND` on old processed before the confirmation on R': R' still secures, because `qEndMsg` does not
+  clear R''s replace reference; rotation completes.
@@ -0,0 +1,152 @@
+# Server: batched SUB command processing
+
+Implementation plan for Part 1 of [RFC 2026-03-28-subscription-performance](../rfcs/2026-03-28-subscription-performance.md).
+
+## Current state
+
+When a batch of ~135 SUB commands arrives, the server already batches:
+- Queue record lookups (`getQueueRecs` in `receive`, Server.hs:1151)
+- Command verification (`verifyLoadedQueue`, Server.hs:1152)
+
+But command processing is per-command (`foldrM process` in `client`, Server.hs:1372-1375). Each SUB calls `subscribeQueueAndDeliver` which calls `tryPeekMsg` - one DB query per queue. For Postgres, that's ~135 individual `SELECT ... FROM messages WHERE recipient_id = ? ORDER BY message_id ASC LIMIT 1` queries per batch.
+
+## Goal
+
+Replace ~135 individual message peek queries with 1 batched query per batch. No protocol changes.
+
+## Implementation
+
+### Step 1: Add `tryPeekMsgs` to MsgStoreClass
+
+File: `src/Simplex/Messaging/Server/MsgStore/Types.hs`
+
+Add to `MsgStoreClass`:
+
+```haskell
+tryPeekMsgs :: s -> [StoreQueue s] -> ExceptT ErrorType IO (Map RecipientId Message)
+```
+
+Returns a map from recipient ID to earliest pending message for each queue that has one. Queues with no messages are absent from the map.
+
+### Step 2: Parameterize `deliver` to accept pre-fetched message
+
+File: `src/Simplex/Messaging/Server.hs`
+
+Currently `deliver` (inside `subscribeQueueAndDeliver`, line 1641) calls `tryPeekMsg ms q`. Add a parameter for an optional pre-fetched message:
+
+```haskell
+deliver :: Maybe Message -> (Bool, Maybe Sub) -> M s ResponseAndMessage
+deliver prefetchedMsg (hasSub, sub_) = do
+  stats <- asks serverStats
+  fmap (either ((,Nothing) . err) id) $ liftIO $ runExceptT $ do
+    msg_ <- maybe (tryPeekMsg ms q) (pure . Just) prefetchedMsg
+    ...
+```
+
+When `Nothing` is passed, falls back to individual `tryPeekMsg` (existing behavior). When `Just msg` is passed, uses it directly (batched path).
+
+### Step 3: Pre-fetch messages before the processing loop
+
+File: `src/Simplex/Messaging/Server.hs`
+
+Currently (lines 1372-1375):
+
+```haskell
+forever $
+  atomically (readTBQueue rcvQ)
+    >>= foldrM process ([], [])
+    >>= \(rs_, msgs) -> ...
+```
+
+Add a pre-fetch step before the existing loop:
+
+```haskell
+forever $ do
+  batch <- atomically (readTBQueue rcvQ)
+  msgMap <- prefetchMsgs batch
+  foldrM (process msgMap) ([], []) batch
+    >>= \(rs_, msgs) -> ...
+```
+
+`prefetchMsgs` scans the batch, collects queues from SUB commands that have a verified queue (`q_ = Just (q, _)`), calls `tryPeekMsgs` once, returns the map. For batches with no SUBs it returns an empty map (no DB call).
+
+`process` passes the looked-up message (or Nothing) through to `processCommand` and down to `deliver`.
+
+The `foldrM process` loop, `processCommand`, `subscribeQueueAndDeliver`, and all other command handlers stay structurally the same. Only `deliver` gains one parameter, and the `client` loop gains one pre-fetch call.
+
+### Step 4: Review
+
+Review the typeclass signature and server usage. Confirm the interface has the right shape before implementing store backends.
+
+### Step 5: Implement for each store backend
+
+#### Postgres
+
+File: `src/Simplex/Messaging/Server/MsgStore/Postgres.hs`
+
+Single query using `DISTINCT ON`:
+
+```sql
+SELECT DISTINCT ON (recipient_id)
+  recipient_id, msg_id, msg_ts, msg_quota, msg_ntf_flag, msg_body
+FROM messages
+WHERE recipient_id IN ?
+ORDER BY recipient_id, message_id ASC
+```
+
+Build `Map RecipientId Message` from results.
+
+#### STM
+
+File: `src/Simplex/Messaging/Server/MsgStore/STM.hs`
+
+Loop over queues, call `tryPeekMsg` for each, collect into map.
+
+#### Journal
+
+File: `src/Simplex/Messaging/Server/MsgStore/Journal.hs`
+
+Loop over queues, call `tryPeekMsg` for each, collect into map.
+
+### Step 6: Handle edge cases
+
+1. **Mixed batches**: `prefetchMsgs` collects only SUB queues. Non-SUB commands get Nothing for the pre-fetched message and process unchanged.
+
+2. **Already-subscribed queues**: Include in pre-fetch - `deliver` is called for re-SUBs too (delivers pending message).
+
+3. **Service subscriptions**: The pre-fetch doesn't care about service state. `sharedSubscribeQueue` handles service association in STM; message peek is the same.
+
+4. **Error queues**: Verification errors from `receive` are Left values in the batch. `prefetchMsgs` only looks at Right values with SUB commands.
+
+5. **Empty pre-fetch**: If batch has no SUBs (e.g., all ACKs), `prefetchMsgs` returns empty map, no DB call made.
+
+### Step 7: Batch other commands (future, not in scope)
+
+The same pattern (pre-fetch before loop, parameterize handler) can extend to:
+- `ACK` with `tryDelPeekMsg` - batch delete+peek
+- `GET` with `tryPeekMsg` - same map lookup
+
+Lower priority since these don't have the N-at-once pattern of subscriptions.
+
+## File changes summary
+
+| File | Change |
+|---|---|
+| `src/Simplex/Messaging/Server/MsgStore/Types.hs` | Add `tryPeekMsgs` to typeclass |
+| `src/Simplex/Messaging/Server/MsgStore/Postgres.hs` | Implement `tryPeekMsgs` with batch SQL |
+| `src/Simplex/Messaging/Server/MsgStore/STM.hs` | Implement `tryPeekMsgs` as loop |
+| `src/Simplex/Messaging/Server/MsgStore/Journal.hs` | Implement `tryPeekMsgs` as loop |
+| `src/Simplex/Messaging/Server.hs` | Add `prefetchMsgs`, parameterize `deliver` |
+
+## Testing
+
+1. Existing server tests must pass unchanged (correctness preserved).
+2. Add a test that subscribes a batch of queues (some with pending messages, some without) and verifies all get correct SOK + MSG responses.
+3. Prometheus metrics: existing `qSub` stat should still increment correctly.
+
+## Performance expectation
+
+For 300K queues across ~2200 batches:
+- Before: ~300K individual DB queries
+- After: ~2200 batched DB queries (one per batch of ~135)
+- ~136x reduction in DB round-trips
@@ -0,0 +1,126 @@
+# Server: batch queue service associations
+
+When a batch of SUB or NSUB commands arrives from a service client, each command that needs a new or removed service association calls `setQueueService` individually - one DB write per command. For 135 commands per batch, that's 135 individual `UPDATE msg_queues` queries.
+
+## Goal
+
+Reduce to at most 2 DB queries per batch (one for rcv associations, one for ntf associations), using `UPDATE ... RETURNING recipient_id` to identify which queues were actually updated.
+
+Also fuse message pre-fetch and association batching into a single batch preparation step with a clean contract.
+
+## Contract
+
+```haskell
+prepareBatch :: Maybe ServiceId -> NonEmpty (VerifiedTransmission s) -> M s (Either ErrorType (Map RecipientId (Maybe Message, Maybe (Either ErrorType ()))))
+```
+
+`Left e` = batch-level failure (message pre-fetch or association query failed entirely). All SUBs/NSUBs in the batch get this error.
+
+`Right map` = per-queue results as a tuple:
+- `Maybe Message` - pre-fetched message for SUB queues, `Nothing` for NSUB or no message
+- `Maybe (Either ErrorType ())` - association result. `Nothing` = no update needed. `Just (Right ())` = update succeeded. `Just (Left e)` = update failed for this queue.
+
+One map, one lookup per queue. `processCommand` passes both values to `subscribeQueueAndDeliver` / `subscribeNotifications` -> `sharedSubscribeQueue`.
+
+Queues not in the map (non-SUB/NSUB commands, failed verification) are not affected.
+
+## prepareBatch implementation
+
+One accumulating fold over the batch, collecting three lists:
+- `subMsgQs :: [StoreQueue s]` - SUB queues for message pre-fetch
+- `rcvAssocQs :: [StoreQueue s]` - SUB queues needing `rcv_service_id` update (`clntServiceId /= rcvServiceId qr`)
+- `ntfAssocQs :: [StoreQueue s]` - NSUB queues needing `ntf_service_id` update (`clntServiceId /= ntfServiceId` from `NtfCreds`)
+
+Classification reads from the already-loaded `QueueRec` in `VerifiedTransmission` - no extra DB query.
+
+Then three store calls (each skipped if its list is empty):
+1. `tryPeekMsgs ms subMsgQs` -> `Map RecipientId Message`
+2. `setRcvQueueServices (queueStore ms) clntServiceId rcvAssocQs` -> `Set RecipientId`
+3. `setNtfQueueServices (queueStore ms) clntServiceId ntfAssocQs` -> `Set RecipientId`
+
+Then one pass to merge results into `Map RecipientId (Maybe Message, Maybe (Either ErrorType ()))`:
+- For each SUB queue: `(M.lookup rId msgMap, assocResult rId rcvUpdated rcvAssocQs)`
+- For each NSUB queue: `(Nothing, assocResult rId ntfUpdated ntfAssocQs)`
+
+Where `assocResult rId updated assocQs` = if the queue was in `assocQs` (needed update), then `Just (Right ())` if `rId` is in `updated`, else `Just (Left AUTH)`. If not in `assocQs` (no update needed), `Nothing`.
+
+If any of the three calls fails entirely, return `Left e`.
+
+## Store interface
+
+Replace the polymorphic `setQueueServices` with two plain functions in `QueueStoreClass`:
+
+```haskell
+setRcvQueueServices :: s -> Maybe ServiceId -> [q] -> IO (Set RecipientId)
+setNtfQueueServices :: s -> Maybe ServiceId -> [q] -> IO (Set RecipientId)
+```
+
+No `SParty p` polymorphism. Each function knows its column.
+
+### Postgres implementation
+
+`setRcvQueueServices`:
+```sql
+UPDATE msg_queues SET rcv_service_id = ?
+WHERE recipient_id IN ? AND deleted_at IS NULL
+RETURNING recipient_id
+```
+
+`setNtfQueueServices`:
+```sql
+UPDATE msg_queues SET ntf_service_id = ?
+WHERE recipient_id IN ? AND notifier_id IS NOT NULL AND deleted_at IS NULL
+RETURNING recipient_id
+```
+
+After each batch query, for each queue in the returned set:
+1. Read QueueRec TVar, update with new serviceId
+2. Write store log entry
+
+### STM implementation
+
+Loop over queues, call existing per-item logic, collect succeeded `RecipientId`s into a Set.
+
+## Downstream changes in Server.hs
+
+### processCommand
+
+Gains one parameter: `Map RecipientId (Maybe Message, Maybe (Either ErrorType ()))`.
+
+SUB case: `M.lookup entId prepared` gives `Just (msg_, assocResult)` or `Nothing`. Pass both to `subscribeQueueAndDeliver`.
+
+NSUB case: `M.lookup entId prepared` gives `Just (Nothing, assocResult)` or `Nothing`. Pass `assocResult` to `subscribeNotifications`.
+
+Forwarded commands: pass `M.empty`.
+
+### subscribeQueueAndDeliver
+
+Takes `Maybe Message` and `Maybe (Either ErrorType ())` as before. No change in how it uses them.
+
+### sharedSubscribeQueue
+
+Takes `Maybe (Either ErrorType ())`. On paths needing association update:
+- `Just (Left e)` -> return error
+- `Just (Right ())` -> skip `setQueueService`, proceed with STM work
+- `Nothing` -> no update needed, proceed with existing logic
+
+## Implementation order (top-down)
+
+1. Define the `prepareBatch` contract and thread one map through `processCommand` -> `subscribeQueueAndDeliver` / `subscribeNotifications` -> `sharedSubscribeQueue` (Server.hs)
+2. Implement `prepareBatch` with the fold, three calls, and merge (Server.hs)
+3. Add `setRcvQueueServices` and `setNtfQueueServices` to `QueueStoreClass` (Types.hs)
+4. Implement for Postgres with batch `UPDATE ... RETURNING` (Postgres.hs)
+5. Implement for STM as loop (STM.hs)
+6. Implement for Journal as delegation (Journal.hs)
+
+At step 2, store functions can initially be stubs returning empty sets. Steps 3-6 fill in the real implementations.
+
+## Files changed
+
+| File | Change |
+|---|---|
+| `src/Simplex/Messaging/Server.hs` | `prepareBatch` with fold + merge; one map parameter through `processCommand` -> `subscribeQueueAndDeliver` / `subscribeNotifications` -> `sharedSubscribeQueue` |
+| `src/Simplex/Messaging/Server/QueueStore/Types.hs` | Add `setRcvQueueServices`, `setNtfQueueServices` to `QueueStoreClass` |
+| `src/Simplex/Messaging/Server/QueueStore/Postgres.hs` | Implement with batch `UPDATE ... RETURNING` + per-item TVar/log updates |
+| `src/Simplex/Messaging/Server/QueueStore/STM.hs` | Implement as loop |
+| `src/Simplex/Messaging/Server/MsgStore/Journal.hs` | Delegate to underlying store |
@@ -0,0 +1,455 @@
+# Server: SMP support for public namespaces
+
+> **⚠ Implementation diverged from this plan.** Six audit rounds reshaped the
+> original design. **The shipped code differs in several load-bearing ways:**
+>
+> - **Wire format**: `NameRecord` is now JSON (aeson), not the custom binary
+>   ABNF this plan documents. See `protocol/simplex-messaging.md` §Resolver
+>   commands and `src/Simplex/Messaging/Protocol.hs` ToJSON/FromJSON instances.
+> - **No cache**: the TTL + FIFO + byte-cap cache, in-flight coalescing,
+>   `psqueues` dep, and `cache_*` INI keys are all gone. Every RSLV becomes
+>   one `eth_call` bounded by `rpcMaxConcurrency` + `rpcTimeoutMs`. See
+>   `src/Simplex/Messaging/Server/Names.hs`.
+> - **No `allow_dangerous_colocation` flag**: the proxy co-location guard
+>   was demoted to a startup `logWarn` (the flag was always-on because
+>   `[PROXY]` has no enable toggle).
+> - **Module shape**: `Names/Resolver.hs` was merged into `Names.hs`; only
+>   `Names/Eth/RPC.hs` and `Names/Eth/SNRC.hs` remain as separate modules.
+> - **Test list**: of the 15 specs listed below, ~7 shipped; the rest were
+>   either superseded by the cache removal (CacheSpec) or deferred
+>   (ForwardedRslvSpec, MockRpcSpec, StartupGuardSpec, UrlValidationSpec,
+>   EipChecksumSpec).
+>
+> Sources of truth: `CHANGELOG.md` (release notes),
+> `protocol/simplex-messaging.md` §Resolver commands (wire format),
+> `src/Simplex/Messaging/Server/Names*.hs` (implementation). This file is
+> retained as historical context; do not treat it as a specification.
+
+Implementation plan for Part 2 of [RFC 2026-05-21-public-namespaces](https://github.com/simplex-chat/simplex-chat/blob/ep/namespace/docs/rfcs/2026-05-21-public-namespaces.md). Adds a forwarded-only `RSLV <lookup_key>` SMP command that returns `NAME <NameRecord>` read from the SNRC contract via a Reth+Nimbus JSON-RPC endpoint. Smp-server becomes name-capable by `[NAMES] enable: on`.
+
+Out of scope: `Simplex.Messaging.Client` API, agent-side resolution flow, `ServerRoles.names` in the agent, default-router list, reverse resolution, multicoin/text records, state proofs.
+
+## Architecture
+
+```mermaid
+sequenceDiagram
+  participant C as Client
+  participant P as Proxy (storage role)
+  participant N as Name server (names role)
+  participant E as Ethereum endpoint<br/>(Reth+Nimbus)
+
+  C ->> P: PFWD(enc(RSLV key))
+  P ->> N: RFWD(enc(RSLV key))
+  note over N: verifyTransmission True →<br/>vc SResolver (RSLV _) → VRVerified
+  N ->> N: cache lookup
+  alt cache miss
+    N ->> E: eth_call(SNRC, namehash(key))
+    E -->> N: ABI bytes
+    note over N: ABI decode + zero-owner check + cache insert
+  end
+  N -->> P: RFWD(enc(NAME rec | ERR AUTH))
+  P -->> C: PRES(enc(NAME rec | ERR AUTH))
+```
+
+RSLV is **forwarded-only** — direct RSLV is rejected `CMD PROHIBITED`. This preserves the RFC's two-server resolution: the name server sees the lookup key but never the client's IP, session, or identity.
+
+## Protocol
+
+Shared library: `src/Simplex/Messaging/Protocol.hs` and `src/Simplex/Messaging/Transport.hs`.
+
+**Version.** `Transport.hs:226`: `namesSMPVersion = VersionSMP 20`. Bump `currentClientSMPRelayVersion`, `currentServerSMPRelayVersion`, `proxiedSMPRelayVersion` to 20. Pre-v20 binaries lack the `RSLV_` tag; v20 binaries with sessions negotiated at v < 20 reject `RSLV_` at the parameter parser. The proxied-version bump 18 → 20 is safe (v19's `RecipientService`/`NotifierService` aren't in the forwarded whitelist; v18's `BLOCKED info` is already version-branched at `Protocol.hs:1943`).
+
+**Party kind.** Append `Resolver` to `Party` (line 335); add `SResolver` (line 349), `TestEquality` clause (line 361), `PartyI Resolver` (line 394). `queueParty SResolver = Nothing` (falls through line 412). `partyClientRole SResolver = Nothing`.
+
+**`RSLV` command.**
+
+```haskell
+RSLV :: LookupKey -> Command Resolver
+newtype LookupKey = LookupKey ByteString
+
+instance Encoding LookupKey where
+  smpEncode (LookupKey s) = smpEncode s
+  smpP = do
+    n <- lenP
+    when (n > 64) $ fail "LookupKey too large"
+    LookupKey <$> A.take n
+```
+
+Name-syntax validation is client-side per RFC; the server treats the key as opaque bytes. Tag `"RSLV"`, version guard inside `protocolP v (CT SResolver RSLV_)`: `| v >= namesSMPVersion -> Cmd SResolver . RSLV <$> _smpP`.
+
+**Testnet/mainnet selector**: how the `#testnet:name` namespace appears in `LookupKey` bytes is determined by the SNRC contract (Part 1) — confirm with Part 1 before merging.
+
+**`NAME` response.**
+
+```haskell
+NAME :: NameRecord -> BrokerMsg
+```
+
+Tag `"NAME"`. Symmetric version guards on encode (in `encodeProtocol v`) and decode (in `protocolP v NAME_`): `| v >= namesSMPVersion -> ...`. `NameRecord` has **no `Encoding` typeclass instance** — the typeclass cannot version-branch. Use top-level helpers `nameRecBytes :: VersionSMP -> NameRecord -> ByteString` and `parseNameRec :: VersionSMP -> Parser NameRecord`, mirroring the `IDS QIK` precedent at `Protocol.hs:1912–1979`.
+
+**`NameRecord` schema and wire layout.**
+
+```haskell
+data NameRecord = NameRecord
+  { nrDisplayName  :: Text                    -- ≤255 bytes UTF-8
+  , nrOwner        :: NameOwner               -- 20 raw bytes
+  , nrChannelLinks :: [NameLink]
+  , nrContactLinks :: [NameLink]
+  , nrAdminAddress :: Maybe Text
+  , nrAdminEmail   :: Maybe Text
+  , nrExpiry       :: Int64                   -- Unix seconds, ≥ 0
+  , nrIsTest       :: Bool
+  }
+
+newtype NameOwner = NameOwner ByteString   -- bare ctor NOT exported; smart ctor enforces length 20
+newtype NameLink  = NameLink  Text         -- bare ctor NOT exported; smart ctor enforces ≤1024 bytes
+
+unNameOwner :: NameOwner -> ByteString
+unNameOwner (NameOwner bs) = bs
+
+unNameLink :: NameLink -> Text
+unNameLink (NameLink t) = t
+```
+
+Field additions are gated by future SMP version bumps (matching the `IDS QIK` precedent at `Protocol.hs:1912–1979`) — no separate record-version field.
+
+| Field | Encoding | Max bytes |
+|---|---|---|
+| `nrDisplayName` | 1-byte length prefix + UTF-8 | 1 + 255 |
+| `nrOwner` | 20 raw bytes, no prefix | 20 |
+| `nrChannelLinks`, `nrContactLinks` | 1-byte count + per-element (Word16 BE len + UTF-8); combined cap **8 entries** across both lists | 1 + Σ(2 + ≤1024) |
+| `nrAdminAddress`, `nrAdminEmail` | `'0'` or `'1'` + (1-byte length + UTF-8 if `'1'`) | 1 + 1 + 255 |
+| `nrExpiry` | two big-endian `Word32` | 8 |
+| `nrIsTest` | `'T'` or `'F'` | 1 |
+
+`Encoding NameLink` reads the Word16 length **before** `A.take` allocates — going through the existing `Large` wrapper allows up to 65 535 bytes per element. There is no `Encoding [a]` instance — use `smpEncodeList` / `smpListP` / a bounded variant:
+
+```haskell
+smpListPUpTo :: Encoding a => Int -> Parser [a]
+smpListPUpTo cap = do
+  n <- lenP
+  when (n > cap) $ fail "list too long"
+  A.count n smpP
+
+parseNameRec _v = do
+  nrDisplayName  <- smpP
+  nrOwner        <- smpP
+  nrChannelLinks <- smpListPUpTo 8
+  nrContactLinks <- smpListPUpTo (8 - length nrChannelLinks)
+  nrAdminAddress <- smpP
+  nrAdminEmail   <- smpP
+  nrExpiry       <- smpP
+  when (nrExpiry < 0) $ fail "expiry must be non-negative"
+  nrIsTest       <- smpP
+  pure NameRecord{..}
+```
+
+Both list parsers fail at the count step before allocating; the second inherits the residual budget. Canonical encoding by construction: every primitive has exactly one valid byte form — two name servers reading the same SNRC state produce byte-identical responses.
+
+**Wire-size budget.** `paddedProxiedTLength = 16226` is the plaintext input to `cbEncrypt` (`Server.hs:2117`); `pad` reserves 2 bytes → framed transmission ≤ 16 224 bytes. Combined-link cap 8 yields max payload ≈ 9 050 bytes — generous margin.
+
+**Error semantics.** A single wire code: `ERR AUTH`. Per RFC, this collapses every failure (name not found, malformed key, names disabled, RPC unreachable, decode error, timeout). Resolver internally distinguishes the cause for stats only.
+
+**Forwarded-only access.** Direct RSLV is rejected with `CMD PROHIBITED`. The shape of `THAuthServer` alone cannot discriminate direct from forwarded (`Transport.hs:852` sets `sessSecret' = Just _` for every v6+ direct client too). An explicit `forwarded :: Bool` flag is threaded through `verifyTransmission` (see below).
+
+## Server changes
+
+All edits in `src/Simplex/Messaging/Server.hs`.
+
+**`forwarded :: Bool` plumbing.** Three signatures change:
+
+- `verifyTransmission :: Bool -> ...` (line 1233) — direct path passes `False` (lines 1152–1153), forwarded path passes `True` (line 2129).
+- `verifyLoadedQueue :: Bool -> ...` (line 1238) — receives the flag from `verifyTransmission` (lines 1235, 1240).
+- `verifyQueueTransmission :: Bool -> ...` (line 1244) — receives and uses the flag.
+
+New `vc` clauses inside `verifyQueueTransmission`:
+
+```haskell
+vc SResolver (RSLV _) | forwarded = VRVerified Nothing
+                      | otherwise = VRFailed (CMD PROHIBITED)
+vc SResolver _ = VRFailed (CMD PROHIBITED)   -- defensive catch-all
+```
+
+**Forwarded whitelist** (`Server.hs:2132`):
+
+```haskell
+Cmd SResolver (RSLV _) -> True
+```
+
+**`processCommand` branch** (alongside line 1481):
+
+```haskell
+Cmd SResolver (RSLV (LookupKey key)) -> do
+  st <- asks (rslvStats . serverStats)
+  incStat (rslvReqs st)
+  asks namesEnv >>= \case
+    Nothing -> incStat (rslvDisabled st)  $> response (corrId, NoEntity, ERR AUTH)
+    Just nenv -> liftIO (resolveName nenv key) >>= \case
+      Right rec     -> incStat (rslvSucc st)     $> response (corrId, NoEntity, NAME rec)
+      Left NotFound -> incStat (rslvNotFound st) $> response (corrId, NoEntity, ERR AUTH)
+      Left _        -> incStat (rslvEthErrs st)  $> response (corrId, NoEntity, ERR AUTH)
+```
+
+**Shutdown.** Add `closeNamesEnv :: NamesEnv -> IO ()` calling `closeManager`. Wire into `closeServer` (`Server.hs:247`):
+
+```haskell
+closeServer = do
+  asks (smpAgent . proxyAgent) >>= liftIO . closeSMPClientAgent
+  asks namesEnv >>= liftIO . mapM_ closeNamesEnv
+```
+
+In-flight `resolveName` calls during shutdown receive `ConnectionClosed` → `EthHttpErr` → masked-leader cleanup runs → waiters unblock with `ERR AUTH`.
+
+**`incStat` relocation.** Defined at `Server.hs:2220`, currently unexported. Move to `Server/Stats.hs` (one-line transplant + export) so `Resolver.hs` can use it.
+
+**Co-located proxy warning.** `newEnv` logs a startup warning whenever `allowSMPProxy = True` and `namesConfig = Just _`. RSLV is the first slow forwarded command; on a proxy host it can serialise other forwarded commands on the same proxy-relay session up to `rpcTimeoutMs` per cache miss. The warning is not a hard refusal because `[PROXY]` has no `enable: on/off` toggle — proxy is always on for every smp-server. `forkForwardedCmd` async dispatch is the longer-term fix, tracked as a follow-up; once the proxy role is gateable per-server, the warning can be tightened back to a refusal.
+
+## Resolver subtree
+
+New module tree at `src/Simplex/Messaging/Server/Names/`:
+
+| Module | Contents |
+|---|---|
+| `Names.hs` | Façade — re-exports `NamesConfig`, `NamesEnv`, `ResolveError`, `resolveName`, `newNamesEnv`, `closeNamesEnv`. |
+| `Names/Resolver.hs` | All types + cache + in-flight + `resolveName`. Helpers exported directly (no `.Internal` per codebase convention). **Test seam**: `NamesEnv` holds `ethCall` as a function value, so tests construct stubs via `newNamesEnvWith`. |
+| `Names/Eth/RPC.hs` | `EthRpcEnv`; `ethCallReal` via `http-client` + `withResponse` + `brReadSome rpcMaxResponseBytes`. JSON-RPC error / HTTP error split. `rpcMaxConcurrency` semaphore. `Authorization` header from `rpcAuth`. |
+| `Names/Eth/SNRC.hs` | `EthAddress`, Keccak-256 namehash via `crypton`'s `Crypto.Hash.Algorithms.Keccak_256` (mirroring `Crypto.hs:1023–1025` for SHA3), hand-rolled bounded Solidity ABI codec, `getRecord` with zero-owner detection. **Ethereum's Keccak ≠ NIST SHA3-256.** |
+
+**ABI codec invariants**, enforced before any allocation: `offset + 32 ≤ buf.length`; `offset + 32 + length ≤ buf.length`; `offset ≥ headEnd` (no backward jumps); every length ≤ per-field cap; `string[]` outer length × 32 ≤ buf.length; recursion depth ≤ 2; `uint256 → Int64` rejects if any high 24 bytes non-zero; UTF-8 via `decodeUtf8'` returns `EthDecodeErr`.
+
+**Zero-owner → `NotFound`**: ENS-style resolvers return zeroed records for non-existent names. After ABI decode, if `nrOwner == NameOwner (B.replicate 20 0)` return `Left NotFound`.
+
+**Errors.**
+
+```haskell
+data ResolveError = NotFound | EthHttpErr | EthRpcErr { rpcCode :: Int, rpcMessage :: Text }
+                  | EthDecodeErr | TimedOut
+```
+
+All collapse to `ERR AUTH`. `EthRpcErr` carries JSON-RPC `error` object — method-not-found (SNRC not deployed at `snrc_address`) is logged immediately on the first error after a recent success: `logError "NAMES: JSON-RPC error from endpoint — check snrc_address: <code> <message>"`. No automatic retry.
+
+**Cache.** TTL + FIFO eviction. `TVar (OrdPSQ LookupKey Word64 NameRecord, Int)` — priority = monotonic-ns at insert; the `Int` is running byte count. `cacheLookup` is one STM transaction (read, expiry-check, expired-delete-with-byte-decrement). `cacheInsert` is one STM transaction: while `size > cacheMaxEntries` OR `bytes + sizeOf(rec) > cacheMaxBytes`, `minView` to drop oldest, then `insert`. Byte counter prevents `100 000 × 9 KB ≈ 900 MB` worst-case blow-up.
+
+**Request coalescing** (async-exception safe via `E.mask`):
+
+```haskell
+resolveName env bs = do
+  let k = LookupKey bs
+  now <- getMonotonicTimeNSec
+  atomically (cacheLookup env k now) >>= \case
+    Just rec -> incStat (rslvCacheHits ...) $> Right rec
+    Nothing  -> do
+      incStat (rslvCacheMiss ...)
+      ticket <- atomically $ TM.lookup k (inflight env) >>= \case
+        Just mv -> pure (Waiter mv)
+        Nothing -> newEmptyTMVar >>= \mv -> TM.insert k mv (inflight env) $> Leader mv
+      case ticket of
+        Waiter mv -> atomically (readTMVar mv)
+        Leader mv -> E.mask $ \restore -> do
+          r <- restore (fetchOnceTimed env bs)
+                 `E.catch` \(e :: E.SomeException) -> pure (Left (mapEthErr e))
+          atomically $ putTMVar mv r >> TM.delete k (inflight env)
+          case r of Right rec -> atomically (cacheInsert env k now rec); Left _ -> pure ()
+          pure r
+
+fetchOnceTimed env bs =
+  System.Timeout.timeout (rpcTimeoutMs (config env) * 1000) (fetchOnce env bs) >>= \case
+    Just r  -> pure r
+    Nothing -> pure (Left TimedOut)
+```
+
+`E.mask` ensures `putTMVar + TM.delete` runs even on async exception; `fetchOnceTimed` runs under `restore` so it remains interruptible. Waiters always see a value; the in-flight TMap entry is always removed.
+
+`fetchOnce`, `mapEthErr`, `scrubUrl`, `cacheLookup`, `cacheInsert` are internal to `Resolver.hs`. `getMonotonicTimeNSec` from `GHC.Clock` — first monotonic-clock use in the codebase; clock-jump safe.
+
+**STM contention.** Cache hits are read-only `readTVar` — STM scales. Cache writes under sustained miss traffic can retry; `CacheSpec` asserts < 5% retry at 4 readers + 1 writer @ 1k RPS. If observed higher, swap `TVar` for `IORef` + `atomicModifyIORef'`.
+
+**Multicoin and text records** are not in `NameRecord`. If Part 1 contract returns them from `getRecord`, extend `NameRecord` and the wire-size budget. **Confirm with Part 1 author before implementing `Eth/SNRC.hs`.**
+
+## Configuration
+
+`ServerConfig` (`Env/STM.hs:142`) gains one field `namesConfig :: Maybe NamesConfig`. `Env` (`Env/STM.hs:261`) gains `namesEnv :: Maybe NamesEnv`. `newEnv` constructs it after `proxyAgent` (line 605) with the co-location guard.
+
+```haskell
+data NamesConfig = NamesConfig
+  { ethereumEndpoint     :: Text          -- http(s), no userinfo, explicit port required
+  , snrcAddress          :: NameOwner     -- 20 bytes
+  , rpcAuth              :: Maybe RpcAuth -- required when https & non-loopback host
+  , cacheSeconds         :: Int           -- 300
+  , cacheMaxEntries      :: Int           -- 100000
+  , cacheMaxBytes        :: Int           -- 67108864 (64 MB)
+  , rpcTimeoutMs         :: Int           -- 3000
+  , rpcMaxResponseBytes  :: Int           -- 262144 (256 KB)
+  , rpcMaxConcurrency    :: Int           -- 8
+  }
+
+data RpcAuth = AuthBearer Text | AuthBasic Text Text
+```
+
+INI parsing in `Server/Main.hs`:
+
+- `validateUrl` (using new `network-uri` dep): accepts only http(s), non-empty host, **explicit port** (rejects `http://localhost` defaulting to 80 while Reth is on 8545), no userinfo, no query/fragment. Rejects `https://...` without `rpc_auth` when host is non-loopback. On rejection: `logError` + `exitFailure`.
+- `parseEthAddr`: accepts `0x[0-9a-fA-F]{40}` and the same without `0x`. Mixed-case → verify EIP-55 checksum and reject mismatch (catches typos).
+- `parseRpcAuth`: reads optional `rpc_auth` key; format `bearer <token>` or `basic <user>:<pass>`.
+- `scrubUrl`: strips userinfo from all log lines mentioning the endpoint, including inside `mapEthErr`.
+- Transition-aware error logging: log immediately on first error after a recent success, then at most hourly while persisting + summary at every stats reset.
+
+Default INI template (`Server/Main/Init.hs`, after `[PROXY]`):
+
+```
+[NAMES]
+# Public-namespace resolution (SNRC on Ethereum).
+# Requires an Ethereum JSON-RPC endpoint (Reth+Nimbus). See deployment guide.
+# Cannot be combined with [PROXY] enable: on by default — see allow_dangerous_colocation.
+# Restart required to change settings.
+enable: off
+# Same-host:
+# ethereum_endpoint: http://127.0.0.1:8545
+# Central Reth via Caddy:
+# ethereum_endpoint: https://eth.simplex.chat:443
+# rpc_auth: basic <username>:<password>
+# snrc_address: 0x0000000000000000000000000000000000000000
+# cache_seconds: 300
+# cache_max_entries: 100000
+# cache_max_bytes: 67108864
+# rpc_timeout_ms: 3000
+# rpc_max_response_bytes: 262144
+# rpc_max_concurrency: 8
+# allow_dangerous_colocation: off
+```
+
+Upgrade from a pre-v6.6 INI: missing `[NAMES]` section → disabled. No operator action required.
+
+## Operator deployment
+
+Two supported topologies. smp-server is agnostic — only `ethereum_endpoint` changes.
+
+**Topology A (same-host)**: smp-server, Caddy (optional), Reth, Nimbus all on one box. `ethereum_endpoint: http://127.0.0.1:8545`.
+
+**Topology B (central Reth, N smp-server hosts — recommended for fleets)**: one operator runs one eth host with Reth+Nimbus behind Caddy on public HTTPS. Each smp-server has its own credential.
+
+```mermaid
+flowchart LR
+  subgraph eth-host
+    Caddy["Caddy<br/>(public :443, basic auth)"]
+    Reth["Reth<br/>(127.0.0.1:8545)"]
+    Nimbus["Nimbus"]
+    Caddy --> Reth
+    Nimbus -- Engine API (jwt.hex) --> Reth
+  end
+  subgraph smp-host-1
+    S1["smp-server #1"]
+  end
+  subgraph smp-host-N
+    SN["smp-server #N"]
+  end
+  S1 -- HTTPS + Authorization --> Caddy
+  SN -- HTTPS + Authorization --> Caddy
+  Reth <-- Ethereum p2p --> internet
+  Nimbus <-- beacon sync --> internet
+```
+
+Sharing one Reth across **multiple operators** is **not** supported — collapses the RFC's two-server resolution privacy.
+
+**Reth + Nimbus**: Reth (execution layer) holds Ethereum state on ~260 GB pruned NVMe; Nimbus (consensus light client) follows beacon-chain headers. Paired via Engine API on `127.0.0.1:8551` with a shared `jwt.hex`. Recommended Reth flags:
+
+```bash
+reth node \
+  --http.addr 127.0.0.1 \
+  --http.api eth \                     # only eth namespace
+  --rpc.gascap 50000000 \              # cap gas per eth_call
+  --rpc.max-response-size 5242880 \    # 5 MB
+  --http.corsdomain none \
+  --authrpc.jwtsecret /opt/eth/jwt.hex \
+  --authrpc.addr 127.0.0.1 --authrpc.port 8551
+```
+
+**Caddy + Let's Encrypt + Basic auth** (Topology B):
+
+```caddy
+eth.simplex.chat {
+  basicauth {
+    smp-server-1 $2a$14$<bcrypt-hash-1>
+    smp-server-2 $2a$14$<bcrypt-hash-2>
+  }
+  log { format filter { wrap json; fields { request>headers>Authorization delete } } }
+  reverse_proxy 127.0.0.1:8545
+}
+```
+
+Caddy auto-fetches Let's Encrypt cert. Each smp-server has its own credential; revoking one = delete the line. `Authorization` stripped from access logs. Port 80 needed for the ACME HTTP-01 challenge (use TLS-ALPN-01 or DNS-01 to drop it). The threat being defended against is DoS (SNRC state is public); mTLS would be overkill. WireGuard/Tailscale are alternative network-layer approaches — both compatible with the plan.
+
+**Capacity.** One Reth+Nimbus box handles a realistic operator fleet by 10–1000× margin. Per-smp-server peak RSLV ≈ 1700 RPS (pessimistic); cache hit rate ≥ 95% → ~85 RPS cache miss per smp-server; 10 smp-servers → ~850 RPS aggregate cache miss reaching Reth; Reth `eth_call` throughput on warm NVMe ≈ 1k–10k RPS. Sizing: 8 vCPU, 32 GB RAM, 1 TB NVMe is comfortable. Scale-out path: more Reth+Nimbus pairs, smp-servers round-robin or shard.
+
+## Implementation
+
+**Order**:
+
+1. Protocol: party/SParty/PartyI, RSLV+tag, NAME+tag, NameRecord + helpers, version constants in `Transport.hs`.
+2. `verifyTransmission`/`verifyLoadedQueue`/`verifyQueueTransmission` `forwarded :: Bool` flag + `vc SResolver` clauses.
+3. Forwarded whitelist + `processCommand` branch + `incStat` move to `Stats.hs`.
+4. Env plumbing: `Server/Env/STM.hs`, `Server/Main.hs` INI parse, `Server/Main/Init.hs` template.
+5. Resolver subtree: `Eth/SNRC.hs` → `Eth/RPC.hs` → `Resolver.hs`.
+6. `NameResolverStats` sub-record + CSV log + Prometheus `names =` block.
+7. Replace stub in (3) with real `resolveName`.
+8. Tests.
+9. `protocol/simplex-messaging.md`: header version line 1 (`19 → 20`), sentence at line 86, version-history list (lines 93–105) v20 entry, TOC (lines 25–68) "Resolver commands" subsection, new section with ABNF + byte layout + error semantics, "Router security requirements" paragraph about names-role outbound HTTP, cross-ref `Transport.hs:226`.
+10. `CHANGELOG.md`: v6.6 entry.
+
+**Cabal** (`simplexmq.cabal`): bump `version: 6.6.0.0`. Add to `if !flag(client_library)` block: `http-client >=0.7 && <0.8`, `http-client-tls >=0.3 && <0.4`, `network-uri >=2.6 && <2.7`, `psqueues >=0.2.7 && <0.3`. Expose 4 new `Server.Names.*` modules in the same block. `crypton` already provides `Keccak_256`.
+
+**Files changed**:
+
+| File | Change |
+|---|---|
+| `Protocol.hs` | Resolver party + RSLV/NAME tags + version guards; `NameRecord` + newtypes + smart ctors; `nameRecBytes`/`parseNameRec`/`smpListPUpTo` helpers (no Encoding NameRecord instance); `LookupKey` parser-side cap |
+| `Transport.hs` | `namesSMPVersion = 20`; bump current/proxied SMP versions |
+| `Server.hs` | Thread `forwarded :: Bool`; `vc SResolver` clauses; whitelist (2132); Resolver branch in `processCommand` (1481); `closeServer` calls `closeNamesEnv`; CSV log (579–618); **remove** local `incStat` |
+| `Server/Env/STM.hs` | `namesConfig` field; `namesEnv` field; `newEnv` constructs `NamesEnv` with co-location guard |
+| `Server/Main.hs` | `[NAMES]` parse: `validateUrl`/`parseEthAddr`/`parseRpcAuth`; `scrubUrl` in logs |
+| `Server/Main/Init.hs` | `[NAMES]` block in default INI |
+| `Server/Stats.hs` | `incStat` moved here + exported; `NameResolverStats` sub-record + helpers; `rslvStats` field |
+| `Server/Prometheus.hs` | `names =` metric block |
+| `Server/Names.hs` (new) | Façade re-exports |
+| `Server/Names/Resolver.hs` (new) | All resolver types + cache + coalescing + `fetchOnceTimed` + `newNamesEnv[With]` + `closeNamesEnv` |
+| `Server/Names/Eth/RPC.hs` (new) | `EthRpcEnv`, `ethCallReal` with bounded body + concurrency semaphore + `Authorization` header |
+| `Server/Names/Eth/SNRC.hs` (new) | `EthAddress`, Keccak namehash, bounded ABI (8 invariants), `getRecord` with zero-owner detection |
+| `simplexmq.cabal` | Bump `6.6.0.0`; 4 new deps + 4 new modules in `if !flag(client_library)` block |
+| `protocol/simplex-messaging.md` | Header version, version-history v20 entry, new "Resolver commands" section |
+| `CHANGELOG.md` | v6.6 entry |
+
+## Testing
+
+`tests/SMPNamesTests/` registered in `tests/Test.hs:112–151`. Build only when `client_library = False`.
+
+1. **ProtocolEncodingSpec** — `nameRecBytes` ↔ `parseNameRec` round-trip; oversized fields rejected at parse; combined-list cap 8 enforced; negative `nrExpiry` rejected; canonical encoding byte-stable.
+2. **MaxSizeSpec** — max `NameRecord` encodes ≤ ~9 KB; `encodeTransmission v ≤ paddedProxiedTLength - 2`; `cbEncrypt` succeeds.
+3. **CommandTagSpec** — `"RSLV"`/`"NAME"` parse; v < 20 sessions reject `RSLV_` at parameter parser.
+4. **ForwardedGateSpec** — direct RSLV → `CMD PROHIBITED`; forwarded RSLV reaches handler.
+5. **ForwardedRslvSpec** — RSLV wrapped in PFWD reaches the handler end-to-end. **Test infra cost**: first protocol-level PFWD test; budget for `runProxiedSmpCommand` helper performing `PRXY`/`PKEY`/`PFWD` manually.
+6. **CacheSpec** — hit avoids RPC; TTL expiry forces re-fetch; bytes cap evicts before entries cap on large records; concurrent same-key callers issue one RPC; leader exception → all waiters get `Left _`, TMap entry removed; leader async-cancel → cleanup STM still runs.
+7. **AbiSpec** — encode/decode against pinned fixtures (`tests/fixtures/snrc/`); QuickCheck fuzz on random buffers ≤ `rpcMaxResponseBytes` must never crash.
+8. **NamehashSpec** — Keccak-256 reference vectors; assert Keccak ≠ SHA3-256.
+9. **MockRpcSpec** — fake HTTP server; missing → `EthHttpErr`; slow → `TimedOut`; multi-GB body truncated → `EthDecodeErr`. `rpcAuth = AuthBasic` sends correct header.
+10. **Uint256OverflowSpec** — `expiry > Int64.maxBound` → `EthDecodeErr`.
+11. **ZeroOwnerSpec** — `owner = 0x000...000` → `NotFound`.
+12. **StartupGuardSpec** — `allowSMPProxy + names.enable` aborts; `allow_dangerous_colocation = on` starts with warning.
+13. **UrlValidationSpec** — userinfo/scheme/host/port edge cases; rejects `https://` without `rpc_auth` for non-loopback.
+14. **EipChecksumSpec** — `parseEthAddr` accepts lower/upper; verifies mixed-case checksum; rejects typos.
+15. **AbiBoundsSpec** — each of 8 ABI invariants triggers `EthDecodeErr` without crash/allocation blow-up.
+
+Integration against real Reth+Nimbus mainnet deferred to ops.
+
+## Threat model, scope, coordination
+
+| Actor | Can | Cannot |
+|---|---|---|
+| Name server | See lookup-key bytes; see query timing; see Eth endpoint URL (operator-self) | See client IP/session; correlate clients across queries |
+| Compromised Eth endpoint | Poison this server's cache for one TTL window; see every lookup key the server queries | Bypass two-server agreement (client-side, out of scope) |
+| Adversarial client (high-rate unique keys) | Cache-thrash DoS; fill `Manager` connection pool up to `managerConnCount = 8` | Bypass `rpcMaxResponseBytes` or `fetchOnceTimed` |
+| Adversarial proxy (slow inner RSLVs) | Block other forwarded commands on that proxy connection up to `rpcTimeoutMs` per miss | Affect other proxy connections |
+| Operator with footgun config (https no auth, public Eth RPC) | (rejected at startup, or operator-acknowledged data leak) | — |
+
+Mitigations: caching + coalescing + `rpcTimeoutMs` + `rpcMaxResponseBytes` + `rpcMaxConcurrency`; co-location refused at startup; URL validation; Caddy + auth in front of Reth; Reth's own gas/size caps. Timing side-channels (cache-hit vs miss latency) not mitigated — flagged for post-MVP. State proofs deferred to post-MVP per RFC.
+
+**Cross-repo coordination.** The `simplex-chat` `ep/namespace` branch currently contains only the RFC commit — no agent-side wire-format code yet. This plan's wire format is validated only by simplexmq's own tests until a matching agent PR lands (structurally weak — encoder/decoder bugs are mutually consistent with themselves). Coordinate with the agent-side implementer **before merging** on: exact `NameRecord` field order and types; `LookupKey` namespace-prefix convention; error-code semantics; Part 1 SNRC contract `getRecord` ABI surface.
@@ -5,13 +5,18 @@ sequenceDiagram
  participant S as Server<br>that has A's send queue<br>(B's receive queue)
  participant B as Bob

-  A ->> R': NEW: create new queue<br>(allow SKEY)
-  A ->> S: SEND: QADD (R'): send address<br>of the new queue(s)
+  A ->> R': NEW: create new queue (SKEY allowed)
+  A ->> S: SEND: QADD (R')
  S ->> B: MSG: QADD (R')
-  B ->> R': SKEY: secure new queue
-  B ->> R': SEND: QTEST
-  R' ->> A: MSG: QTEST
-  A ->> R: DEL: delete the old queue
-  B ->> R': SEND: send messages to the new queue
-  R' ->> A: MSG: receive messages from the new queue
-  
+  B ->> R: SEND: messages (also scheduled on R')
+  R ->> A: MSG: messages
+  B ->> R': SKEY: authorize B as sender
+  B ->> R': SEND: confirmation (establishes R' secret)
+  R' ->> A: MSG: confirmation (A secures R')
+  B ->> R': SEND: held copies (deduped), then new messages
+  R' ->> A: MSG: messages
+  B ->> R: SEND: remaining tail, then QEND
+  R ->> A: MSG: QEND
+  B ->> R': SEND: QEND
+  R' ->> A: MSG: QEND
+  A ->> R: DEL: delete the current queue
@@ -225,13 +225,13 @@ For encryption primitives, threat model, and detailed security analysis, see [Se

 SimpleX provides these security properties:

- **End-to-end encryption** with forward secrecy via double ratchet protocol, with optional post-quantum protection.
+- **End-to-end encryption** using Double Ratchet algorithm with forward secrecy and post-quantum cryptography.

 - **No shared identifiers** across connections — contacts cannot prove they communicate with the same user.

 - **Sender deniability** — neither routers nor recipients can cryptographically prove message origin.

- **Transport metadata protection** — fixed-size blocks, 2-hop onion routing, and connection isolation frustrate traffic correlation.
+- **Transport metadata protection** — fixed-size blocks, 2-hop onion routing, and optional connection isolation frustrate traffic correlation.

 - **Out-of-band key exchange** — connection requests passed outside the network protect against MITM attacks.

@@ -1,4 +1,4 @@
-Version 19, 2025-01-24
+Version 21, 2026-07-05

 # Simplex Messaging Protocol (SMP)

@@ -67,6 +67,9 @@ Version 19, 2025-01-24
    - [Queue deleted notification](#queue-deleted-notification)
    - [Error responses](#error-responses)
    - [OK response](#ok-response)
+  - [Resolver commands](#resolver-commands)
+    - [Resolve name command](#resolve-name-command)
+    - [Name record response](#name-record-response)
 - [Transport connection with the SMP router](#transport-connection-with-the-SMP-router)
  - [General transport protocol considerations](#general-transport-protocol-considerations)
  - [TLS transport encryption](#tls-transport-encryption)
@@ -83,7 +86,7 @@ It's designed with the focus on communication security and integrity, under the

 It is designed as a low level protocol for other application protocols to solve the problem of secure and private message transmission, making [MITM attack][1] very difficult at any part of the message transmission system.

-This document describes SMP protocol version 19. Versions 1-5 are discontinued. The version history:
+This document describes SMP protocol version 20. Versions 1-5 are discontinued. The version history:

 - v1: binary protocol encoding
 - v2: message flags (used to control notifications)
@@ -103,6 +106,8 @@ This document describes SMP protocol version 19. Versions 1-5 are discontinued.
 - v17: create notification credentials with NEW command
 - v18: support client notices in BLOCKED error
 - v19: service subscriptions to messages (SUBS, NSUBS, SOKS, ENDS, ALLS commands)
+- v20: public namespaces resolver (RSLV command, RNAME response) — direct or forwarded via PFWD
+- v21: server public information in handshake

 ## Introduction

@@ -424,6 +429,8 @@ Simplex messaging router implementations MUST NOT create, store or send to any o

 - Any other information that may compromise privacy or [forward secrecy][4] of communication between clients using simplex messaging routers (the routers cannot compromise forward secrecy of any application layer protocol, such as double ratchet).

+Routers with the names role make outbound HTTP calls to a backing resolver service (the reference implementation is `scripts/resolver/snrc-resolve.py`, which in turn makes JSON-RPC calls to an Ethereum endpoint) to read `NameRecord` data; the lookup key reaches that resolver and its upstream RPC endpoint. Operators MUST run both the resolver process and its upstream RPC endpoint themselves (loopback Reth + Nimbus, or a self-hosted central deployment) — sharing them across multiple operators collapses the two-server privacy property because the resolver / RPC operator would see every lookup key across all of them. The names role and the SMP-proxy role MUST NOT be enabled on the same router by default: a client forwarding `RSLV` through a proxy that is also the names router would expose both its connection and the lookup key to one operator, collapsing the two-server privacy property. (Resolution itself runs on a forked thread, so a slow `RSLV` does not serialise other forwarded commands on the session.)
+
 ## Message delivery notifications

 Supporting message delivery while the client mobile app is not running requires sending push notifications with the device token. All alternative mechanisms for background message delivery are unreliable, particularly on iOS platform.
@@ -1422,6 +1429,120 @@ When the command is successfully executed by the router, it should respond with
 ok = %s"OK"
 ```

+### Resolver commands
+
+Resolver commands implement public-namespace name resolution on the names-role
+router. A names router translates an opaque lookup key (such as `alice` or
+`alice.simplex.eth`) into a `NameRecord` carrying the channel and contact links
+the named party publishes.
+
+**Direct or forwarded.** RSLV is an unauthenticated command accepted both
+directly from a transport client and inside a `PFWD` block via the SMP proxy;
+the client chooses. Forwarded delivery preserves the two-server privacy property
+of the resolver design: the names router sees the lookup key but never the
+client IP, session, or identity, while the proxy router sees the client
+connection but cannot read the encrypted lookup key inside the forwarded
+transmission. Direct delivery is simpler but exposes the client's connection to
+the names router, so clients SHOULD prefer the forwarded path when proxying is
+available.
+
+**Backing store.** This protocol does not prescribe where the names router
+reads `NameRecord` from. The reference implementation forwards each RSLV to a
+companion REST resolver process (`scripts/resolver/snrc-resolve.py`) that
+queries the SNRC contract on Ethereum; alternative backings (different chains,
+DHT, etc.) are valid as long as they expose the documented HTTP shape (`GET
+/resolve/<name>` returning a `NameRecord` on 200, 404 / 400 for unknown names
+or TLDs, 502 for upstream RPC failures) or substitute a different transport
+while still returning a `NameRecord` matching the encoding below.
+
+#### Resolve name command
+
+The `RSLV` command carries the canonical fully-qualified name directly as the
+payload (not JSON):
+
+```abnf
+rslv = %s"RSLV" SP domain   ; domain = canonical name as non-space bytes, consuming the remainder of the transmission
+```
+
+`domain` is the UTF-8 canonical fully-qualified name with the TLD always
+explicit (e.g. `privacy.simplex`, `test.testing`, `example.com`), bounded to
+253 bytes.
+
+**Server-side validation.** The names router parses `domain` as a
+fully-qualified name (TLD required — bare labels are rejected) and forwards it
+to the configured backing resolver, which is the source of truth for which
+on-chain registry maps to each TLD.
+
+The names router responds with either an `RNAME` response carrying the resolved
+record, or an `ERR NAME` error whose subcode a client iterating across several
+configured servers can act on distinctly:
+
+| Response | Condition | Client action |
+|---|---|---|
+| `RNAME` | record resolved | use it |
+| `ERR NAME NOT_FOUND` | name not registered, unknown TLD, or malformed name | authoritative "no such name" — stop |
+| `ERR NAME NO_RESOLVER` | this router has no resolver (names role not enabled) | skip this server, try the next |
+| `ERR NAME RESOLVER <detail>` | transient failure: backing resolver error (upstream 5xx, transport, timeout, decode) | transient — retry or surface, do not treat as "not found" |
+
+A client SHOULD NOT broadcast a `name` to further servers after a name-capable
+router has answered (`NOT_FOUND` or `RESOLVER`), since that router has already
+seen the lookup key; `NO_RESOLVER` discloses nothing about the name beyond the
+fact that this router cannot resolve, so iterating past it is safe.
+
+#### Name record response
+
+The `RNAME` response carries a JSON-encoded record as the payload:
+
+```abnf
+rname = %s"RNAME" SP json-bytes   ; json-bytes consumes the remainder of the transmission
+```
+
+`json-bytes` MUST be a UTF-8 JSON object with the following schema:
+
+| Field | JSON type | Constraints |
+|---|---|---|
+| `name` | string | ≤ 255 bytes UTF-8 |
+| `nickname` | string | ≤ 255 bytes UTF-8; senders MUST emit the empty string `""` when unset |
+| `website` | string | ≤ 255 bytes UTF-8; same empty-string-when-unset rule |
+| `location` | string | ≤ 255 bytes UTF-8; same empty-string-when-unset rule |
+| `simplexContact` | array of strings | each a SimpleX contact link (primary first); empty array `[]` when unset |
+| `simplexChannel` | array of strings | each a SimpleX channel link (primary first); empty array `[]` when unset |
+| `eth` | string or null | ≤ 255 bytes UTF-8; senders MUST emit `null` when unset; receivers MUST also accept absent keys as unset |
+| `btc` | string or null | ≤ 255 bytes UTF-8; same null / absent rules |
+| `xmr` | string or null | ≤ 255 bytes UTF-8; same null / absent rules |
+| `dot` | string or null | ≤ 255 bytes UTF-8; same null / absent rules |
+| `owner` | string | `"0x"` followed by 40 lowercase hex characters (20 raw bytes) |
+| `resolver` | string | `"0x"` followed by 40 lowercase hex characters; the resolver contract address that produced the record |
+
+Text fields (`nickname`, `website`, `location`) use the empty string `""` as
+the "unset" sentinel: a backing resolver with no value for the field MUST emit
+an empty string, not JSON `null` and not an absent key. Link fields
+(`simplexContact`, `simplexChannel`) are arrays, primary link first, and use the
+empty array `[]` when unset. Coin fields (`eth`, `btc`, `xmr`, `dot`) use JSON
+`null` as the "unset" sentinel and MAY also be absent from the object entirely.
+
+The backing resolver filters records that are expired or otherwise unavailable
+(the names router then returns `ERR NAME NOT_FOUND` to the client), so the wire
+format carries no expiry field. Testnet-vs-mainnet status is derived from the
+queried TLD rather than an in-record flag.
+
+Receivers MUST tolerate extra unknown fields (forward-compatibility for future
+field additions). Adding a required field is a breaking change requiring an
+SMP version bump.
+
+**Field order is not significant.** Receivers parse JSON by key name, so object
+key order, insignificant whitespace, and number formatting carry no meaning;
+records are interpreted by decoded value, never compared byte-for-byte. Peers
+MUST NOT rely on a byte-canonical form — a different resolver or server may emit
+the same record with different key order or spacing. This order-independence is
+what makes the format forward-compatible (see the unknown-field rule above).
+
+**Wire-size budget.** The names router caps the resolver response it will
+accept (`resolver_max_response_bytes`, ≤ 16000 bytes, the default) so the
+re-encoded `RNAME` stays within the SMP proxied transmission budget of 16224
+bytes; a response over the cap is rejected as `ERR NAME RESOLVER`. The link
+arrays are bounded by this overall budget rather than a fixed per-field count.
+
 ## Transport connection with the SMP router

 ### General transport protocol considerations
@@ -0,0 +1,90 @@
+# Subscription performance
+
+No protocol changes. This is an implementation RFC addressing subscription performance bottlenecks in both the SMP router and the agent.
+
+## Problem
+
+Subscribing large numbers of queues is slow. A messaging client with ~300K queues per router across 3 routers takes over 1 hour to subscribe. For comparison, the NTF server with ~1M queues per router across 12 routers took 20-30 minutes (prior to NTF client services, now in master).
+
+Even on fast networks (cloud VMs), a client with 1.1M active subscriptions needed ~1.5M attempts (commands sent) to fully subscribe - ~36% retry rate caused by the timeout cascade described below.
+
+### Root causes
+
+#### 1. Router: per-command processing in batches
+
+Batch verification and queue lookups are already done efficiently for the whole batch in `Server.hs`. But `processCommand` is called per-command in a loop - each SUB does its own individual DB query for message peek/delivery. With ~135 SUBs per batch (current SMP version), that's 135 individual DB queries per batch instead of 1 batched query.
+
+For 300K queues, that's ~2200 batches x 135 queries = ~300K individual DB queries on the router, which is the dominant bottleneck when using PostgreSQL storage.
+
+NSUB is cheaper because it just registers for notifications without message delivery - no per-queue DB query.
+
+#### 2. Agent: all queues read and sent at once
+
+`getUserServerRcvQueueSubs` reads all queues for a `(userId, server)` pair in one query with no LIMIT. For 300K queues, the entire result set is loaded into memory, then all ~2200 batches are queued to send without waiting for responses.
+
+The NTF server agent uses cursor-style reading with configurable batch sizes (900 subs per chunk, 90K per DB fetch) and waits for each chunk to be processed before fetching the next.
+
+#### 3. No backpressure on sends
+
+`nonBlockingWriteTBQueue` bypasses the `sndQ` bound by forking a thread when the queue is full. All batches are queued immediately, and all their response timers start simultaneously. A 30-second per-response timeout means later batches time out not because the router is slow to respond to them specifically, but because they're waiting in the router's receive queue behind thousands of earlier commands.
+
+This causes cascading timeouts: timed-out responses trigger `resubscribeSMPSession`, which retries all pending subs. Three consecutive timeouts can trigger connection drop via the monitor thread, causing a full reconnection and retry of everything.
+
+## Solution
+
+### Part 1: Router - batched command processing
+
+Move the per-command processing loop inside command handlers so that commands of the same type within a batch can be processed together.
+
+Current flow:
+```
+receive batch -> verify all -> lookup queues all -> for each command: processCommand (individual DB query)
+```
+
+Proposed flow:
+```
+receive batch -> verify all -> lookup queues all -> group by command type -> process group:
+  SUB group: one batched message peek query for all queues
+  NSUB group: batch registration (already cheap, but can batch DB writes)
+  other commands: process individually as before
+```
+
+For SUB, the batched processing would:
+1. Collect all queue IDs from the SUB group
+2. Perform a single DB query to peek messages for all queues
+3. Distribute results back to individual responses
+
+This reduces ~135 DB queries per batch to 1, cutting router-side DB load by ~100x for subscriptions.
+
+Commands where batching doesn't matter (SEND, ACK, KEY, etc.) continue to be processed individually.
+
+### Part 2: Agent - cursor-based subscription with backpressure
+
+Replace the all-at-once fetch-and-send pattern with cursor-style batching, similar to what the NTF server agent does.
+
+Changes to `subscribeUserServer`:
+1. Fetch queues in fixed-size batches (e.g., configurable, default ~1000) using LIMIT/OFFSET or cursor-based pagination.
+2. Send each batch and wait for responses before sending the next.
+3. Remove the use of `nonBlockingWriteTBQueue` for subscription batches - use blocking writes or structured backpressure so response timers don't start until the batch is actually sent.
+
+This ensures:
+- Memory usage is bounded (not 300K queue records in memory at once)
+- Response timeouts are meaningful (timer starts when the router receives the batch, not when it's queued locally)
+- Retries are scoped to the failed batch, not all pending subs
+- Works on slow/lossy networks by naturally pacing sends
+
+### Part 3: Response timeout for batches
+
+The current per-response 30-second timeout doesn't account for batch processing time. Options:
+
+1. **Stagger deadlines**: later responses in a batch get proportionally more time. The `rcvConcurrency` field was designed for this but is never used.
+2. **Per-batch timeout**: instead of timing individual responses, timeout the entire batch with a budget proportional to batch size.
+3. **No timeout for subscription responses**: since subscriptions are sent as batches with backpressure (Part 2), and the connection is monitored by pings, individual response timeouts may not be needed. A subscription that doesn't get a response will be retried on reconnect.
+
+## Priority and ordering
+
+Part 1 (router batching) gives the biggest improvement and is independent of Parts 2/3.
+
+Part 2 (agent cursor + backpressure) eliminates the retry cascade and is critical for slow networks.
+
+Part 3 (timeout handling) is a refinement that can be addressed after Parts 1 and 2.
@@ -0,0 +1,114 @@
+---
+Proposed: 2026-07-11
+Protocol: agent-protocol (new version)
+Depends on: 2026-07-12-address-pqdr-keys
+---
+
+# One-off requests to service addresses
+
+Implementation plan: to follow, after this and the address-DR RFC are reviewed.
+
+## Problem
+
+Client applications need to interact with services, for example: badge issuance, directory requests, telemetry submissions, blockchain reads and writes, LLM calls. The only communication primitive available today is a duplex connection, so each of these interactions requires the full connection procedure - creating queues, key agreement, double ratchet initialization - and leaves persistent state on both sides: queues, ratchet state, connection records, message history.
+
+This is the wrong primitive for most service interactions:
+
+1. Cost. To send the first request to a not yet connected service, the client and the service exchange multiple commands across two servers. For "search the directory" all of it is overhead. The setup cost also creates an incentive to keep connections open, and a service with N users who used it once permanently holds N sets of queues and ratchet states.
+
+2. Privacy. A connection is a stable pairwise pseudonym. If a service were to use a duplex connection, it could link all requests made over it into a profile: search history in the directory, blockchain operations linked even when different on-chain keys are used, telemetry that becomes longitudinal tracking. The client also accumulates history that can be recovered from the device. Where continuity is needed, it can be provided in the application protocol (e.g., a token included in requests), without a transport-level identity.
+
+3. Encryption. Messages sent to contact addresses outside an established connection have a single layer of X25519 encryption, with no post-quantum protection and no forward secrecy. This is not acceptable for service requests.
+
+In-app service addresses should be stored as names resolving to links via the existing addressing layer (server host in the link authority, current link data retrieved with `LGET`), so that service links can be changed without redeploying the apps. Name resolution is already supported, and out of scope.
+
+## Security objectives
+
+1. Requests from the same client must not be linkable to each other by the service or by servers, and no long term state is created on either side in the transport layer.
+2. Post-quantum resistant end-to-end encryption of requests and replies.
+3. Reply authenticity must be verifiable against the link; substitution, replay, dropping or reordering of replies by servers must be detectable.
+4. A repeated request for the same operation must not be executed twice.
+
+## Solution
+
+A service address is an ordinary short-link contact address. The client sends one request to the address queue and receives replies in a reply queue it creates for the request. The double ratchet is established from the address's published keys (see the address-DR RFC): the request is the first ratchet message, and replies are subsequent ratchet messages. So a request-response exchange is a short-lived one-directional double ratchet connection, established from the first message and removed after the last.
+
+The exchange:
+
+1. Retrieve the address link data (`LGET`, via proxy when IP protection is needed): the root key, the identity key, the prekey with its id, and the KEM key.
+2. Create a reply queue (`NEW`, subscribed).
+3. Establish the sending ratchet from the published keys (`pqX3dhSnd`, `initSndRatchet`). Build the request: the reply queue, the requester's X3DH parameters, and the payload encrypted under the ratchet. Encrypt the whole request to the address queue and send it once (unauthenticated `SEND`, via proxy when IP protection is needed). There is no transport retry; a reply is the success signal, and a hard error fails the request.
+4. The service establishes the receiving ratchet from its private keys and the request's X3DH parameters (`pqX3dhRcv`, `initRcvRatchet`), decrypts the payload, and delivers it to the service application. To reply it creates a send connection with the ratchet and sends reply messages to the reply queue, each encrypted under the ratchet.
+5. The client decrypts and delivers each reply message to the application. The first reply message returns from the request; later reply messages are delivered through a callback the application registered. The exchange ends on a reply marked final. The client deletes the reply queue and the ratchet on the final message, the deadline, or when the application cancels.
+
+How this meets the objectives:
+
+1. Unlinkability: fresh X3DH keys and a fresh reply queue per request; the sender's IP address and session are protected by existing private routing; the reply queue and both ratchets are removed after the exchange; nothing is shared between two requests.
+2. Encryption: the double ratchet with its sntrup761 KEM, from the first message.
+3. Authenticity: the ratchet is established against the identity key committed by the link hash, so a decryptable reply proves it came from the address owner; the ratchet message numbering detects dropped and reordered replies. No separate signature is needed.
+4. Single execution: the service identifies a request by the hash of its decrypted payload and, within a fixed retention period, re-sends the stored replies for a repeated request without running the operation again.
+
+## Design
+
+Syntax uses [ABNF][1] with [case-sensitive strings extension][2]. `SMPQueueInfo`, `agentVersion`, and the X3DH and ratchet types are as in the [agent protocol](../protocol/agent-protocol.md) and `Crypto.Ratchet`.
+
+### Correlation and chat
+
+A reply is connected to its request by the reply queue: each request has its own reply queue, and every message in that queue is a reply to that request. The request hash (of the decrypted payload) is used only for idempotency. The application sets an id inside the payload to make two requests the same operation or different ones; the agent does not read it.
+
+Both ends are chat bots on the chat library over the agent. The chat library serializes a service command into the request payload and deserializes the responses; the agent transports them, establishes and removes the ratchet, and correlates by reply queue.
+
+### Request
+
+A new agent envelope, shaped like `AgentConfirmation` (X3DH parameters to establish the ratchet, plus a body encrypted under it):
+
+```abnf
+agentRequest = agentVersion %s"Q" replyQueues prekeyId sndE2EParams encRequest
+replyQueues = length 1*SMPQueueInfo ; the first is used; more are for redundancy
+prekeyId = shortString ; the published prekey used, from link data
+sndE2EParams = <requester Snd X3DH parameters, see address-DR RFC>
+encRequest = <ratchet-encrypted request payload>
+```
+
+The whole `agentRequest` is encrypted to the address queue with the per-queue layer and sent with `SEND`, as an invitation is today. The reply queue keys and the X3DH parameters are not visible to servers. A request must fit one message; a larger payload is an XFTP file description in the payload.
+
+The request hash is the SHA3-256 of the decrypted payload - the same bytes on both sides. There is no transport retry; a hard error (`AUTH`, `QUOTA`) fails the request, and the application decides whether to send a new one.
+
+### Replies
+
+The service creates a send connection with the ratchet and sends reply messages to the reply queue, each encrypted under the ratchet. A reply message uses a new agent envelope:
+
+```abnf
+agentResponse = agentVersion %s"P" final responses
+final = %s"T" / %s"F" ; T - no more reply messages follow
+responses = length 1*responseItem ; non-empty list of application responses
+responseItem = largeString ; opaque application response
+```
+
+Each message includes a list of responses, so responses known together are sent in one message and responses that become known over time are sent in separate messages. The message is encrypted and numbered by the ratchet, which authenticates it against the committed identity key and detects dropped or reordered messages; no separate signature is used.
+
+The first reply message returns from the request. Later reply messages are delivered through the callback the application registered with the request, while the process runs. The exchange ends on a message with `final = T`. The client deletes the reply queue and the ratchet on that message, on the deadline, or when the application cancels. Deleting the reply queue stops further replies. The transport keeps no exchange across a client restart; the application keeps its own state and sends a new request when it needs to.
+
+### Rejection
+
+The service refuses a request with the `AgentRejection` envelope from the [communicating rejection RFC](../../simplex-chat/docs/rfcs/2024-03-22-communicating-reject.md), sent to the reply queue under the ratchet, with an opaque application reason. The same envelope communicates refusal of a connection request, where today it is dropped silently. A rejection ends the exchange like a final reply.
+
+### Idempotency
+
+The service keeps, for a fixed retention period it chooses (1 to 24 hours, in service configuration, not in link data), the request hash, the ordered response messages it produced, and the reply queues and ratchets subscribed under that hash. A repeat request with the same hash does not reach the service application:
+
+- while the first request is being answered, the repeat establishes its own ratchet and reply queue, is added to the record, receives the responses already produced, and receives each later response too.
+- after the operation completed, the repeat receives the whole stored sequence of responses, re-encrypted under its own ratchet.
+
+The stored responses are the application response bytes, not the ratchet ciphertext, because a repeat establishes a new ratchet and the responses are re-encrypted for it. This gives single execution over at-least-once delivery. After the retention period a request with the same hash is a new operation and runs again.
+
+### Out of scope
+
+- Recovery across restart: the transport keeps no exchange across a client restart; the application persists its own state and sends a new request when it needs to.
+- Service-initiated messages: there is no standing channel; use a connection where the service must reach the client without a request.
+- Abuse protection beyond existing queue quotas: services can require application-level credentials (e.g., a badge) in the request payload; rate limiting is a separate discussion.
+- Scaling request reception: a single address queue bounds service throughput; distributing reception across multiple queues or relays (the existing `relays` field in contact link data) is a separate question, but it would fit well with name resolving to multiple addresses, both for redundancy, reliability and higher throughput.
+- Name resolution: existing addressing layer.
+
+[1]: https://tools.ietf.org/html/rfc5234
+[2]: https://tools.ietf.org/html/rfc7405
@@ -0,0 +1,83 @@
+---
+Proposed: 2026-07-12
+Protocol: agent-protocol (new version)
+---
+
+# Establishing the double ratchet from address data
+
+## Problem
+
+A contact address receives a connection request as an `AgentInvitation` message, encrypted only with the per-queue X25519 layer. The double ratchet is established later: the address owner joins the requester's connection request, generates its X3DH keys, and sends them in the confirmation. So the first message to an address - the invitation and the profile in it - is not under the double ratchet, and has no post-quantum protection.
+
+The cause is that the address owner's X3DH contribution is generated per request and sent in the confirmation, so it cannot exist before the requester's first message.
+
+## Solution
+
+Publish the address owner's X3DH contribution in the address link data, so a requester can establish the double ratchet in its first message. The requester runs the existing `pqX3dhSnd` against the published keys, initializes a sending ratchet, and encrypts its first message under it. The owner runs the existing `pqX3dhRcv` against its stored private keys and the requester's X3DH keys from the message, initializes a receiving ratchet, and decrypts it.
+
+Publish the owner's X3DH contribution - two X448 keys and an optional sntrup761 KEM key, with the e2e version range - as one bundle in the mutable contact user data, signed by the root key. The bundle is the existing `RcvE2ERatchetParamsUri` type that a one-time invitation already advertises, with an id for rotation.
+
+This is backward compatible. A requester that does not use the published bundle sends a current `AgentInvitation` with its own X3DH keys, and the owner does what it does today: generates fresh X3DH keys and sends them in the confirmation. The owner branches on whether the incoming message uses the published bundle.
+
+Three properties follow. The first message, including the profile, is under the double ratchet, which closes the profile gap and gives it post-quantum protection through the ratchet's sntrup761 KEM. A decryptable message proves the sender established X3DH against the root-signed keys, so it authenticates the address owner without a separate signature. And because the bundle is in mutable data, an existing address can advertise the double ratchet by updating its mutable data - no new link.
+
+## Design
+
+Syntax uses [ABNF][1] with [case-sensitive strings extension][2]. Key and ratchet types are as in `Crypto.Ratchet` and the [agent protocol](../protocol/agent-protocol.md); all DH keys are X448, the KEM is sntrup761.
+
+### Published keys in link data
+
+The owner's X3DH contribution is a ratchet-keys bundle appended to the mutable contact user data, signed by the root key. Nothing is added to the immutable fixed link data:
+
+```abnf
+userContactData =/ ratchetKeys ; appended, ignored by earlier versions
+ratchetKeys = %s"0" / (%s"1" ratchetKeyId e2eParams)
+ratchetKeyId = shortString ; identifies this bundle, changes on rotation, echoed in the request
+e2eParams = <RcvE2ERatchetParamsUri: e2e version range, two X448 keys, optional sntrup761 key>
+```
+
+`e2eParams` is the existing `RcvE2ERatchetParamsUri` - the same type a one-time invitation advertises - so a requester reads it, negotiates the concrete e2e version against its own range, and runs `pqX3dhSnd` against it, exactly as it does for an invitation. The KEM key is optional (the params' KEM field is a `Maybe`), controlled by the address's initial-keys mode, the same 3-way choice as invitations: advertise the KEM (post-quantum from the first message), advertise X448-only but still support post-quantum if the requester proposes its own KEM (one message later, avoiding the ~1158-byte key in link data), or no post-quantum.
+
+The owner keeps the private side of each bundle - the two X448 private keys and, when PQ is on, the KEM keypair - indexed by `ratchetKeyId`. On rotation with `LSET` it publishes a new bundle with a new `ratchetKeyId` and keeps the previous private keys for a window covering queue message retention, so a request that used a just-rotated bundle still decrypts. Because the bundle is in mutable data, an existing address advertises the double ratchet by updating its mutable data - no new link, no re-creation.
+
+### Request confirmation
+
+A requester that uses the published keys establishes the sending ratchet before its first message, so it sends that message as a confirmation, not an invitation - the same envelope a joining party sends in a connection. The confirmation gains an optional `ratchetKeyId` naming the bundle the requester used, so the owner selects the matching private keys:
+
+```abnf
+agentConfirmation =/ ratchetKeyId ; the bundle the requester used, echoed; absent on other confirmations
+```
+
+The confirmation holds the requester's Snd X3DH parameters (so the owner runs `pqX3dhRcv`) and, encrypted under the ratchet, the first message. A confirmation with `ratchetKeyId` on a contact address takes the published-key path; an `AgentInvitation`, as today, takes the current path where the owner generates fresh X3DH keys and returns them in its own confirmation. A connection-request URI is unchanged: it advertises the requester's Rcv parameters and must not include Snd parameters.
+
+### Establishing the ratchet
+
+Requester:
+
+1. Retrieve link data (`LGET`), read the bundle - its `ratchetKeyId` and `e2eParams` (`RcvE2ERatchetParamsUri`) - and negotiate the concrete e2e version against its own range.
+2. `generateSndE2EParams` for its own X3DH contribution - encapsulating to the bundle's KEM if it advertises one, or proposing its own KEM if the requester wants post-quantum and the bundle is X448-only.
+3. `pqX3dhSnd` against the bundle's parameters, then `initSndRatchet` - the sending ratchet.
+4. Encrypt the first message under the ratchet, and send a confirmation with its Snd parameters and `ratchetKeyId`.
+
+Owner:
+
+1. On a confirmation with `ratchetKeyId` on a contact address, select the private X3DH keys and, if any, KEM keypair by `ratchetKeyId` (current or a retained previous generation).
+2. `pqX3dhRcv` against the requester's Snd parameters with those private keys, then `initRcvRatchet` - the receiving ratchet. Decrypting the first message advances the ratchet and gives it a send side, so the owner can reply.
+3. Decrypt, and reply under the ratchet.
+
+A request whose `ratchetKeyId` is no longer retained cannot be decrypted; the owner does not learn the requester or its reply address, and the requester's attempt fails at its own timeout.
+
+### Authentication
+
+The ratchet-keys bundle is in the mutable link data, signed by the root key. A decryptable message proves the sender established X3DH against those root-signed keys: an SMP server cannot substitute them without forging the root signature (`decryptLinkData` verifies it), which is the X3DH anti-substitution property. Where a message today relies on a separate signature over its content for authenticity, this establishment provides it, and the signature is not needed. The root Ed25519 key is the address's signing identity; the X3DH keys are separate DH keys (X448), and X3DH is over crypto_box, so deniability is preserved. A malicious server can still serve an older but validly-signed bundle (rollback to a retired generation); this is bounded by the retention window and by the ratchet advancing after the first message, and a per-key signature would not prevent it. Reusing a bundle across requesters is consistent with the address already being a shared identifier.
+
+## Uses
+
+- Invitations to an address, and the profile in them, are under the double ratchet from the first message.
+- An existing address gains the double ratchet when the app updates its mutable link data (`LSET`, with the user's confirmation and current profile, combined with the full→short address migration); no new link is issued.
+- The service RPC (see the RPC RFC) establishes the ratchet this way to send the request as the first ratchet message.
+
+This RFC depends on nothing else here. It replaces the need for the PQ-queue RFC in the address case, because the ratchet provides post-quantum protection for the first message; the PQ-queue RFC remains for first messages that do not establish a ratchet.
+
+[1]: https://tools.ietf.org/html/rfc5234
+[2]: https://tools.ietf.org/html/rfc7405
@@ -0,0 +1,42 @@
+---
+Proposed: 2026-07-12
+Protocol: smp-client (new version)
+---
+
+# Post-quantum encryption of the SMP queue layer
+
+## Problem
+
+A message sent to a queue outside an established double ratchet has one layer of end-to-end encryption: NaCl crypto_box over an X25519 DH secret. The sender generates an ephemeral X25519 key, computes the secret with the recipient's per-queue DH key, and puts its ephemeral key in the message public header (`agentCbEncryptOnce`). This layer protects invitations, confirmations, and the profile sent with them.
+
+It is not post-quantum. An adversary that records this traffic and later has a quantum computer can recover the X25519 secret and decrypt it. The double ratchet adds a post-quantum KEM once it is established, but the first message to a queue, before the ratchet, has only X25519.
+
+This RFC adds post-quantum protection to the single-shot queue encryption itself, for cases that do not establish a double ratchet from the first message. Where a double ratchet is established from the first message (see the address-DR RFC), the ratchet provides post-quantum protection and this layer is not needed.
+
+## Solution
+
+Extend the single-shot queue encryption to a hybrid X25519 + sntrup761 scheme, in a new SMP client version. The recipient publishes a KEM encapsulation key alongside its per-queue DH key. The sender encapsulates to it, combines the KEM shared secret with the X25519 DH secret, and encrypts the body with the combined secret. The KEM ciphertext travels in the message public header next to the ephemeral X25519 key.
+
+Recording the traffic and breaking X25519 later is not sufficient: without breaking sntrup761 as well, the combined secret is not recoverable.
+
+## Design
+
+The message public header (`PubHeader`) gains a hybrid variant, selected by a version and a tag, so older senders and the empty-header case are unchanged:
+
+```abnf
+smpPubHeaderHybrid = smpClientVersion %s"2" senderPublicDhKey kemCiphertext
+senderPublicDhKey = length x509encoded ; sender ephemeral X25519 key
+kemCiphertext = largeString ; sntrup761 ciphertext, 1039 bytes
+```
+
+The secret combines both shared secrets, and the body is encrypted with NaCl secret_box (the DH-only path uses crypto_box today; the combined secret is no longer a plain DH result, so it is used as a secret_box key), padded to the same lengths:
+
+```
+secret = HKDF(dh(recipient key, sender ephemeral key) || KEM shared secret)
+```
+
+The recipient's KEM encapsulation key is distributed the same way its per-queue DH key is today - in the queue address for a connection request, and in link data for a short link. The KEM ciphertext is stored the same way the ephemeral DH key is: in the public header, readable by the destination server (and not by the proxy with proxied sending), which cannot derive the secret without the recipient's KEM private key.
+
+The recipient stores the computed secret the way the per-queue DH secret is stored on receiving the first message (`setRcvQueueConfirmedE2E`), and reuses it for later messages on the queue.
+
+Sizes: the KEM ciphertext is 1039 bytes and the encapsulation key 1158 bytes. Link data user data is padded to 13784 bytes, so the key fits with application data. This RFC is independent of the RPC, SSND, and address-DR RFCs.
@@ -0,0 +1,55 @@
+---
+Proposed: 2026-07-12
+Protocol: smp (new version)
+---
+
+# SSND: combined secure-and-send command
+
+## Problem
+
+Two SMP flows secure a messaging queue and then immediately send the first message to it, as two commands and two round trips:
+
+- The fast connection handshake: the joining party secures the queue with `SKEY`, then sends the confirmation with `SEND`.
+- Any first send to a sender-securable queue where the sender both secures it and delivers the first message.
+
+The two commands express one intent - "this is my key, and here is my first message" - so they can be one command and one round trip. The combination must be idempotent, because the first send is retried on network failure and a queue is often secured before the response is known. `SKEY` is already idempotent (a repeat with the same key succeeds). `SEND` is not, so a naive combination would deliver a duplicate message on retry.
+
+## Solution
+
+A new command `SSND` combines `SKEY` and `SEND` in one transmission, idempotent in both parts:
+
+- Key part: as `SKEY` - a repeat with the same key succeeds, a different key fails with `AUTH`.
+- Send part: the server keeps the hash of the message until it is acknowledged, and reports a repeat of the same message as delivered without delivering it again.
+
+The server-side hash covers the common case, when the retry arrives before the message is acknowledged. A retry that arrives after the acknowledgement is delivered as a duplicate and discarded by the receiving agent by message hash, as duplicate messages are discarded today.
+
+## Design
+
+Syntax uses [ABNF][1] with [case-sensitive strings extension][2]. `senderAuthPublicKey`, `msgFlags` and `smpEncMessage` are as in the [SMP protocol](../protocol/simplex-messaging.md).
+
+```abnf
+secureSend = %s"SSND " senderAuthPublicKey SP msgFlags SP smpEncMessage
+senderAuthPublicKey = length x509encoded
+```
+
+`SSND` is a sender command, authorized with the key it sets, and accepted only on messaging-mode queues (`QMMessaging`), where the sender can secure the queue. The server responds `OK` or `ERR`.
+
+Server processing:
+
+1. Secure the queue with the key, as `SKEY`. A repeat with the same key succeeds; a different key returns `AUTH`.
+2. If the queue holds an unacknowledged message whose stored hash equals the hash of this message, respond `OK` without storing it again.
+3. Otherwise store the message, keep its hash with the queue until the message is acknowledged, and deliver it.
+
+The stored hash is one value per not-yet-acknowledged queue message. It is removed when the message is acknowledged. All queue store backends (in-memory, journal, PostgreSQL) keep it.
+
+`SSND` composes with the proxy protocol without change: `proxySMPCommand` forwards any sender command through `PFWD`/`RFWD`, so `SSND` is proxied as `SEND` and `SKEY` are today.
+
+## Uses
+
+- The fast connection handshake replaces `SKEY` then the `SEND` confirmation with one `SSND`.
+- The service RPC response (see the RPC RFC) secures the reply queue and sends the first reply with one `SSND`.
+
+This RFC is independent of the RPC, PQ-queue, and address-DR RFCs and can be implemented on its own.
+
+[1]: https://tools.ietf.org/html/rfc5234
+[2]: https://tools.ietf.org/html/rfc7405
@@ -0,0 +1,97 @@
+---
+Proposed: 2026-08-09
+Protocol: agent-protocol v8
+Diagram: ../protocol/diagrams/duplex-messaging/queue-rotation-fast.svg
+---
+
+# Fast queue rotation
+
+## Problem
+
+In the current rotation the peer returns `QKEY` to the initiator over the initiator's current
+receiving queue. When that queue's server is unavailable the rotation cannot complete, so a client
+cannot move away from a failed server.
+
+## Solution
+
+Both the current rotation and v8 add a queue, deliver to both queues while the rotation is in
+progress, and remove the old queue; the recipient drops duplicates in both. The main difference is where
+the new queue's secret is established. In the current rotation it is established over the current
+queue, by `QKEY`, so it cannot complete when the current server is down. In v8 the peer establishes the
+new queue's secret over the new queue itself — a confirmation it sends on R' — so establishing the
+secret no longer depends on the current queue, and the rotation completes even when the current server
+is down.
+
+v8 also starts writing to both queues earlier: from the moment the queue is added, including the
+current queue's not-yet-delivered backlog. So the initiator adds the new queue with `QADD`; from that
+point the peer writes every message to both the current queue and R'. Once R' is secured the peer
+writes new messages to it alone, while the current queue delivers whatever was already scheduled on it
+and a final `QEND`, and is then removed. Because the recipient drops duplicates, neither the order of
+arrival nor which queue carries a message matters, provided each message arrives on at least one queue
+— with one exception, the confirmation, which is always the first message on R'. A dead new queue does
+not stop delivery either, because the current queue keeps delivering until R' is secured.
+
+Roles: A initiates (its receiving queue rotates; A receives on the new queue R'). B is the peer (B
+holds the sending queue to A, secures R', and delivers to both).
+
+Sequence:
+
+    A -> R'       : create new queue (messaging mode, SKEY allowed)
+    A -> S -> B   : QADD(R')          (over A's sending queue; A's current server untouched)
+    B             : from QADD, schedule every message and the current backlog on both queues
+    B -> current  : deliver the scheduled messages (R' holds its copies while securing)
+    B -> R'       : SKEY              (authorize B as sender)
+    B -> R'       : confirmation      (empty; establishes R' secret; first message on R')
+    B -> R'       : deliver R''s held copies (A dedups), then new messages to R' only
+    B -> current  : deliver the remaining tail, then QEND(current)
+    B -> R'       : QEND(current)
+    A             : on QEND, delete the current queue; keep receiving on R'
+
+## Confirmation
+
+The confirmation is the only message a recipient can read on a queue that is not yet secured, and it
+establishes the queue's shared secret without depending on the current queue. Because a data message
+that reached R' before the confirmation could not be read, the confirmation is the first message the
+peer sends on R', and the peer does not start ordinary delivery on R' until the confirmation has been
+sent.
+
+The confirmation body is empty: both parties already know each other, so no profile or reply queue is
+sent. It is sealed by the queue's box (keyed by the shared secret being established) and is not
+additionally encrypted with the double ratchet, so rotation does not advance the message ratchet.
+
+## Termination
+
+`QEND` names a queue to remove and is delivered on both queues. On receipt the recipient deletes the
+named queue; on send the peer removes its sending queue of that address. `QEND` is a general
+queue-removal message — the peer can remove either queue with it — so on the wire a rotation is the
+addition of a queue (`QADD`) and the later removal of the replaced one (`QEND`), each an ordinary
+operation on the queue set rather than a `QTEST`-style completion. Delivering `QEND` on the removed
+queue is best effort; the copy on the surviving queue removes it and reaches the recipient even when
+the removed server is dead.
+
+## Per-queue secret
+
+R' secret is a fresh Diffie-Hellman between the peer's queue key, sent in the confirmation header, and
+the initiator's R' key. It does not depend on any current queue, so redundancy of current queues is
+unaffected.
+
+## Compatibility
+
+Fast rotation runs only when the connection's agreed agent protocol version is 8 or higher; the peer
+chooses it. Otherwise the `QKEY`/`QUSE` exchange is used. `QEND` is defined at version 8 and is only
+sent during fast rotation, so peers below version 8 never receive it.
+
+    new A / new B  : fast (QADD, confirmation on R', QEND)
+    new A / old B  : slow (old B returns QKEY; new A keeps the QKEY/QUSE handling)
+    old A / new B  : slow (agreed version below 8; new B returns QKEY)
+    old A / old B  : slow
+
+The recipient does not choose by version; it reacts to whichever message arrives — `QKEY`, or a
+confirmation on R' followed later by `QEND`.
+
+## Dead current server
+
+The initiator keeps reading messages on the new queue and removes the current queue when `QEND`
+arrives there, without waiting for the current server. Nothing is lost, because every message is
+scheduled on the new queue; the only cleanup that a dead current server delays is the deletion
+of its queue, which is retried a bounded number of times and then abandoned.
@@ -67,14 +67,14 @@ if [ ! -f "${confd}/smp-server.ini" ]; then

  # Fix path to certificates
  if [ -n "${WEB_MANUAL}" ]; then
-    sed -i -e 's|^[^#]*https: |#&|' \
-           -e 's|^[^#]*cert: |#&|' \
-           -e 's|^[^#]*key: |#&|' \
-           -e 's|^port:.*|port: 5223|' \
+    sed -i -e 's|^[^#]*https = |#&|' \
+           -e 's|^[^#]*cert = |#&|' \
+           -e 's|^[^#]*key = |#&|' \
+           -e 's|^port = .*|port = 5223|' \
           "${confd}/smp-server.ini"
  else
-    sed -i -e "s|cert: /etc/opt/simplex/web.crt|cert: $cert_path/$ADDR.crt|" \
-           -e "s|key: /etc/opt/simplex/web.key|key: $cert_path/$ADDR.key|" \
+    sed -i -e "s|cert = /etc/opt/simplex/web.crt|cert = $cert_path/$ADDR.crt|" \
+           -e "s|key = /etc/opt/simplex/web.key|key = $cert_path/$ADDR.key|" \
           "${confd}/smp-server.ini"
  fi
 fi
@@ -76,7 +76,7 @@ if [ ! -f "${confd}/file-server.ini" ]; then

  # Optionally, set password
  if [ -n "${PASS}" ]; then
-    sed -i -e "/^# create_password:/a create_password: $PASS" \
+    sed -i -e "/^# create_password =/a create_password = $PASS" \
           "${confd}/file-server.ini"
  fi
 fi
@@ -237,11 +237,11 @@ checks() {
    exit 1
  fi

+  mkdir -p "$path_conf_info" "$path_tmp_bin"
+
  check_versions
  check_distro

-  mkdir -p $path_conf_info $path_tmp_bin
-
  return 0
 }

@@ -0,0 +1,22 @@
+# ============================================================================
+# Required settings — the stack will not start without these.
+# ============================================================================
+
+# Ethereum network: mainnet (the SNRC `.testing` contracts live on mainnet)
+# or holesky (test). Mainnet full sync needs ~1 day and ~1.2 TB NVMe.
+NETWORK=mainnet
+
+# Beacon checkpoint-sync URL — used ONCE on first sync. Must expose the heavy
+# /eth/v2/debug/beacon/states/finalized endpoint (generic beacon APIs do not;
+# use a dedicated checkpoint provider). List: https://eth-clients.github.io/checkpoint-sync-endpoints/
+#   mainnet: https://mainnet-checkpoint-sync.attestant.io  (also beaconstate.info, sync-mainnet.beaconcha.in)
+#   holesky: https://checkpoint-sync.holesky.ethpandaops.io
+TRUSTED_NODE_URL=https://mainnet-checkpoint-sync.attestant.io
+
+# ============================================================================
+# Optional overrides — sensible defaults are baked into docker-compose.yml,
+# so leave these commented unless you need to change them.
+# ============================================================================
+
+# Nimbus NAT (default: any). For a stable public node set an explicit IP:
+#   NAT=extip:1.2.3.4        # your public IPv4: curl -s ifconfig.me
@@ -0,0 +1,146 @@
+# Self-hosted SNRC stack
+
+One `docker compose up` runs the self-hosted SimpleX Namespace (SNRC) backend
+against **Ethereum mainnet** (where the `.testing` contracts live):
+
+| # | Component | What it does |
+|---|---|---|
+| 1 | **reth + nimbus** | self-hosted Ethereum node (`--minimal` — enough for the resolver's `eth_call` at chain head) |
+| 2 | **resolver** | the REST resolver the smp-server's `[NAMES]` role queries (`snrc-resolve.py`) |
+
+## Requirements
+
+- **Docker** + Compose v2.
+- **≥ 300 GB NVMe SSD** for `reth --minimal` (~260 GB on mainnet; TLC, not QLC
+  — QLC stalls during sync) + **32 GB RAM**, fast multi-core CPU.
+- **~1 day** for the initial reth sync. The resolver returns errors until reth
+  has caught up — that's expected.
+- Firewall: open p2p ports `30303` (tcp/udp) and `9000` (tcp/udp).
+
+## 1. Configure
+
+Edit `.env` — the defaults work as-is; override only if needed:
+
+```sh
+NETWORK=mainnet                                               # default
+TRUSTED_NODE_URL=https://mainnet-checkpoint-sync.attestant.io # default
+```
+
+Everything else (NAT) has a working default baked into `docker-compose.yml`;
+uncomment the hints in `.env` only to override.
+
+## 2. Run
+
+```sh
+cd scripts/resolver
+docker compose up -d
+docker compose logs -f reth resolver
+```
+
+`depends_on` handles ordering automatically (start node → start resolver).
+
+## 3. Wait for the node to sync
+
+```sh
+docker compose logs --tail=20 reth
+```
+
+This is the long pole (~1 day on mainnet). Until reth is synced the resolver
+returns `502`.
+
+## Verify
+
+Run these once the stack is up (the node-dependent ones pass after sync):
+
+**1. reth is reachable and reporting a block:**
+```sh
+curl -s -X POST http://127.0.0.1:8545 \
+  -H 'content-type: application/json' \
+  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' | jq
+```
+
+**2. resolver is healthy:**
+```sh
+curl -s http://127.0.0.1:8000/health | jq
+# → {"ok": true, "rpc": "http://reth:8545", "registries": {"testing": "0x…", "simplex": ""}}
+```
+
+**3. resolver resolves a live name** (`foobar.testing` is a populated test name):
+```sh
+curl -s http://127.0.0.1:8000/resolve/foobar.testing | jq
+# → {"name":"foobar.testing","nickname":"Foo","simplexContact":["https://smp16.simplex.im/a#…"], … }
+```
+
+**Wire your smp-server:** in its `[NAMES]` section set
+`resolver_endpoint: http://127.0.0.1:8000` (no auth needed for loopback).
+
+## Ports (all loopback unless noted)
+
+| Service | Host | Purpose |
+|---|---|---|
+| reth JSON-RPC | `127.0.0.1:8545` | smp-server RPC |
+| reth p2p | `:30303` tcp/udp | Ethereum sync (open on firewall) |
+| nimbus p2p | `:9000` tcp/udp | beacon sync (open on firewall) |
+| nimbus REST | `127.0.0.1:5052` | beacon API |
+| **resolver** | `127.0.0.1:8000` | SNRC REST (`/resolve`, `/health`) |
+
+## Caveats
+
+- **All images track `:latest`** (reth, nimbus) — you get upstream fixes on each
+  `docker compose pull`; re-run the verify checks after pulling.
+- All ports bind to loopback; expose only what you put behind a TLS reverse proxy.
+
+## Teardown
+
+```sh
+docker compose down       # stop, keep all state
+docker compose down -v    # also wipe volumes → full re-sync
+```
+
+`down -v` wipes the chain data (full re-sync on the next `up`).
+
+---
+
+## Resolver API reference
+
+The resolver (`snrc-resolve.py`, host `127.0.0.1:8000`) is also runnable
+standalone for local dev (no Docker), via [`uv`](https://docs.astral.sh/uv/):
+
+```sh
+uv run scripts/resolver/service/snrc-resolve.py  # defaults to local reth + mainnet .testing
+```
+
+### Response shape
+
+```jsonc
+{
+  "name": "foobar.testing",
+  "nickname": "Foo", "website": "https://foo.bar", "location": "",
+  "simplexContact": ["https://smp16.simplex.im/a#…", "https://smp11…"],  // primary first, fallbacks after
+  "simplexChannel": [],
+  "eth": null, "btc": "bc1q…", "xmr": "4ANz…", "dot": "139G…",
+  "owner": "0xd83b…", "resolver": "0x80fa…"
+}
+```
+
+`simplexContact`/`simplexChannel` are arrays (a name can advertise multiple SMP
+servers; clients try them in order). On-chain they're a single comma-separated
+text record; the resolver splits/trims/drops-empties. Address encodings are
+canonical per chain (EIP-55 / bech32 / SS58 / Monero-base58). Subnames work
+identically (`bar.foobar.testing`).
+
+### Status codes
+
+| Status | Meaning |
+|---|---|
+| 200 | resolved |
+| 400 | TLD not configured, or not a fully-qualified name |
+| 404 | name has no resolver set on the registry |
+| 502 | upstream RPC error / reth not synced |
+
+### Configuring registries
+
+Defaults to mainnet `.testing` (`0x03f438…`); `.simplex` is unset until
+deployed. Override per TLD via env on the `resolver` service in
+`docker-compose.yml` (`SNRC_REGISTRY_TESTING` / `SNRC_REGISTRY_SIMPLEX`), or as
+env vars for the standalone script.
@@ -0,0 +1,160 @@
+services:
+  # One-shot setup (runs as root): generates /jwt/jwt.hex and chowns the
+  # nimbus-data volume to UID 1000 (the user Nimbus runs as inside its image).
+  # Without this chown Nimbus gets "Permission denied" on its data dir
+  # because docker creates fresh named volumes owned by root.
+  init:
+    image: alpine:latest
+    volumes:
+      - jwt:/jwt
+      - nimbus-data:/nimbus-data
+    command: >
+      sh -c '
+        set -e;
+        if [ ! -f /jwt/jwt.hex ]; then
+          apk add --no-cache openssl >/dev/null;
+          openssl rand -hex 32 | tr -d "\n" > /jwt/jwt.hex;
+          chmod 644 /jwt/jwt.hex;
+          echo "Generated /jwt/jwt.hex";
+        else
+          echo "jwt.hex already exists";
+        fi;
+        chown 1000:1000 /nimbus-data;
+        echo "Chowned /nimbus-data to 1000:1000";
+      '
+    restart: "no"
+
+  # One-shot: fetches a recent finalised checkpoint into the Nimbus data dir
+  # using the trustedNodeSync subcommand. Skipped if the data dir is already
+  # initialised, so subsequent compose-ups are no-ops.
+  nimbus-checkpoint-sync:
+    image: statusim/nimbus-eth2:multiarch-latest
+    depends_on:
+      init:
+        condition: service_completed_successfully
+    volumes:
+      - nimbus-data:/home/user/nimbus-eth2/build/data
+    entrypoint:
+      - sh
+      - -c
+      - |
+        if [ -d /home/user/nimbus-eth2/build/data/${NETWORK}/db ]; then
+          echo "Nimbus data dir already initialised — skipping checkpoint sync";
+          exit 0;
+        fi;
+        /home/user/nimbus-eth2/build/nimbus_beacon_node trustedNodeSync \
+          --network=${NETWORK} \
+          --data-dir=/home/user/nimbus-eth2/build/data/${NETWORK} \
+          --trusted-node-url=${TRUSTED_NODE_URL} \
+          --backfill=false
+    restart: "no"
+
+  # One-shot: downloads a pre-synced snapshot from snapshots.reth.rs into the
+  # Reth data dir. Turns a multi-day from-scratch sync into a ~hour download.
+  # Skipped if the data dir is already initialised — re-runs are no-ops.
+  # Privacy note: snapshots.reth.rs sees this download (operator existence).
+  # Subsequent eth_call traffic stays local.
+  reth-snapshot-init:
+    image: ghcr.io/paradigmxyz/reth:latest
+    depends_on:
+      init:
+        condition: service_completed_successfully
+    volumes:
+      - reth-data:/data
+    entrypoint:
+      - sh
+      - -c
+      - |
+        if [ -f /data/.snapshot-done ] || [ -d /data/db ]; then
+          echo "Reth data already initialised — skipping snapshot download";
+          exit 0;
+        fi;
+        echo "Downloading Reth ${NETWORK} --minimal snapshot...";
+        reth download --datadir /data --chain ${NETWORK} --minimal && \
+        touch /data/.snapshot-done && \
+        echo "Snapshot download complete"
+    restart: "no"
+
+  reth:
+    image: ghcr.io/paradigmxyz/reth:latest
+    depends_on:
+      reth-snapshot-init:
+        condition: service_completed_successfully
+    volumes:
+      - reth-data:/data
+      - jwt:/jwt:ro
+    ports:
+      # JSON-RPC for smp-server. Bound to loopback — put Caddy in front for remote access.
+      - "127.0.0.1:8545:8545"
+      # p2p (Ethereum network). Open these on your firewall for sync.
+      - "30303:30303/tcp"
+      - "30303:30303/udp"
+    command: >
+      node
+      --datadir /data
+      --chain ${NETWORK}
+      --minimal
+      --authrpc.jwtsecret /jwt/jwt.hex
+      --authrpc.addr 0.0.0.0 --authrpc.port 8551
+      --http
+      --http.addr 0.0.0.0 --http.port 8545
+      --http.api eth,net
+      --rpc.gascap 50000000
+      --port 30303
+      --discovery.port 30303
+    restart: unless-stopped
+
+  nimbus:
+    image: statusim/nimbus-eth2:multiarch-latest
+    depends_on:
+      nimbus-checkpoint-sync:
+        condition: service_completed_successfully
+    volumes:
+      - nimbus-data:/home/user/nimbus-eth2/build/data
+      - jwt:/jwt:ro
+    ports:
+      - "9000:9000/tcp"
+      - "9000:9000/udp"
+      - "127.0.0.1:5052:5052"
+    command: >
+      --network=${NETWORK}
+      --data-dir=/home/user/nimbus-eth2/build/data/${NETWORK}
+      --el=http://reth:8551
+      --jwt-secret=/jwt/jwt.hex
+      --non-interactive
+      --rest --rest-address=0.0.0.0 --rest-port=5052
+      --nat=${NAT:-any}
+    restart: unless-stopped
+
+  # SNRC REST resolver. Talks to reth on the compose-internal network,
+  # exposes /resolve and /health on 127.0.0.1:8000 by default. The
+  # smp-server points its [NAMES] resolver_endpoint at this URL.
+  # To change the host port, edit the LEFT side of the port mapping below.
+  resolver:
+    build:
+      context: ./service
+      dockerfile: Dockerfile
+    depends_on:
+      # reth's `service_started` is sufficient — the resolver tolerates
+      # eth_call failures gracefully (returns 502 with the error body), so
+      # starting before reth has finished snapshot replay just yields a few
+      # 502s until the chain is queryable. The upstream reth image doesn't
+      # ship a HEALTHCHECK, so we can't gate on healthy.
+      reth:
+        condition: service_started
+    environment:
+      SNRC_RPC: http://reth:8545
+      SNRC_BIND: 0.0.0.0
+      # Registry addresses cascade through the script's own defaults
+      # (mainnet `.testing`; `.simplex` unconfigured). Set explicitly here
+      # only if you're deploying against a different network or contract.
+      # SNRC_REGISTRY_TESTING: 0x...
+      # SNRC_REGISTRY_SIMPLEX: 0x...
+    ports:
+      - "127.0.0.1:8000:8000"
+    restart: unless-stopped
+
+volumes:
+  reth-data:
+  nimbus-data:
+  jwt:
@@ -0,0 +1,48 @@
+# syntax=docker/dockerfile:1.7
+# ---------- builder ----------
+# Use the official uv image (Astral) on top of a slim Python base.
+# uv resolves and installs the lockfile-free pyproject.toml in seconds and
+# produces a portable .venv we can copy into the runtime stage.
+FROM ghcr.io/astral-sh/uv:python3.13-bookworm-slim AS builder
+
+ENV UV_LINK_MODE=copy \
+    UV_COMPILE_BYTECODE=1 \
+    UV_PYTHON_DOWNLOADS=never \
+    UV_NO_PROGRESS=1
+
+WORKDIR /app
+
+# Install deps first (separate layer) — script edits won't bust this cache.
+COPY pyproject.toml ./
+RUN --mount=type=cache,target=/root/.cache/uv \
+    uv sync --no-dev --no-install-project
+
+# Script is added after the dep layer for cache friendliness.
+COPY snrc-resolve.py ./
+
+# ---------- runtime ----------
+# Slim runtime — only the venv + script. No uv, no apt.
+FROM python:3.13-slim AS runtime
+
+ENV PYTHONUNBUFFERED=1 \
+    PYTHONDONTWRITEBYTECODE=1 \
+    PATH="/app/.venv/bin:$PATH"
+
+# Non-root user (matches resolver privacy posture: it has no need for root).
+RUN groupadd --system --gid 10001 snrc && \
+    useradd  --system --uid 10001 --gid snrc --no-create-home --shell /usr/sbin/nologin snrc
+
+WORKDIR /app
+COPY --from=builder --chown=snrc:snrc /app /app
+
+USER snrc:snrc
+
+EXPOSE 8000
+
+# Liveness check hits the script's own /health route. ThreadingHTTPServer is
+# fast enough that 3s is generous for a localhost probe; restart if it stops
+# responding entirely.
+HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
+    CMD ["python", "-c", "import urllib.request, sys; sys.exit(0 if urllib.request.urlopen('http://127.0.0.1:8000/health', timeout=3).status == 200 else 1)"]
+
+ENTRYPOINT ["python", "snrc-resolve.py"]
@@ -0,0 +1,13 @@
+[project]
+name = "snrc-resolve"
+version = "0.1.0"
+description = "SimpleX Namespace (SNRC) resolver — REST API over ENS-shaped Ethereum registries"
+readme = "README.md"
+requires-python = ">=3.11"
+license = "AGPL-3.0-only"
+dependencies = [
+  "eth-hash[pycryptodome]>=0.7",
+]
+
+[tool.uv]
+package = false
@@ -0,0 +1,517 @@
+#!/usr/bin/env python3
+# /// script
+# requires-python = ">=3.11"
+# dependencies = [
+#   "eth-hash[pycryptodome]>=0.7",
+# ]
+# ///
+"""SimpleX Namespace (SNRC) resolver — REST API.
+
+Resolves names like `alice.testing` / `bob.simplex` against the SNRC
+deployment on Ethereum mainnet (or any compatible ENS-shaped registry)
+and returns a flat JSON document with these fields:
+
+  name, nickname, website, location,
+  simplexContact, simplexChannel,    -- list[str], primary first
+  eth, btc, xmr, dot,
+  owner, resolver
+
+`simplexContact` and `simplexChannel` are arrays so a name can advertise
+multiple SMP servers for redundancy. Clients SHOULD try the URLs in the
+order returned. The on-chain text record stores them as a single
+`LINK_SEPARATOR` (`;`)-joined string; this resolver splits and trims into a list.
+
+All keys are valid Haskell record-field identifiers (lowercase initial,
+no dots), so consumers can derive aeson FromJSON instances directly
+without a key-rewriting layer.
+
+Usage:
+  ./snrc-resolve.py                    # serve on :8000
+
+  curl -s http://127.0.0.1:8000/resolve/foobar.testing | jq .
+  curl -s http://127.0.0.1:8000/health
+
+Environment:
+  SNRC_RPC               JSON-RPC endpoint (default: http://127.0.0.1:8545)
+  SNRC_REGISTRY_TESTING  ENSRegistry for the .testing deployment
+                         (default: mainnet,
+                          0x58fc46996d975c57883564648bda5206d1a0102b)
+  SNRC_REGISTRY_SIMPLEX  ENSRegistry for the .simplex deployment
+                         (default: empty — TLD not yet deployed)
+  SNRC_PORT              Listen port (default: 8000)
+  SNRC_BIND              Bind address (default: 0.0.0.0)
+
+Each TLD is a separate SNRC deployment with its own ENSRegistry; the
+resolver dispatches by the queried name's rightmost label.
+
+Dependencies are declared inline (PEP 723) at the top of this file. Run with:
+  uv run snrc-resolve.py          # uv resolves & caches deps; one-line setup
+  python snrc-resolve.py          # if eth-hash[pycryptodome] is already installed
+
+Addresses are returned in each chain's canonical presentation:
+  eth  EIP-55 mixed-case checksummed hex      (e.g. 0xEa65A0…1572)
+  btc  bech32(m) for segwit/taproot, base58check for P2PKH/P2SH
+       (e.g. bc1q…  /  1A1zP1…)
+  dot  SS58 with Polkadot network prefix 0    (e.g. 15oF4u…)
+  xmr  Monero base58                          (e.g. 4Aux5y…)
+Unrecognised payloads fall back to `0x`-prefixed raw hex.
+"""
+
+import hashlib
+import json
+import os
+import sys
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+from urllib.parse import unquote, urlparse
+from urllib.request import Request, urlopen
+
+from eth_hash.auto import keccak
+
+RPC = os.environ.get("SNRC_RPC", "http://127.0.0.1:8545")
+BIND = os.environ.get("SNRC_BIND", "0.0.0.0")
+PORT = int(os.environ.get("SNRC_PORT", "8000"))
+
+# Each TLD is its own SNRC deployment with its own ENSRegistry. Dispatch
+# happens on the rightmost label of the queried name. Empty / unset means
+# "not deployed" — requests for that TLD return 400 with a clear error.
+# `... or "..."` makes the script's defaults the single source of truth:
+# unset AND empty-string both fall through to the literal. docker-compose
+# can therefore pass `SNRC_REGISTRY_TESTING=${SNRC_REGISTRY_TESTING:-}`
+# without duplicating the registry address.
+REGISTRIES = {
+    "testing": os.environ.get("SNRC_REGISTRY_TESTING", "")
+    or "0x58fc46996d975c57883564648bda5206d1a0102b",  # mainnet .testing
+    "simplex": os.environ.get("SNRC_REGISTRY_SIMPLEX", ""),  # not deployed yet
+}
+
+# SLIP-44 coin types (https://github.com/satoshilabs/slips/blob/master/slip-0044.md)
+COIN_ETH = 60
+COIN_BTC = 0
+COIN_XMR = 128
+COIN_DOT = 354
+
+ZERO_ADDR = "0x0000000000000000000000000000000000000000"
+
+
+# ---------- RPC + ABI helpers (mirrors ens-lookup.py shape) ----------
+
+def rpc(method, params):
+    body = json.dumps(
+        {"jsonrpc": "2.0", "method": method, "params": params, "id": 1}
+    ).encode()
+    # Set a non-default User-Agent; Cloudflare-fronted public RPCs (drpc,
+    # publicnode, etc.) reject `Python-urllib/3.x` with 403.
+    req = Request(
+        RPC,
+        data=body,
+        headers={
+            "Content-Type": "application/json",
+            "User-Agent": "snrc-resolve/1.0",
+        },
+    )
+    res = json.loads(urlopen(req, timeout=15).read())
+    if "error" in res:
+        raise RuntimeError(res["error"])
+    return res["result"]
+
+
+def namehash(name: str) -> bytes:
+    node = b"\x00" * 32
+    if name:
+        for label in reversed(name.split(".")):
+            node = keccak(node + keccak(label.encode()))
+    return node
+
+
+def selector(signature: str) -> str:
+    return "0x" + keccak(signature.encode())[:4].hex()
+
+
+def eth_call(to: str, data: str) -> str:
+    return rpc("eth_call", [{"to": to, "data": data}, "latest"])
+
+
+def decode_address(hex_data: str) -> str:
+    return "0x" + hex_data[-40:]
+
+
+def decode_bytes(hex_data: str) -> bytes:
+    raw = bytes.fromhex(hex_data[2:] if hex_data.startswith("0x") else hex_data)
+    if len(raw) < 64:
+        return b""
+    length = int.from_bytes(raw[32:64], "big")
+    return raw[64:64 + length]
+
+
+def encode_text_call(node: bytes, key: str) -> str:
+    sel = selector("text(bytes32,string)")
+    head = node.hex() + (0x40).to_bytes(32, "big").hex()
+    key_bytes = key.encode()
+    body = len(key_bytes).to_bytes(32, "big").hex() + key_bytes.hex()
+    body += "00" * ((-len(key_bytes)) % 32)
+    return sel + head + body
+
+
+def text(resolver: str, node: bytes, key: str) -> str:
+    raw = decode_bytes(eth_call(resolver, encode_text_call(node, key)))
+    return raw.decode("utf-8", errors="replace") if raw else ""
+
+
+def encode_addr_multicoin_call(node: bytes, coin_type: int) -> str:
+    """ENSIP-9 addr(bytes32 node, uint256 coinType) — both static, no offsets."""
+    return (
+        selector("addr(bytes32,uint256)")
+        + node.hex()
+        + coin_type.to_bytes(32, "big").hex()
+    )
+
+
+def addr_multicoin(resolver: str, node: bytes, coin_type: int):
+    """Read ENSIP-9 raw bytes for `coinType`, then encode to that chain's
+    canonical presentation form. Falls back to `0x`-prefixed hex if the
+    payload doesn't match any recognised on-chain shape. Returns None when
+    the record is unset."""
+    try:
+        raw = decode_bytes(eth_call(resolver, encode_addr_multicoin_call(node, coin_type)))
+    except RuntimeError:
+        return None
+    if not raw:
+        return None
+    # An all-zero payload is the ENS convention for "unset" — many tools
+    # write 20 zero bytes for coinType=60 instead of clearing the slot.
+    # Treat it as null so the response doesn't surface a zero address.
+    if raw == b"\x00" * len(raw):
+        return None
+    encoder = COIN_ENCODERS.get(coin_type)
+    if encoder is None:
+        return "0x" + raw.hex()
+    try:
+        return encoder(raw) or ("0x" + raw.hex())
+    except Exception:
+        return "0x" + raw.hex()
+
+
+# ---------- Coin-specific address encoders ----------
+# Each takes raw bytes as stored under ENSIP-9 and returns the canonical
+# user-facing string for that chain (EIP-55 for ETH, bech32/base58check
+# for BTC, SS58 for DOT, Monero-base58 for XMR). All stdlib + eth_hash.
+
+
+B58_ALPHA = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
+
+
+def _b58_encode(b: bytes) -> str:
+    n = int.from_bytes(b, "big")
+    out = ""
+    while n:
+        n, r = divmod(n, 58)
+        out = B58_ALPHA[r] + out
+    # leading zero bytes → leading '1's
+    pad = len(b) - len(b.lstrip(b"\x00"))
+    return "1" * pad + out
+
+
+def _b58check_encode(payload: bytes) -> str:
+    """Base58Check used by BTC legacy/P2SH: payload + dSHA256(payload)[:4]."""
+    chk = hashlib.sha256(hashlib.sha256(payload).digest()).digest()[:4]
+    return _b58_encode(payload + chk)
+
+
+# ---- Bech32 / Bech32m (BIP-173 / BIP-350) ----
+
+_BECH32_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+_BECH32_GEN = [0x3B6A57B2, 0x26508E6D, 0x1EA119FA, 0x3D4233DD, 0x2A1462B3]
+
+
+def _bech32_polymod(values):
+    chk = 1
+    for v in values:
+        b = chk >> 25
+        chk = ((chk & 0x1FFFFFF) << 5) ^ v
+        for i in range(5):
+            if (b >> i) & 1:
+                chk ^= _BECH32_GEN[i]
+    return chk
+
+
+def _bech32_hrp_expand(hrp):
+    return [ord(c) >> 5 for c in hrp] + [0] + [ord(c) & 31 for c in hrp]
+
+
+def _bech32_create_checksum(hrp, data, spec):
+    const = 1 if spec == "bech32" else 0x2BC830A3  # bech32m
+    values = _bech32_hrp_expand(hrp) + data + [0] * 6
+    polymod = _bech32_polymod(values) ^ const
+    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
+
+
+def _bech32_encode(hrp, data, spec):
+    combined = data + _bech32_create_checksum(hrp, data, spec)
+    return hrp + "1" + "".join(_BECH32_CHARSET[d] for d in combined)
+
+
+def _convertbits(data, frombits, tobits, pad=True):
+    acc = 0
+    bits = 0
+    ret = []
+    maxv = (1 << tobits) - 1
+    max_acc = (1 << (frombits + tobits - 1)) - 1
+    for value in data:
+        if value < 0 or (value >> frombits):
+            return None
+        acc = ((acc << frombits) | value) & max_acc
+        bits += frombits
+        while bits >= tobits:
+            bits -= tobits
+            ret.append((acc >> bits) & maxv)
+    if pad and bits:
+        ret.append((acc << (tobits - bits)) & maxv)
+    elif not pad and (bits >= frombits or ((acc << (tobits - bits)) & maxv)):
+        return None
+    return ret
+
+
+def _segwit_encode(hrp: str, witver: int, witprog: bytes) -> str:
+    spec = "bech32" if witver == 0 else "bech32m"
+    data = [witver] + _convertbits(list(witprog), 8, 5)
+    return _bech32_encode(hrp, data, spec)
+
+
+# ---- BTC scriptPubKey → address ----
+# ENSIP-9 stores the raw output script. Dispatch by length + opcode prefix.
+
+def _btc_encode(raw: bytes) -> str | None:
+    hrp = "bc"  # mainnet
+    if len(raw) == 25 and raw[:3] == b"\x76\xa9\x14" and raw[23:25] == b"\x88\xac":
+        return _b58check_encode(b"\x00" + raw[3:23])  # P2PKH
+    if len(raw) == 23 and raw[:2] == b"\xa9\x14" and raw[22:23] == b"\x87":
+        return _b58check_encode(b"\x05" + raw[2:22])  # P2SH
+    if len(raw) == 22 and raw[:2] == b"\x00\x14":
+        return _segwit_encode(hrp, 0, raw[2:22])  # P2WPKH
+    if len(raw) == 34 and raw[:2] == b"\x00\x20":
+        return _segwit_encode(hrp, 0, raw[2:34])  # P2WSH
+    if len(raw) == 34 and raw[:2] == b"\x51\x20":
+        return _segwit_encode(hrp, 1, raw[2:34])  # P2TR
+    return None
+
+
+# ---- Polkadot SS58 ----
+# Per SS58 spec: base58( prefix_byte + pubkey + blake2b-512("SS58PRE" + body)[:2] )
+# Polkadot mainnet uses network prefix 0 (single byte); Kusama uses 2.
+
+_SS58_PRE = b"SS58PRE"
+
+
+def _ss58_encode(pubkey: bytes, network_prefix: int = 0) -> str:
+    if len(pubkey) != 32:
+        return None
+    body = bytes([network_prefix]) + pubkey
+    checksum = hashlib.blake2b(_SS58_PRE + body, digest_size=64).digest()[:2]
+    return _b58_encode(body + checksum)
+
+
+def _dot_encode(raw: bytes) -> str | None:
+    return _ss58_encode(raw, network_prefix=0)
+
+
+# ---- Monero base58 ----
+# Monero base58 encodes in 8-byte blocks; each full block → 11 chars, partial
+# block sizes per fixed table. Alphabet is identical to Bitcoin's.
+
+_XMR_BLOCK_SIZES = [0, 2, 3, 5, 6, 7, 9, 10, 11]
+
+
+def _xmr_encode(raw: bytes) -> str:
+    out = []
+    for i in range(0, len(raw), 8):
+        chunk = raw[i:i + 8]
+        n = int.from_bytes(chunk, "big")
+        width = 11 if len(chunk) == 8 else _XMR_BLOCK_SIZES[len(chunk)]
+        block = []
+        for _ in range(width):
+            n, r = divmod(n, 58)
+            block.append(B58_ALPHA[r])
+        out.append("".join(reversed(block)))
+    return "".join(out)
+
+
+# ---- ETH EIP-55 mixed-case checksum ----
+
+def _eth_encode(raw: bytes) -> str | None:
+    if len(raw) != 20:
+        return None
+    hex_addr = raw.hex()
+    hash_hex = keccak(hex_addr.encode()).hex()
+    return "0x" + "".join(
+        c.upper() if c.isalpha() and int(hash_hex[i], 16) >= 8 else c
+        for i, c in enumerate(hex_addr)
+    )
+
+
+COIN_ENCODERS = {
+    COIN_ETH: _eth_encode,
+    COIN_BTC: _btc_encode,
+    COIN_XMR: _xmr_encode,
+    COIN_DOT: _dot_encode,
+}
+
+
+# ---------- Resolution logic ----------
+
+# Text-record keys we read from the resolver. Surfaced under the response
+# field names listed in the docstring above. `name` and `description` are
+# common ENS fallbacks for a human-readable nickname.
+TEXT_KEYS = [
+    "name",
+    "nickname",
+    "description",
+    "url",
+    "location",
+    "simplex.contact",
+    "simplex.channel",
+]
+
+
+# Separator that joins the SMP-server URL list inside a simplex.contact /
+# simplex.channel text record. MUST match SIMPLEX_LINK_SEPARATOR in the dApp
+# (ens-app-v3 src/constants/simplex.ts) — the two sides decode the same record.
+LINK_SEPARATOR = ";"
+
+
+def split_links(value: str) -> list:
+    """Split a separator-joined text record into an ordered list of entries.
+
+    Trims whitespace around each element and drops empties so trailing
+    separators, doubled separators, and all-whitespace inputs all yield clean
+    output. Single-value records yield a 1-element list; empty inputs
+    yield `[]`. Used for `simplex.contact` / `simplex.channel`, which
+    store one-or-more SMP-server URLs as a single `LINK_SEPARATOR`-joined string.
+    """
+    return [item.strip() for item in value.split(LINK_SEPARATOR) if item.strip()]
+
+
+def resolve(name: str):
+    tld = name.rsplit(".", 1)[-1]
+    registry = REGISTRIES.get(tld)
+    if not registry:
+        configured = [k for k, v in REGISTRIES.items() if v]
+        return 400, {
+            "name": name,
+            "error": f"TLD '{tld}' is not configured on this resolver",
+            "configured_tlds": configured,
+        }
+
+    node = namehash(name)
+    node_hex = node.hex()
+
+    resolver_raw = eth_call(registry, selector("resolver(bytes32)") + node_hex)
+    resolver_addr = decode_address(resolver_raw)
+    if resolver_addr == ZERO_ADDR:
+        return 404, {"name": name, "error": "no resolver set for this name"}
+
+    owner_raw = eth_call(registry, selector("owner(bytes32)") + node_hex)
+    owner = decode_address(owner_raw)
+
+    texts = {}
+    for k in TEXT_KEYS:
+        try:
+            v = text(resolver_addr, node, k)
+        except RuntimeError:
+            v = ""
+        if v:
+            texts[k] = v
+
+    # The user-facing "nickname" prefers an explicit `nickname` record,
+    # falls back to `name`, then `description` (ENSIP-5 convention).
+    nickname = texts.get("nickname") or texts.get("name") or texts.get("description") or ""
+
+    # Keys chosen to be valid Haskell record-field identifiers (lowercase
+    # initial, no dots) so consumers can derive aeson FromJSON instances
+    # without a key-rewriting layer. On-chain text-record names still
+    # use the ENSIP-5 dot convention (e.g. "simplex.contact") — only the
+    # resolver's JSON surface camelCases them.
+    return 200, {
+        "name": name,
+        "nickname": nickname,
+        "website": texts.get("url", ""),
+        "location": texts.get("location", ""),
+        "simplexContact": split_links(texts.get("simplex.contact", "")),
+        "simplexChannel": split_links(texts.get("simplex.channel", "")),
+        "eth": addr_multicoin(resolver_addr, node, COIN_ETH),
+        "btc": addr_multicoin(resolver_addr, node, COIN_BTC),
+        "xmr": addr_multicoin(resolver_addr, node, COIN_XMR),
+        "dot": addr_multicoin(resolver_addr, node, COIN_DOT),
+        "owner": owner,
+        "resolver": resolver_addr,
+    }
+
+
+# ---------- HTTP layer ----------
+
+class Handler(BaseHTTPRequestHandler):
+    def do_GET(self):  # noqa: N802 - http.server contract
+        path = urlparse(self.path).path
+        parts = [unquote(p) for p in path.split("/") if p]
+
+        if parts == ["health"]:
+            self._respond(
+                200,
+                {"ok": True, "rpc": RPC, "registries": REGISTRIES},
+            )
+            return
+
+        if len(parts) == 2 and parts[0] == "resolve":
+            name = parts[1].strip().lower()
+            if not name or "." not in name:
+                self._respond(
+                    400,
+                    {
+                        "error": "expected fully-qualified name, e.g. /resolve/alice.testing",
+                        "got": name,
+                    },
+                )
+                return
+            try:
+                status, body = resolve(name)
+            except Exception as e:  # surface upstream errors as 502
+                status, body = 502, {"name": name, "error": f"{type(e).__name__}: {e}"}
+            self._respond(status, body)
+            return
+
+        self._respond(
+            404,
+            {"error": "not found", "routes": ["/health", "/resolve/<name>"]},
+        )
+
+    def _respond(self, status: int, body: dict):
+        data = json.dumps(body, indent=2).encode()
+        self.send_response(status)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(data)))
+        self.end_headers()
+        self.wfile.write(data)
+
+    def log_message(self, fmt, *args):
+        # Quiet the default per-request access log; route to stderr in one line.
+        sys.stderr.write(f"{self.address_string()} - {fmt % args}\n")
+
+
+def main():
+    server = ThreadingHTTPServer((BIND, PORT), Handler)
+    sys.stderr.write(
+        f"snrc-resolve listening on {BIND}:{PORT}\n"
+        f"  RPC = {RPC}\n"
+        f"  Registries:\n"
+    )
+    for tld, addr in REGISTRIES.items():
+        sys.stderr.write(f"    .{tld:<8s} = {addr or '(not configured)'}\n")
+    sys.stderr.write("  GET /resolve/<name>   GET /health\n")
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        sys.stderr.write("\nshutting down\n")
+        server.server_close()
+
+
+if __name__ == "__main__":
+    main()
@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+"""Unit tests for snrc-resolve helpers.
+
+Run with `python3 -m unittest scripts/resolver/service/test_snrc_resolve.py`.
+"""
+
+import importlib.util
+import os
+import unittest
+
+# snrc-resolve.py has a hyphen, so import it via importlib instead of `import`.
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_SPEC = importlib.util.spec_from_file_location(
+    "snrc_resolve", os.path.join(_HERE, "snrc-resolve.py")
+)
+snrc = importlib.util.module_from_spec(_SPEC)
+_SPEC.loader.exec_module(snrc)
+
+
+class SplitLinksTests(unittest.TestCase):
+    """`split_links` decodes the multi-URL convention for simplex.contact /
+    simplex.channel text records. Reuses the same rule the dApp's
+    `parseSimplexUrls` uses (separator `;`), so the two sides round-trip
+    cleanly."""
+
+    def test_empty_string_yields_empty_list(self):
+        self.assertEqual(snrc.split_links(""), [])
+
+    def test_whitespace_only_yields_empty_list(self):
+        self.assertEqual(snrc.split_links("   "), [])
+        self.assertEqual(snrc.split_links(" ; ; "), [])
+
+    def test_single_url_yields_singleton_list(self):
+        self.assertEqual(
+            snrc.split_links("https://smp16.simplex.im/a#H1"),
+            ["https://smp16.simplex.im/a#H1"],
+        )
+
+    def test_two_urls_split_on_separator(self):
+        self.assertEqual(
+            snrc.split_links(
+                "https://smp16.simplex.im/a#H1;https://smp19.simplex.im/a#H1"
+            ),
+            [
+                "https://smp16.simplex.im/a#H1",
+                "https://smp19.simplex.im/a#H1",
+            ],
+        )
+
+    def test_whitespace_around_separators_is_trimmed(self):
+        self.assertEqual(
+            snrc.split_links(
+                "  https://smp16.simplex.im/a#H1 ;\thttps://smp19.simplex.im/a#H1 "
+            ),
+            [
+                "https://smp16.simplex.im/a#H1",
+                "https://smp19.simplex.im/a#H1",
+            ],
+        )
+
+    def test_trailing_separator_does_not_produce_empty_entry(self):
+        self.assertEqual(
+            snrc.split_links("https://smp16.simplex.im/a#H1;"),
+            ["https://smp16.simplex.im/a#H1"],
+        )
+
+    def test_doubled_separator_does_not_produce_empty_entry(self):
+        self.assertEqual(
+            snrc.split_links(
+                "https://smp16.simplex.im/a#H1;;https://smp19.simplex.im/a#H1"
+            ),
+            [
+                "https://smp16.simplex.im/a#H1",
+                "https://smp19.simplex.im/a#H1",
+            ],
+        )
+
+    def test_order_is_preserved(self):
+        self.assertEqual(
+            snrc.split_links("c;a;b"),
+            ["c", "a", "b"],
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()
@@ -0,0 +1,168 @@
+#!/usr/bin/env python3
+"""Resolve an ENS name via local Reth (the same shape SNRC will use).
+
+Usage:
+  ./ens-lookup.py                     # defaults to simplexchat.eth
+  ./ens-lookup.py vitalik.eth
+  ./ens-lookup.py corevo.eth
+
+Requires:  pip install --break-system-packages 'eth-hash[pycryptodome]'
+"""
+
+import base64
+import json
+import sys
+from urllib.request import Request, urlopen
+
+from eth_hash.auto import keccak
+
+RPC = "http://127.0.0.1:8545"
+# ENS Registry (current, post-2020 migration)
+ENS_REGISTRY = "0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e"
+
+
+def rpc(method, params):
+    body = json.dumps({"jsonrpc": "2.0", "method": method, "params": params, "id": 1}).encode()
+    req = Request(RPC, data=body, headers={"Content-Type": "application/json"})
+    res = json.loads(urlopen(req, timeout=15).read())
+    if "error" in res:
+        raise RuntimeError(res["error"])
+    return res["result"]
+
+
+def namehash(name: str) -> bytes:
+    """ENS namehash — recursive keccak256 over reversed labels."""
+    node = b"\x00" * 32
+    if name:
+        for label in reversed(name.split(".")):
+            node = keccak(node + keccak(label.encode()))
+    return node
+
+
+def selector(signature: str) -> str:
+    return "0x" + keccak(signature.encode())[:4].hex()
+
+
+def eth_call(to: str, data: str) -> str:
+    return rpc("eth_call", [{"to": to, "data": data}, "latest"])
+
+
+def decode_address(hex_data: str) -> str:
+    return "0x" + hex_data[-40:]
+
+
+def decode_bytes(hex_data: str) -> bytes:
+    raw = bytes.fromhex(hex_data[2:] if hex_data.startswith("0x") else hex_data)
+    if len(raw) < 64:
+        return b""
+    length = int.from_bytes(raw[32:64], "big")
+    return raw[64:64 + length]
+
+
+def encode_text_call(node: bytes, key: str) -> str:
+    """ABI-encode text(bytes32 node, string key). String arg is dynamic:
+    offset (=0x40) + length + right-padded data."""
+    sel = selector("text(bytes32,string)")
+    head = node.hex() + (0x40).to_bytes(32, "big").hex()
+    key_bytes = key.encode()
+    body = len(key_bytes).to_bytes(32, "big").hex() + key_bytes.hex()
+    # right-pad to 32-byte boundary
+    pad = (-len(key_bytes)) % 32
+    body += "00" * pad
+    return sel + head + body
+
+
+def text(resolver: str, node: bytes, key: str) -> str:
+    raw = decode_bytes(eth_call(resolver, encode_text_call(node, key)))
+    return raw.decode("utf-8", errors="replace") if raw else ""
+
+
+# Common ENS text keys (ENSIP-5). Resolvers may return empty for any of these.
+TEXT_KEYS = [
+    "url",
+    "avatar",
+    "description",
+    "email",
+    "notice",
+    "keywords",
+    "com.twitter",
+    "com.github",
+    "com.discord",
+    "org.telegram",
+    "io.keybase",
+    "xyz.farcaster",
+]
+
+
+def decode_contenthash(raw: bytes) -> str:
+    """ENS contenthash → human-readable URI (best-effort)."""
+    if not raw:
+        return "(empty)"
+    # Multicodec prefixes:
+    #   0xe301 = ipfs-ns + dag-pb (CIDv0/v1)
+    #   0xe501 = ipns-ns
+    #   0xe40101701b... = swarm
+    if raw[:2] == b"\xe3\x01":
+        cid_bytes = raw[2:]
+        # Base32 lowercase + 'b' prefix per CIDv1 spec
+        b32 = base64.b32encode(cid_bytes).decode().lower().rstrip("=")
+        return f"ipfs://b{b32}"
+    if raw[:2] == b"\xe5\x01":
+        cid_bytes = raw[2:]
+        b32 = base64.b32encode(cid_bytes).decode().lower().rstrip("=")
+        return f"ipns://b{b32}"
+    return "0x" + raw.hex()
+
+
+def main():
+    name = sys.argv[1] if len(sys.argv) > 1 else "simplexchat.eth"
+
+    print(f"  name:       {name}")
+    node = namehash(name)
+    print(f"  namehash:   0x{node.hex()}")
+
+    # 1. Ask the registry which resolver is responsible for this name
+    resolver_data = selector("resolver(bytes32)") + node.hex()
+    resolver_raw = eth_call(ENS_REGISTRY, resolver_data)
+    resolver = decode_address(resolver_raw)
+    print(f"  resolver:   {resolver}")
+    if resolver == "0x0000000000000000000000000000000000000000":
+        print("  → no resolver set for this name")
+        return
+
+    node_hex = node.hex()
+
+    # 2. Ask the resolver for the address
+    try:
+        addr = decode_address(eth_call(resolver, selector("addr(bytes32)") + node_hex))
+        print(f"  address:    {addr}")
+    except Exception as e:
+        print(f"  address:    (error: {e})")
+
+    # 3. Ask the resolver for the content hash (IPFS pointer)
+    try:
+        ch = decode_bytes(eth_call(resolver, selector("contenthash(bytes32)") + node_hex))
+        print(f"  contenthash: {decode_contenthash(ch)}")
+    except Exception as e:
+        print(f"  contenthash: (not supported: {e})")
+
+    # 4. Owner from the registry
+    try:
+        owner = decode_address(eth_call(ENS_REGISTRY, selector("owner(bytes32)") + node_hex))
+        print(f"  owner:      {owner}")
+    except Exception as e:
+        print(f"  owner:      (error: {e})")
+
+    # 5. Text records (EIP-634). Print only the non-empty ones.
+    print("  text records:")
+    for key in TEXT_KEYS:
+        try:
+            v = text(resolver, node, key)
+            if v:
+                print(f"    {key:<16s} {v}")
+        except Exception as e:
+            print(f"    {key:<16s} (error: {e})")
+
+
+if __name__ == "__main__":
+    main()
@@ -0,0 +1,246 @@
+#!/usr/bin/env python3
+"""Sync progress for the Reth + Nimbus stack.
+
+Usage:
+  ./progress.py           # continuous (Ctrl-C to exit, auto-exits when synced)
+  ./progress.py --once    # single snapshot
+
+Requires Nimbus REST port exposed at 127.0.0.1:5052 (add --rest flag in compose).
+"""
+
+import json
+import sys
+import time
+from collections import deque
+from datetime import timedelta
+from urllib.error import URLError
+from urllib.request import Request, urlopen
+
+RETH = "http://127.0.0.1:8545"
+NIMBUS = "http://127.0.0.1:5052"
+INTERVAL = 5
+WINDOW = 60
+BAR_W = 40
+
+# ANSI helpers
+def c(s, code): return f"\033[{code}m{s}\033[0m"
+GREEN, YELLOW, RED, DIM, BOLD = "32", "33", "31", "2;37", "1"
+
+
+def rpc(method):
+    body = json.dumps({"jsonrpc": "2.0", "method": method, "params": [], "id": 1}).encode()
+    req = Request(RETH, data=body, headers={"Content-Type": "application/json"})
+    return json.loads(urlopen(req, timeout=5).read())["result"]
+
+
+def get_reth():
+    try:
+        r = rpc("eth_syncing")
+        try:
+            peers = int(rpc("net_peerCount"), 16)
+        except Exception:
+            peers = -1            # net namespace not exposed
+        if r is False:
+            head = int(rpc("eth_blockNumber"), 16)
+            return {"state": "synced", "current": head, "target": head, "peers": peers,
+                    "stage": None, "stages": {}, "err": None}
+        current = int(r["currentBlock"], 16)
+        highest = int(r["highestBlock"], 16)
+        # Build stage map (name -> block).
+        stages = {s["name"]: int(s["block"], 16) for s in r.get("stages", [])}
+        active_stages = {k: v for k, v in stages.items() if v > 0}
+        # Headers download phase: nothing has progressed yet.
+        if current == 0 and highest == 0 and not active_stages:
+            return {"state": "headers", "current": 0, "target": 0, "peers": peers,
+                    "stage": "Headers", "stages": stages, "err": None}
+        # Derive progress from the stages pipeline.
+        # Bottleneck (rate-limiting stage) = stage with lowest non-zero block.
+        # Target = leading stage block (typically Headers = chain tip).
+        # Reth's top-level currentBlock/highestBlock are unreliable during initial
+        # sync (often 0 until execution stage runs), so prefer stages-derived values.
+        if active_stages:
+            bottleneck = min(active_stages, key=active_stages.get)
+            stage_current = active_stages[bottleneck]
+            stage_target = max(stages.values()) if stages else 0
+            # Trust the stages-derived values if highest is unset or stages tip is higher.
+            if highest <= 0 or stage_target > highest:
+                current = stage_current
+                highest = stage_target
+            elif current <= 0:
+                current = stage_current
+        else:
+            bottleneck = None
+        return {"state": "syncing", "current": current, "target": highest,
+                "peers": peers, "stage": bottleneck, "stages": stages, "err": None}
+    except URLError as e:
+        return {"state": "down", "current": 0, "target": 0, "peers": 0,
+                "stage": None, "stages": {}, "err": str(e.reason)}
+    except Exception as e:
+        return {"state": "error", "current": 0, "target": 0, "peers": 0,
+                "stage": None, "stages": {}, "err": str(e)}
+
+
+def get_nimbus():
+    try:
+        d = json.loads(urlopen(f"{NIMBUS}/eth/v1/node/syncing", timeout=5).read())["data"]
+        peers_d = json.loads(urlopen(f"{NIMBUS}/eth/v1/node/peer_count", timeout=5).read())["data"]
+        head = int(d["head_slot"])
+        dist = int(d["sync_distance"])
+        peers = int(peers_d.get("connected", "0"))
+        return {"state": "synced" if not d["is_syncing"] else "syncing",
+                "current": head, "target": head + dist, "peers": peers,
+                "optimistic": bool(d.get("is_optimistic", False)),
+                "el_offline": bool(d.get("el_offline", False)),
+                "err": None}
+    except URLError as e:
+        return {"state": "down", "current": 0, "target": 0, "peers": 0,
+                "optimistic": False, "el_offline": False, "err": str(e.reason)}
+    except Exception as e:
+        return {"state": "error", "current": 0, "target": 0, "peers": 0,
+                "optimistic": False, "el_offline": False, "err": str(e)}
+
+
+def format_num(n): return f"{n:,}"
+
+
+def format_eta(seconds):
+    if seconds is None: return "?"
+    if seconds < 0: return "?"
+    if seconds < 60: return f"{int(seconds)}s"
+    if seconds < 3600:
+        return f"{int(seconds // 60)}m {int(seconds % 60)}s"
+    if seconds < 86400:
+        return f"{int(seconds // 3600)}h {int((seconds % 3600) // 60)}m"
+    return f"{int(seconds // 86400)}d {int((seconds % 86400) // 3600)}h"
+
+
+def rate_per_sec(history):
+    if len(history) < 2: return None
+    t0, c0 = history[0]
+    t1, c1 = history[-1]
+    if t1 <= t0: return None
+    return (c1 - c0) / (t1 - t0)
+
+
+def eta_seconds(history, target):
+    r = rate_per_sec(history)
+    if r is None or r <= 0: return None
+    remaining = target - history[-1][1]
+    if remaining <= 0: return 0
+    return remaining / r
+
+
+def progress_bar(pct):
+    pct = max(0.0, min(100.0, pct))
+    filled = int(pct / 100 * BAR_W)
+    return c("█" * filled, GREEN) + c("░" * (BAR_W - filled), DIM)
+
+
+def peers_label(peers):
+    if peers < 0:
+        return c("· peers unknown (enable net namespace)", DIM)
+    return c(f"· {peers} peers", DIM)
+
+
+def stages_summary(stages):
+    """One-line view: stages that have progressed, with their block numbers."""
+    if not stages:
+        return ""
+    advanced = [(n, b) for n, b in stages.items() if b > 0]
+    if not advanced:
+        return c("  stages: all 0 (headers downloading)", DIM)
+    advanced.sort(key=lambda kv: kv[1], reverse=True)
+    parts = [f"{n}={format_num(b)}" for n, b in advanced[:4]]
+    return c("  stages: " + ", ".join(parts), DIM)
+
+
+def render_one(name, x, hist):
+    state = x["state"]
+    peers = x.get("peers", 0)
+    extras = []
+    if name == "Nimbus":
+        if x.get("optimistic"):
+            extras.append(c("(optimistic head — Reth not yet verifying)", YELLOW))
+        if x.get("el_offline"):
+            extras.append(c("⚠ EL OFFLINE", RED))
+    if state == "synced":
+        out = [f"  {c(name, BOLD):<14s} {c('✓ synced', GREEN)}      {c(format_num(x['current']), BOLD)}  {peers_label(peers)}"]
+    elif state == "headers":
+        out = [
+            f"  {c(name, BOLD):<14s} {c('⧗ headers', YELLOW)}    {c('downloading initial chain', DIM)}  {peers_label(peers)}",
+            f"                 {c('(per-block progress unavailable until headers validated — see docker logs)', DIM)}",
+        ]
+    elif state == "syncing" and x["target"] <= 0:
+        out = [f"  {c(name, BOLD):<14s} {c('⧗ syncing', YELLOW)}    {c('waiting for fork-choice', DIM)}  {peers_label(peers)}"]
+    elif state == "syncing":
+        pct = x["current"] / x["target"] * 100
+        r = rate_per_sec(hist)
+        eta = eta_seconds(hist, x["target"])
+        rate_s = f"{format_num(int(r))} /s" if r and r > 0 else c("stalled", RED)
+        eta_s = format_eta(eta) if eta is not None else "?"
+        stage = x.get("stage")
+        stage_s = c(f"[{stage}]", DIM) if stage else ""
+        out = [
+            f"  {c(name, BOLD):<14s} {c('⧗ syncing', YELLOW)}    {format_num(x['current'])} / {format_num(x['target'])}  {stage_s}  {peers_label(peers)}",
+            f"                 {progress_bar(pct)} {c(f'{pct:6.2f}%', BOLD)}",
+            f"                 {c(rate_s, DIM)}   ETA {c(eta_s, BOLD)}",
+        ]
+    else:
+        out = [
+            f"  {c(name, BOLD):<14s} {c('✗ ' + state, RED)}",
+            f"                 {c(x.get('err') or '', DIM)}",
+        ]
+    # Reth-only: stages summary
+    if name == "Reth" and x.get("stages"):
+        out.append(f"               {stages_summary(x['stages'])}")
+    for e in extras:
+        out.append(f"                 {e}")
+    return out
+
+
+def render(reth, nimbus, reth_hist, nim_hist):
+    print("\033[2J\033[H", end="")
+    width = 64
+    title = f"Reth + Nimbus sync"
+    ts = time.strftime("%H:%M:%S")
+    print()
+    print(f"  {c(title, BOLD)}   {c(ts, DIM)}")
+    print(f"  {c('─' * width, DIM)}")
+    print()
+    for line in render_one("Reth", reth, reth_hist):
+        print(line)
+    print()
+    for line in render_one("Nimbus", nimbus, nim_hist):
+        print(line)
+    print()
+    win_s = (len(reth_hist) - 1) * INTERVAL if len(reth_hist) > 1 else 0
+    print(f"  {c(f'window {win_s}s · refresh {INTERVAL}s · Ctrl-C to exit', DIM)}")
+    print()
+
+
+def main():
+    once = "--once" in sys.argv
+    reth_hist = deque(maxlen=WINDOW)
+    nim_hist = deque(maxlen=WINDOW)
+    try:
+        while True:
+            r = get_reth()
+            n = get_nimbus()
+            now = time.time()
+            if r["target"] > 0 or r["state"] == "syncing":
+                reth_hist.append((now, r["current"]))
+            if n["target"] > 0 or n["state"] == "syncing":
+                nim_hist.append((now, n["current"]))
+            render(r, n, reth_hist, nim_hist)
+            if once:
+                break
+            if r["state"] == "synced" and n["state"] == "synced":
+                print(f"  {c('✓ all synced.', GREEN)}\n")
+                break
+            time.sleep(INTERVAL)
+    except KeyboardInterrupt:
+        print()
+
+
+if __name__ == "__main__":
+    main()
@@ -22,7 +22,7 @@ smp-server --version

 # Initialize server
 ip_address=$(curl ifconfig.me)
-smp-server init -l --ip $ip_address
+smp-server init -l --disable-web --ip $ip_address

 # Server fingerprint
 fingerprint=$(cat /etc/opt/simplex/fingerprint)
@@ -12,6 +12,11 @@ Check SMP server status with: systemctl status smp-server
 To keep this server secure, the UFW firewall is enabled.
 All ports are BLOCKED except 22 (SSH), 443 (HTTPS), 5223 (SMP server).

+Embedded HTTPS web is disabled because this image does not provision
+/etc/opt/simplex/web.crt or /etc/opt/simplex/web.key. To enable it, provision
+those files, uncomment WEB https/cert/key in /etc/opt/simplex/smp-server.ini,
+and restart smp-server.
+
 ********************************************************************************
 To stop seeing this message delete line - bash /opt/simplex/on_login.sh - from /root/.bashrc
 EOF
@@ -75,6 +75,9 @@ init_opts=()

 [[ $ENABLE_STORE_LOG == "on" ]] && init_opts+=(-l)

+# This script does not provision /etc/opt/simplex/web.crt or web.key.
+init_opts+=(--disable-web)
+
 ip_address=$(curl ifconfig.me)
 init_opts+=(--ip $ip_address)

@@ -111,6 +114,11 @@ Check SMP server status with: systemctl status smp-server
 To keep this server secure, the UFW firewall is enabled.
 All ports are BLOCKED except 22 (SSH), 443 (HTTPS), 5223 (SMP server).

+Embedded HTTPS web is disabled because this script does not provision
+/etc/opt/simplex/web.crt or /etc/opt/simplex/web.key. To enable it, provision
+those files, uncomment WEB https/cert/key in /etc/opt/simplex/smp-server.ini,
+and restart smp-server.
+
 ********************************************************************************
 To stop seeing this message delete line - bash /opt/simplex/on_login.sh - from /root/.bashrc
 EOF2
@@ -1,7 +1,7 @@
-cabal-version: 1.12
+cabal-version: 3.0

 name:           simplexmq
-version:        6.5.0.11
+version:        7.1.0.4
 synopsis:       SimpleXMQ message broker
 description:    This package includes <./docs/Simplex-Messaging-Server.html server>,
                <./docs/Simplex-Messaging-Client.html client> and
@@ -16,7 +16,7 @@ homepage:       https://github.com/simplex-chat/simplexmq#readme
 author:         simplex.chat
 maintainer:     chat@simplex.chat
 copyright:      2020-2022 simplex.chat
-license:        AGPL-3
+license:        AGPL-3.0-only
 license-file:   LICENSE
 build-type:     Simple
 extra-source-files:
@@ -24,6 +24,13 @@ extra-source-files:
    CHANGELOG.md
    cbits/sha512.h
    cbits/sntrup761.h
+    cbits/blst/**/*.c
+    cbits/blst/**/*.h
+    cbits/blst/**/*.s
+    cbits/blst/**/*.S
+    cbits/blst/**/*.asm
+    cbits/libbbs/**/*.c
+    cbits/libbbs/**/*.h
    apps/common/Web/static/index.html
    apps/common/Web/static/link.html
    apps/common/Web/static/media/apk_icon.png
@@ -82,6 +89,11 @@ flag server_postgres
  manual: True
  default: False

+flag commoncrypto
+  description: On Apple platforms, use SecRandomCopyBytes (Security.framework) for libbbs randomness. getentropy is a non-public symbol on iOS and triggers App Store rejection (ITMS-90338).
+  manual: True
+  default: False
+
 library
  exposed-modules:
      Simplex.FileTransfer.Agent
@@ -122,6 +134,7 @@ library
      Simplex.Messaging.Crypto.File
      Simplex.Messaging.Crypto.Lazy
      Simplex.Messaging.Crypto.Ratchet
+      Simplex.Messaging.Crypto.BBS
      Simplex.Messaging.Crypto.SNTRUP761
      Simplex.Messaging.Crypto.SNTRUP761.Bindings
      Simplex.Messaging.Crypto.SNTRUP761.Bindings.Defines
@@ -130,6 +143,7 @@ library
      Simplex.Messaging.Crypto.ShortLink
      Simplex.Messaging.Encoding
      Simplex.Messaging.Encoding.String
+      Simplex.Messaging.Names.Record
      Simplex.Messaging.Notifications.Client
      Simplex.Messaging.Notifications.Protocol
      Simplex.Messaging.Notifications.Transport
@@ -138,9 +152,11 @@ library
      Simplex.Messaging.Protocol
      Simplex.Messaging.Protocol.Types
      Simplex.Messaging.Server.Expiration
+      Simplex.Messaging.Server.Information
      Simplex.Messaging.Server.QueueStore.Postgres.Config
      Simplex.Messaging.Server.QueueStore.QueueInfo
      Simplex.Messaging.ServiceScheme
+      Simplex.Messaging.SimplexName
      Simplex.Messaging.Session
      Simplex.Messaging.SystemTime
      Simplex.Messaging.TMap
@@ -173,7 +189,9 @@ library
          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251009_queue_to_subscribe
          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251010_client_notices
          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251230_strict_tables
-          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260115_service_certs
+          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260410_receive_attempts
+          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260411_service_certs
+          Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260712_address_dr_rpc
  else
      exposed-modules:
          Simplex.Messaging.Agent.Store.SQLite
@@ -224,7 +242,9 @@ library
          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251009_queue_to_subscribe
          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251010_client_notices
          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251230_strict_tables
-          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260115_service_certs
+          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260410_receive_attempts
+          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260411_service_certs
+          Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260712_address_dr_rpc
          Simplex.Messaging.Agent.Store.SQLite.Util
  if flag(client_postgres) || flag(server_postgres)
      exposed-modules:
@@ -249,7 +269,6 @@ library
          Simplex.Messaging.Server.CLI
          Simplex.Messaging.Server.Control
          Simplex.Messaging.Server.Env.STM
-          Simplex.Messaging.Server.Information
          Simplex.Messaging.Server.Main
          Simplex.Messaging.Server.Main.GitCommit
          Simplex.Messaging.Server.Main.Init
@@ -259,6 +278,8 @@ library
          Simplex.Messaging.Server.MsgStore.Journal.SharedLock
          Simplex.Messaging.Server.MsgStore.STM
          Simplex.Messaging.Server.MsgStore.Types
+          Simplex.Messaging.Server.Names
+          Simplex.Messaging.Server.Names.HttpResolver
          Simplex.Messaging.Server.NtfStore
          Simplex.Messaging.Server.Prometheus
          Simplex.Messaging.Server.QueueStore
@@ -283,6 +304,9 @@ library
              Simplex.Messaging.Notifications.Server.Store.Migrations
              Simplex.Messaging.Notifications.Server.Store.Postgres
              Simplex.Messaging.Notifications.Server.Store.Types
+              Simplex.FileTransfer.Server.Store.Postgres
+              Simplex.FileTransfer.Server.Store.Postgres.Config
+              Simplex.FileTransfer.Server.Store.Postgres.Migrations
              Simplex.Messaging.Server.MsgStore.Postgres
              Simplex.Messaging.Server.QueueStore.Postgres
              Simplex.Messaging.Server.QueueStore.Postgres.Migrations
@@ -295,11 +319,33 @@ library
  ghc-options: -Weverything -Wno-missing-exported-signatures -Wno-missing-import-lists -Wno-missed-specialisations -Wno-all-missed-specialisations -Wno-unsafe -Wno-safe -Wno-missing-local-signatures -Wno-missing-kind-signatures -Wno-missing-deriving-strategies -Wno-monomorphism-restriction -Wno-prepositive-qualified-module -Wno-implicit-prelude -Wno-missing-safe-haskell-mode -Wno-missing-export-lists -Wno-partial-fields -Wcompat -Werror=incomplete-record-updates -Werror=incomplete-patterns -Werror=incomplete-uni-patterns -Werror=missing-home-modules -Werror=missing-methods -Werror=tabs -Wredundant-constraints -Wincomplete-record-updates -Wunused-type-patterns -O2
  include-dirs:
      cbits
+      cbits/blst/bindings
+      cbits/blst/src
+      cbits/libbbs/include
+      cbits/libbbs/src
+  cc-options: -D__BLST_PORTABLE__
+  if flag(commoncrypto)
+    cc-options: -DBBS_CRYPTO_CC
+    frameworks: Security
  c-sources:
      cbits/sha512.c
      cbits/sntrup761.c
+      cbits/blst/src/server.c
+      cbits/libbbs/src/bbs.c
+      cbits/libbbs/src/bbs_ciphersuites.c
+      cbits/libbbs/src/bbs_util.c
+      cbits/libbbs/src/compat-string.c
+      cbits/libbbs/src/sha256.c
+      cbits/libbbs/src/shake256.c
+  asm-sources:
+      cbits/blst/build/assembly.S
  extra-libraries:
      crypto
+  if os(windows)
+    c-sources:
+        cbits/getentropy_win.c
+    extra-libraries:
+        bcrypt
  build-depends:
      aeson ==2.2.*
    , asn1-encoding ==0.9.*
@@ -350,7 +396,10 @@ library
    build-depends:
        case-insensitive ==1.2.*
      , hashable ==1.4.*
+      , http-client >=0.7 && <0.8
+      , http-client-tls >=0.3 && <0.4
      , ini ==0.4.1
+      , network-uri >=2.6 && <2.7
      , optparse-applicative >=0.15 && <0.17
      , process ==1.6.*
      , temporary ==1.3.*
@@ -432,36 +481,6 @@ executable smp-server
    , text
  default-language: Haskell2010

-executable smp-server-bench
-  if flag(client_library)
-      buildable: False
-  if flag(server_postgres)
-    cpp-options: -DdbServerPostgres
-  main-is: Main.hs
-  other-modules:
-      ClientSim
-      Report
-  hs-source-dirs:
-      bench
-  default-extensions:
-      StrictData
-  ghc-options: -O2 -threaded -rtsopts
-  build-depends:
-      base
-    , async
-    , bytestring
-    , containers
-    , crypton
-    , mtl
-    , network
-    , simple-logger
-    , simplexmq
-    , stm
-    , text
-    , time
-    , unliftio
-  default-language: Haskell2010
-
 executable xftp
  if flag(client_library)
      buildable: False
@@ -514,6 +533,7 @@ test-suite simplexmq-test
      AgentTests.EqInstances
      AgentTests.FunctionalAPITests
      AgentTests.MigrationTests
+      AgentTests.ResolveNameTests
      AgentTests.ServerChoice
      AgentTests.ShortLinkTests
      CLITests
@@ -530,9 +550,12 @@ test-suite simplexmq-test
      CoreTests.VersionRangeTests
      FileDescriptionTests
      RemoteControl
+      NamesResolverServer
+      RSLVTests
      ServerTests
      SMPAgentClient
      SMPClient
+      SMPNamesTests
      SMPProxyTests
      Util
      XFTPAgent
@@ -555,6 +578,7 @@ test-suite simplexmq-test
  if flag(server_postgres)
      other-modules:
          AgentTests.NotificationTests
+          CoreTests.XFTPStoreTests
          NtfClient
          NtfServerTests
  if flag(client_postgres) || flag(server_postgres)
@@ -612,6 +636,8 @@ test-suite simplexmq-test
    , unliftio
    , unliftio-core
    , unordered-containers
+    , wai
+    , warp
    , yaml
  default-language: Haskell2010
  if flag(server_postgres)
@@ -109,12 +109,6 @@ data XFTPClientConfig = XFTPClientConfig
    clientALPN :: Maybe [ALPN]
  }

-data XFTPChunkBody = XFTPChunkBody
-  { chunkSize :: Int,
-    chunkPart :: Int -> IO ByteString,
-    http2Body :: HTTP2Body
-  }
-
 data XFTPChunkSpec = XFTPChunkSpec
  { filePath :: FilePath,
    chunkOffset :: Int64,
@@ -147,7 +141,7 @@ getXFTPClient transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN,
  let HTTP2Client {sessionId, sessionALPN} = http2Client
      v = VersionXFTP 1
      thServerVRange = versionToRange v
-      thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = v, thServerVRange, thAuth = Nothing, implySessId = False, encryptBlock = Nothing, batch = True, serviceAuth = False}
+      thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = v, thServerVRange, thAuth = Nothing, implySessId = False, encryptBlock = Nothing, serviceAuth = False, serverInfo = Nothing}
  logDebug $ "Client negotiated handshake protocol: " <> tshow sessionALPN
  thParams@THandleParams {thVersion} <- case sessionALPN of
    Just alpn
@@ -14,6 +14,7 @@ module Simplex.FileTransfer.Client.Main
  ( SendOptions (..),
    CLIError (..),
    xftpClientCLI,
+    xftpClientDeprecationNotice,
    cliSendFile,
    cliSendFileOpts,
    encodeWebURI,
@@ -69,7 +70,6 @@ import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String (StrEncoding (..))
 import Simplex.Messaging.Parsers (parseAll)
 import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), ProtocolServer (..), SenderId, SndPrivateAuthKey, XFTPServer, XFTPServerWithAuth)
-import Simplex.Messaging.Server.CLI (getCliCommand')
 import Simplex.Messaging.Util (groupAllOn, ifM, tshow, whenM)
 import System.Exit (exitFailure)
 import System.FilePath (splitFileName, (</>))
@@ -81,6 +81,10 @@ import UnliftIO.Directory
 xftpClientVersion :: String
 xftpClientVersion = "1.0.1"

+xftpClientDeprecationNotice :: String
+xftpClientDeprecationNotice =
+  "WARNING: the standalone xftp CLI is experimental and deprecated."
+
 newtype CLIError = CLIError String
  deriving (Eq, Show, Exception)

@@ -223,7 +227,13 @@ logCfg = LogConfig {lc_file = Nothing, lc_stderr = True}

 xftpClientCLI :: IO ()
 xftpClientCLI =
-  getCliCommand' cliCommandP clientVersion >>= \case
+  customExecParser
+    (prefs showHelpOnEmpty)
+    ( info
+        (helper <*> versionOption <*> cliCommandP)
+        (header (clientVersion <> "\n" <> xftpClientDeprecationNotice) <> fullDesc)
+    )
+    >>= \case
    SendFile opts -> runLogE opts $ cliSendFile opts
    ReceiveFile opts -> runLogE opts $ cliReceiveFile opts
    DeleteFile opts -> runLogE opts $ cliDeleteFile opts
@@ -231,6 +241,7 @@ xftpClientCLI =
    RandomFile opts -> cliRandomFile opts
  where
    clientVersion = "SimpleX XFTP client v" <> xftpClientVersion
+    versionOption = infoOption clientVersion (long "version" <> short 'v' <> help "Show version")

 runLogE :: HasField "verbose" a Bool => a -> ExceptT CLIError IO () -> IO ()
 runLogE opts a
@@ -31,7 +31,6 @@ import qualified Data.ByteString.Char8 as B
 import Data.Int (Int64)
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.List.NonEmpty as L
-import qualified Data.Map.Strict as M
 import Data.Maybe (fromMaybe, isJust)
 import qualified Data.Text as T
 import qualified Data.Text.IO as T
@@ -88,7 +87,7 @@ import UnliftIO.Concurrent (threadDelay)
 import UnliftIO.Directory (canonicalizePath, doesFileExist, removeFile, renameFile)
 import qualified UnliftIO.Exception as E

-type M a = ReaderT XFTPEnv IO a
+type M s a = ReaderT (XFTPEnv s) IO a

 data XFTPTransportRequest = XFTPTransportRequest
  { thParams :: THandleParamsXFTP 'TServer,
@@ -112,19 +111,19 @@ corsPreflightHeaders =
    ("Access-Control-Max-Age", "86400")
  ]

-runXFTPServer :: XFTPServerConfig -> IO ()
+runXFTPServer :: FileStoreClass s => XFTPServerConfig s -> IO ()
 runXFTPServer cfg = do
  started <- newEmptyTMVarIO
  runXFTPServerBlocking started cfg

-runXFTPServerBlocking :: TMVar Bool -> XFTPServerConfig -> IO ()
+runXFTPServerBlocking :: FileStoreClass s => TMVar Bool -> XFTPServerConfig s -> IO ()
 runXFTPServerBlocking started cfg = newXFTPServerEnv cfg >>= runReaderT (xftpServer cfg started)

 data Handshake
  = HandshakeSent C.PrivateKeyX25519
  | HandshakeAccepted (THandleParams XFTPVersion 'TServer)

-xftpServer :: XFTPServerConfig -> TMVar Bool -> M ()
+xftpServer :: forall s. FileStoreClass s => XFTPServerConfig s -> TMVar Bool -> M s ()
 xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpiration, fileExpiration, xftpServerVRange} started = do
  mapM_ (expireServerFiles Nothing) fileExpiration
  restoreServerStats
@@ -137,7 +136,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
    )
    `finally` stopServer
  where
-    runServer :: M ()
+    runServer :: M s ()
    runServer = do
      srvCreds@(chain, pk) <- asks tlsServerCreds
      httpCreds_ <- asks httpServerCreds
@@ -158,7 +157,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
            reqBody <- getHTTP2Body r xftpBlockSize
            let v = VersionXFTP 1
                thServerVRange = versionToRange v
-                thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = v, thServerVRange, thAuth = Nothing, implySessId = False, encryptBlock = Nothing, batch = True, serviceAuth = False}
+                thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = v, thServerVRange, thAuth = Nothing, implySessId = False, encryptBlock = Nothing, serviceAuth = False, serverInfo = Nothing}
                req0 = XFTPTransportRequest {thParams = thParams0, request = r, reqBody, sendResponse, sniUsed, addCORS = addCORS'}
            flip runReaderT env $ case sessionALPN of
              Nothing -> processRequest req0
@@ -168,7 +167,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
                      Nothing -> pure ()
                      Just thParams -> processRequest req0 {thParams}
                | otherwise -> liftIO . sendResponse $ H.responseNoBody N.ok200 (corsHeaders addCORS')
-    xftpServerHandshakeV1 :: X.CertificateChain -> C.APrivateSignKey -> TMap SessionId Handshake -> XFTPTransportRequest -> M (Maybe (THandleParams XFTPVersion 'TServer))
+    xftpServerHandshakeV1 :: X.CertificateChain -> C.APrivateSignKey -> TMap SessionId Handshake -> XFTPTransportRequest -> M s (Maybe (THandleParams XFTPVersion 'TServer))
    xftpServerHandshakeV1 chain serverSignKey sessions XFTPTransportRequest {thParams = thParams0@THandleParams {sessionId}, request, reqBody = HTTP2Body {bodyHead}, sendResponse, sniUsed, addCORS} = do
      s <- atomically $ TM.lookup sessionId sessions
      r <- runExceptT $ case s of
@@ -227,39 +226,40 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
              liftIO . sendResponse $ H.responseNoBody N.ok200 (corsHeaders addCORS)
              pure Nothing
            Nothing -> throwE HANDSHAKE
-        sendError :: XFTPErrorType -> M (Maybe (THandleParams XFTPVersion 'TServer))
+        sendError :: XFTPErrorType -> M s (Maybe (THandleParams XFTPVersion 'TServer))
        sendError err = do
          runExceptT (encodeXftp err) >>= \case
            Right bs -> liftIO . sendResponse $ H.responseBuilder N.ok200 (corsHeaders addCORS) bs
            Left _ -> logError $ "Error encoding handshake error: " <> tshow err
          pure Nothing
-        encodeXftp :: Encoding a => a -> ExceptT XFTPErrorType (ReaderT XFTPEnv IO) Builder
+        encodeXftp :: Encoding a => a -> ExceptT XFTPErrorType (ReaderT (XFTPEnv s) IO) Builder
        encodeXftp a = byteString <$> liftHS (C.pad (smpEncode a) xftpBlockSize)
        liftHS = liftEitherWith (const HANDSHAKE)

-    stopServer :: M ()
+    stopServer :: M s ()
    stopServer = do
-      withFileLog closeStoreLog
+      st <- asks fileStore
+      liftIO $ closeFileStore st
      saveServerStats
      logNote "Server stopped"

-    expireFilesThread_ :: XFTPServerConfig -> [M ()]
+    expireFilesThread_ :: XFTPServerConfig s -> [M s ()]
    expireFilesThread_ XFTPServerConfig {fileExpiration = Just fileExp} = [expireFiles fileExp]
    expireFilesThread_ _ = []

-    expireFiles :: ExpirationConfig -> M ()
+    expireFiles :: ExpirationConfig -> M s ()
    expireFiles expCfg = do
      let interval = checkInterval expCfg * 1000000
      forever $ do
        liftIO $ threadDelay' interval
        expireServerFiles (Just 100000) expCfg

-    serverStatsThread_ :: XFTPServerConfig -> [M ()]
+    serverStatsThread_ :: XFTPServerConfig s -> [M s ()]
    serverStatsThread_ XFTPServerConfig {logStatsInterval = Just interval, logStatsStartTime, serverStatsLogFile} =
      [logServerStats logStatsStartTime interval serverStatsLogFile]
    serverStatsThread_ _ = []

-    logServerStats :: Int64 -> Int64 -> FilePath -> M ()
+    logServerStats :: Int64 -> Int64 -> FilePath -> M s ()
    logServerStats startAt logInterval statsFilePath = do
      initialDelay <- (startAt -) . fromIntegral . (`div` 1000000_000000) . diffTimeToPicoseconds . utctDayTime <$> liftIO getCurrentTime
      liftIO $ putStrLn $ "server stats log enabled: " <> statsFilePath
@@ -300,12 +300,12 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
              ]
        liftIO $ threadDelay' interval

-    prometheusMetricsThread_ :: XFTPServerConfig -> [M ()]
+    prometheusMetricsThread_ :: XFTPServerConfig s -> [M s ()]
    prometheusMetricsThread_ XFTPServerConfig {prometheusInterval = Just interval, prometheusMetricsFile} =
      [savePrometheusMetrics interval prometheusMetricsFile]
    prometheusMetricsThread_ _ = []

-    savePrometheusMetrics :: Int -> FilePath -> M ()
+    savePrometheusMetrics :: Int -> FilePath -> M s ()
    savePrometheusMetrics saveInterval metricsFile = do
      labelMyThread "savePrometheusMetrics"
      liftIO $ putStrLn $ "Prometheus metrics saved every " <> show saveInterval <> " seconds to " <> metricsFile
@@ -324,11 +324,11 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
      let fd = periodStatDataCounts $ _filesDownloaded d
      pure FileServerMetrics {statsData = d, filesDownloadedPeriods = fd, rtsOptions}

-    controlPortThread_ :: XFTPServerConfig -> [M ()]
+    controlPortThread_ :: XFTPServerConfig s -> [M s ()]
    controlPortThread_ XFTPServerConfig {controlPort = Just port} = [runCPServer port]
    controlPortThread_ _ = []

-    runCPServer :: ServiceName -> M ()
+    runCPServer :: ServiceName -> M s ()
    runCPServer port = do
      cpStarted <- newEmptyTMVarIO
      u <- askUnliftIO
@@ -336,7 +336,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
        labelMyThread "control port server"
        runLocalTCPServer cpStarted port $ runCPClient u
      where
-        runCPClient :: UnliftIO (ReaderT XFTPEnv IO) -> Socket -> IO ()
+        runCPClient :: UnliftIO (ReaderT (XFTPEnv s) IO) -> Socket -> IO ()
        runCPClient u sock = do
          labelMyThread "control port client"
          h <- socketToHandle sock ReadWriteMode
@@ -366,15 +366,15 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
                  XFTPServerConfig {controlPortUserAuth = user, controlPortAdminAuth = admin} = cfg
              CPStatsRTS -> E.tryAny getRTSStats >>= either (hPrint h) (hPrint h)
              CPDelete fileId -> withUserRole $ unliftIO u $ do
-                fs <- asks store
+                fs <- asks fileStore
                r <- runExceptT $ do
-                  (fr, _) <- ExceptT $ atomically $ getFile fs SFRecipient fileId
+                  (fr, _) <- ExceptT $ liftIO $ getFile fs SFRecipient fileId
                  ExceptT $ deleteServerFile_ fr
                liftIO . hPutStrLn h $ either (\e -> "error: " <> show e) (\() -> "ok") r
              CPBlock fileId info -> withUserRole $ unliftIO u $ do
-                fs <- asks store
+                fs <- asks fileStore
                r <- runExceptT $ do
-                  (fr, _) <- ExceptT $ atomically $ getFile fs SFRecipient fileId
+                  (fr, _) <- ExceptT $ liftIO $ getFile fs SFRecipient fileId
                  ExceptT $ blockServerFile fr info
                liftIO . hPutStrLn h $ either (\e -> "error: " <> show e) (\() -> "ok") r
              CPHelp -> hPutStrLn h "commands: stats-rts, delete, help, quit"
@@ -395,7 +395,7 @@ data ServerFile = ServerFile
    sbState :: LC.SbState
  }

-processRequest :: XFTPTransportRequest -> M ()
+processRequest :: FileStoreClass s => XFTPTransportRequest -> M s ()
 processRequest XFTPTransportRequest {thParams, reqBody = body@HTTP2Body {bodyHead}, sendResponse, addCORS}
  | B.length bodyHead /= xftpBlockSize = sendXFTPResponse ("", NoEntity, FRErr BLOCK) Nothing
  | otherwise =
@@ -430,7 +430,7 @@ processRequest XFTPTransportRequest {thParams, reqBody = body@HTTP2Body {bodyHea
          done

 #ifdef slow_servers
-randomDelay :: M ()
+randomDelay :: M s ()
 randomDelay = do
  d <- asks $ responseDelay . config
  when (d > 0) $ do
@@ -440,20 +440,20 @@ randomDelay = do

 data VerificationResult = VRVerified XFTPRequest | VRFailed XFTPErrorType

-verifyXFTPTransmission :: Maybe (THandleAuth 'TServer) -> SignedTransmission FileCmd -> M VerificationResult
+verifyXFTPTransmission :: forall s. FileStoreClass s => Maybe (THandleAuth 'TServer) -> SignedTransmission FileCmd -> M s VerificationResult
 verifyXFTPTransmission thAuth (tAuth, authorized, (corrId, fId, cmd)) =
  case cmd of
    FileCmd SFSender (FNEW file rcps auth') -> pure $ XFTPReqNew file rcps auth' `verifyWith` sndKey file
    FileCmd SFRecipient PING -> pure $ VRVerified XFTPReqPing
    FileCmd party _ -> verifyCmd party
  where
-    verifyCmd :: SFileParty p -> M VerificationResult
+    verifyCmd :: SFileParty p -> M s VerificationResult
    verifyCmd party = do
-      st <- asks store
-      atomically $ verify =<< getFile st party fId
+      st <- asks fileStore
+      liftIO $ verify =<< getFile st party fId
      where
        verify = \case
-          Right (fr, k) -> result <$> readTVar (fileStatus fr)
+          Right (fr, k) -> result <$> readTVarIO (fileStatus fr)
            where
              result = \case
                EntityActive -> XFTPReqCmd fId fr cmd `verifyWith` k
@@ -464,7 +464,7 @@ verifyXFTPTransmission thAuth (tAuth, authorized, (corrId, fId, cmd)) =
    -- TODO verify with DH authorization
    req `verifyWith` k = if verifyCmdAuthorization thAuth tAuth authorized corrId k then VRVerified req else VRFailed AUTH

-processXFTPRequest :: HTTP2Body -> XFTPRequest -> M (FileResponse, Maybe ServerFile)
+processXFTPRequest :: forall s. FileStoreClass s => HTTP2Body -> XFTPRequest -> M s (FileResponse, Maybe ServerFile)
 processXFTPRequest HTTP2Body {bodyPart} = \case
  XFTPReqNew file rks auth -> noFile =<< ifM allowNew (createFile file rks) (pure $ FRErr AUTH)
    where
@@ -483,9 +483,9 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
  XFTPReqPing -> noFile FRPong
  where
    noFile resp = pure (resp, Nothing)
-    createFile :: FileInfo -> NonEmpty RcvPublicAuthKey -> M FileResponse
+    createFile :: FileInfo -> NonEmpty RcvPublicAuthKey -> M s FileResponse
    createFile file rks = do
-      st <- asks store
+      st <- asks fileStore
      r <- runExceptT $ do
        sizes <- asks $ allowedChunkSizes . config
        unless (size file `elem` sizes) $ throwE SIZE
@@ -502,27 +502,27 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
        let rIds = L.map (\(FileRecipient rId _) -> rId) rcps
        pure $ FRSndIds sId rIds
      pure $ either FRErr id r
-    addFileRetry :: FileStore -> FileInfo -> Int -> RoundedFileTime -> M (Either XFTPErrorType XFTPFileId)
+    addFileRetry :: s -> FileInfo -> Int -> RoundedFileTime -> M s (Either XFTPErrorType XFTPFileId)
    addFileRetry st file n ts =
      retryAdd n $ \sId -> runExceptT $ do
        ExceptT $ addFile st sId file ts EntityActive
        pure sId
-    addRecipientRetry :: FileStore -> Int -> XFTPFileId -> RcvPublicAuthKey -> M (Either XFTPErrorType FileRecipient)
+    addRecipientRetry :: s -> Int -> XFTPFileId -> RcvPublicAuthKey -> M s (Either XFTPErrorType FileRecipient)
    addRecipientRetry st n sId rpk =
      retryAdd n $ \rId -> runExceptT $ do
        let rcp = FileRecipient rId rpk
        ExceptT $ addRecipient st sId rcp
        pure rcp
-    retryAdd :: Int -> (XFTPFileId -> STM (Either XFTPErrorType a)) -> M (Either XFTPErrorType a)
+    retryAdd :: Int -> (XFTPFileId -> IO (Either XFTPErrorType a)) -> M s (Either XFTPErrorType a)
    retryAdd 0 _ = pure $ Left INTERNAL
    retryAdd n add = do
      fId <- getFileId
-      atomically (add fId) >>= \case
+      liftIO (add fId) >>= \case
        Left DUPLICATE_ -> retryAdd (n - 1) add
        r -> pure r
-    addRecipients :: XFTPFileId -> NonEmpty RcvPublicAuthKey -> M FileResponse
+    addRecipients :: XFTPFileId -> NonEmpty RcvPublicAuthKey -> M s FileResponse
    addRecipients sId rks = do
-      st <- asks store
+      st <- asks fileStore
      r <- runExceptT $ do
        rcps <- mapM (ExceptT . addRecipientRetry st 3 sId) rks
        lift $ withFileLog $ \sl -> logAddRecipients sl sId rcps
@@ -531,7 +531,7 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
        let rIds = L.map (\(FileRecipient rId _) -> rId) rcps
        pure $ FRRcvIds rIds
      pure $ either FRErr id r
-    receiveServerFile :: FileRec -> M FileResponse
+    receiveServerFile :: FileRec -> M s FileResponse
    receiveServerFile FileRec {senderId, fileInfo = FileInfo {size, digest}, filePath} = case bodyPart of
      Nothing -> pure $ FRErr SIZE
      -- TODO validate body size from request before downloading, once it's populated
@@ -549,7 +549,7 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
                  | bs == 0 || bs > s -> pure $ FRErr SIZE
                  | otherwise -> drain (s - bs)
          reserve = do
-            us <- asks $ usedStorage . store
+            us <- asks usedStorage
            quota <- asks $ fromMaybe maxBound . fileSizeQuota . config
            atomically . stateTVar us $
              \used -> let used' = used + fromIntegral size in if used' <= quota then (True, used') else (False, used)
@@ -559,21 +559,28 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
            receiveChunk (XFTPRcvChunkSpec fPath size digest) >>= \case
              Right () -> do
                stats <- asks serverStats
-                withFileLog $ \sl -> logPutFile sl senderId fPath
-                atomically $ writeTVar filePath (Just fPath)
-                incFileStat filesUploaded
-                incFileStat filesCount
-                liftIO $ atomicModifyIORef'_ (filesSize stats) (+ fromIntegral size)
-                pure FROk
+                st <- asks fileStore
+                liftIO (setFilePath st senderId fPath) >>= \case
+                  Right () -> do
+                    withFileLog $ \sl -> logPutFile sl senderId fPath
+                    incFileStat filesUploaded
+                    incFileStat filesCount
+                    liftIO $ atomicModifyIORef'_ (filesSize stats) (+ fromIntegral size)
+                    pure FROk
+                  Left _e -> do
+                    us <- asks usedStorage
+                    atomically $ modifyTVar' us $ subtract (fromIntegral size)
+                    liftIO $ whenM (doesFileExist fPath) (removeFile fPath) `catch` logFileError
+                    pure $ FRErr AUTH
              Left e -> do
-                us <- asks $ usedStorage . store
+                us <- asks usedStorage
                atomically $ modifyTVar' us $ subtract (fromIntegral size)
                liftIO $ whenM (doesFileExist fPath) (removeFile fPath) `catch` logFileError
                pure $ FRErr e
          receiveChunk spec = do
            t <- asks $ fileTimeout . config
            liftIO $ fromMaybe (Left TIMEOUT) <$> timeout t (runExceptT $ receiveFile getBody spec)
-    sendServerFile :: FileRec -> RcvPublicDhKey -> M (FileResponse, Maybe ServerFile)
+    sendServerFile :: FileRec -> RcvPublicDhKey -> M s (FileResponse, Maybe ServerFile)
    sendServerFile FileRec {senderId, filePath, fileInfo = FileInfo {size}} rDhKey = do
      readTVarIO filePath >>= \case
        Just path -> ifM (doesFileExist path) sendFile (pure (FRErr AUTH, Nothing))
@@ -592,38 +599,41 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
                _ -> pure (FRErr INTERNAL, Nothing)
        _ -> pure (FRErr NO_FILE, Nothing)

-    deleteServerFile :: FileRec -> M FileResponse
+    deleteServerFile :: FileRec -> M s FileResponse
    deleteServerFile fr = either FRErr (\() -> FROk) <$> deleteServerFile_ fr

    logFileError :: SomeException -> IO ()
    logFileError e = logError $ "Error deleting file: " <> tshow e

-    ackFileReception :: RecipientId -> FileRec -> M FileResponse
+    ackFileReception :: RecipientId -> FileRec -> M s FileResponse
    ackFileReception rId fr = do
      withFileLog (`logAckFile` rId)
-      st <- asks store
-      atomically $ deleteRecipient st rId fr
+      st <- asks fileStore
+      liftIO $ deleteRecipient st rId fr
      incFileStat fileDownloadAcks
      pure FROk

-deleteServerFile_ :: FileRec -> M (Either XFTPErrorType ())
+deleteServerFile_ :: FileStoreClass s => FileRec -> M s (Either XFTPErrorType ())
 deleteServerFile_ fr@FileRec {senderId} = do
  withFileLog (`logDeleteFile` senderId)
  deleteOrBlockServerFile_ fr filesDeleted (`deleteFile` senderId)

 -- this also deletes the file from storage, but doesn't include it in delete statistics
-blockServerFile :: FileRec -> BlockingInfo -> M (Either XFTPErrorType ())
+blockServerFile :: FileStoreClass s => FileRec -> BlockingInfo -> M s (Either XFTPErrorType ())
 blockServerFile fr@FileRec {senderId} info = do
  withFileLog $ \sl -> logBlockFile sl senderId info
  deleteOrBlockServerFile_ fr filesBlocked $ \st -> blockFile st senderId info True

-deleteOrBlockServerFile_ :: FileRec -> (FileServerStats -> IORef Int) -> (FileStore -> STM (Either XFTPErrorType ())) -> M (Either XFTPErrorType ())
+deleteOrBlockServerFile_ :: FileStoreClass s => FileRec -> (FileServerStats -> IORef Int) -> (s -> IO (Either XFTPErrorType ())) -> M s (Either XFTPErrorType ())
 deleteOrBlockServerFile_ FileRec {filePath, fileInfo} stat storeAction = runExceptT $ do
  path <- readTVarIO filePath
  stats <- asks serverStats
  ExceptT $ first (\(_ :: SomeException) -> FILE_IO) <$> try (forM_ path $ \p -> whenM (doesFileExist p) (removeFile p >> deletedStats stats))
-  st <- asks store
-  void $ atomically $ storeAction st
+  st <- asks fileStore
+  ExceptT $ liftIO $ storeAction st
+  forM_ path $ \_ -> do
+    us <- asks usedStorage
+    atomically $ modifyTVar' us $ subtract (fromIntegral $ size fileInfo)
  lift $ incFileStat stat
  where
    deletedStats stats = do
@@ -633,47 +643,50 @@ deleteOrBlockServerFile_ FileRec {filePath, fileInfo} stat storeAction = runExce
 getFileTime :: IO RoundedFileTime
 getFileTime = getRoundedSystemTime

-expireServerFiles :: Maybe Int -> ExpirationConfig -> M ()
+expireServerFiles :: FileStoreClass s => Maybe Int -> ExpirationConfig -> M s ()
 expireServerFiles itemDelay expCfg = do
-  st <- asks store
-  usedStart <- readTVarIO $ usedStorage st
+  st <- asks fileStore
+  us <- asks usedStorage
+  usedStart <- readTVarIO us
  old <- liftIO $ expireBeforeEpoch expCfg
-  files' <- readTVarIO (files st)
-  logNote $ "Expiration check: " <> tshow (M.size files') <> " files"
-  forM_ (M.keys files') $ \sId -> do
-    mapM_ threadDelay itemDelay
-    atomically (expiredFilePath st sId old)
-      >>= mapM_ (maybeRemove $ delete st sId)
-  usedEnd <- readTVarIO $ usedStorage st
+  filesCount <- liftIO $ getFileCount st
+  logNote $ "Expiration check: " <> tshow filesCount <> " files"
+  expireLoop st us old
+  usedEnd <- readTVarIO us
  logNote $ "Used " <> mbs usedStart <> " -> " <> mbs usedEnd <> ", " <> mbs (usedStart - usedEnd) <> " reclaimed."
  where
    mbs bs = tshow (bs `div` 1048576) <> "mb"
-    maybeRemove del = maybe del (remove del)
-    remove del filePath =
-      ifM
-        (doesFileExist filePath)
-        ((removeFile filePath >> del) `catch` \(e :: SomeException) -> logError $ "failed to remove expired file " <> tshow filePath <> ": " <> tshow e)
-        del
-    delete st sId = do
-      withFileLog (`logDeleteFile` sId)
-      void . atomically $ deleteFile st sId -- will not update usedStorage if sId isn't in store
-      incFileStat filesExpired
+    expireLoop st us old = do
+      expired <- liftIO $ expiredFiles st old 10000
+      forM_ expired $ \(sId, filePath_, fileSize) -> do
+        mapM_ threadDelay itemDelay
+        forM_ filePath_ $ \fp ->
+          whenM (doesFileExist fp) $
+            removeFile fp `catch` \(e :: SomeException) -> logError $ "failed to remove expired file " <> tshow fp <> ": " <> tshow e
+        forM_ filePath_ $ \_ ->
+          atomically $ modifyTVar' us $ subtract (fromIntegral fileSize)
+        incFileStat filesExpired
+      let sIds = map (\(sId, _, _) -> sId) expired
+      unless (null sIds) $ do
+        withFileLog $ \sl -> mapM_ (logDeleteFile sl) sIds
+        liftIO $ deleteFiles st sIds
+        expireLoop st us old

-randomId :: Int -> M ByteString
+randomId :: Int -> M s ByteString
 randomId n = atomically . C.randomBytes n =<< asks random

-getFileId :: M XFTPFileId
+getFileId :: M s XFTPFileId
 getFileId = fmap EntityId . randomId =<< asks (fileIdSize . config)

-withFileLog :: (StoreLog 'WriteMode -> IO a) -> M ()
+withFileLog :: (StoreLog 'WriteMode -> IO a) -> M s ()
 withFileLog action = liftIO . mapM_ action =<< asks storeLog

-incFileStat :: (FileServerStats -> IORef Int) -> M ()
+incFileStat :: (FileServerStats -> IORef Int) -> M s ()
 incFileStat statSel = do
  stats <- asks serverStats
  liftIO $ atomicModifyIORef'_ (statSel stats) (+ 1)

-saveServerStats :: M ()
+saveServerStats :: M s ()
 saveServerStats =
  asks (serverStatsBackupFile . config)
    >>= mapM_ (\f -> asks serverStats >>= liftIO . getFileServerStatsData >>= liftIO . saveStats f)
@@ -683,7 +696,7 @@ saveServerStats =
      B.writeFile f $ strEncode stats
      logNote "server stats saved"

-restoreServerStats :: M ()
+restoreServerStats :: FileStoreClass s => M s ()
 restoreServerStats = asks (serverStatsBackupFile . config) >>= mapM_ restoreStats
  where
    restoreStats f = whenM (doesFileExist f) $ do
@@ -691,9 +704,9 @@ restoreServerStats = asks (serverStatsBackupFile . config) >>= mapM_ restoreStat
      liftIO (strDecode <$> B.readFile f) >>= \case
        Right d@FileServerStatsData {_filesCount = statsFilesCount, _filesSize = statsFilesSize} -> do
          s <- asks serverStats
-          FileStore {files, usedStorage} <- asks store
-          _filesCount <- M.size <$> readTVarIO files
-          _filesSize <- readTVarIO usedStorage
+          st <- asks fileStore
+          _filesCount <- liftIO $ getFileCount st
+          _filesSize <- readTVarIO =<< asks usedStorage
          liftIO $ setFileServerStats s d {_filesCount, _filesSize}
          renameFile f $ f <> ".bak"
          logNote "server stats restored"
@@ -1,21 +1,35 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE KindSignatures #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE StrictData #-}
+{-# LANGUAGE TypeFamilies #-}

 module Simplex.FileTransfer.Server.Env
  ( XFTPServerConfig (..),
+    XFTPStoreConfig (..),
    XFTPEnv (..),
    XFTPRequest (..),
+    XFTPStoreType,
+    FileStore (..),
+    AFStoreType (..),
+    fileStore,
+    fromFileStore,
    defaultInactiveClientExpiration,
    defFileExpirationHours,
    defaultFileExpiration,
    newXFTPServerEnv,
-    countUsedStorage,
+    readFileStoreType,
+    runWithStoreConfig,
+    checkFileStoreMode,
+    importToDatabase,
+    exportFromDatabase,
  ) where

 import Control.Logger.Simple
@@ -23,7 +37,6 @@ import Control.Monad
 import Crypto.Random
 import Data.Int (Int64)
 import Data.List.NonEmpty (NonEmpty)
-import qualified Data.Map.Strict as M
 import Data.Time.Clock (getCurrentTime)
 import Data.Word (Word32)
 import Data.X509.Validation (Fingerprint (..))
@@ -31,7 +44,21 @@ import Network.Socket
 import qualified Network.TLS as T
 import Simplex.FileTransfer.Protocol (FileCmd, FileInfo (..), XFTPFileId)
 import Simplex.FileTransfer.Server.Stats
+import Data.Either (fromRight)
+import Data.Ini (Ini, lookupValue)
+import qualified Data.Text as T
 import Simplex.FileTransfer.Server.Store
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation)
+import Data.Functor (($>))
+import Simplex.Messaging.Server.CLI (settingIsOn)
+import System.Exit (exitFailure)
+#if defined(dbServerPostgres)
+import Data.Maybe (isNothing)
+import Simplex.FileTransfer.Server.Store.Postgres (PostgresFileStore, importFileStore, exportFileStore)
+import Simplex.FileTransfer.Server.Store.Postgres.Config (PostgresFileStoreCfg (..), defaultXFTPDBOpts)
+import Simplex.Messaging.Server.CLI (iniDBOptions)
+import System.Directory (doesFileExist)
+#endif
 import Simplex.FileTransfer.Server.StoreLog
 import Simplex.FileTransfer.Transport (VersionRangeXFTP)
 import qualified Simplex.Messaging.Crypto as C
@@ -42,10 +69,11 @@ import Simplex.Messaging.Util (tshow)
 import System.IO (IOMode (..))
 import UnliftIO.STM

-data XFTPServerConfig = XFTPServerConfig
+data XFTPServerConfig s = XFTPServerConfig
  { xftpPort :: ServiceName,
    controlPort :: Maybe ServiceName,
    fileIdSize :: Int,
+    serverStoreCfg :: XFTPStoreConfig s,
    storeLogFile :: Maybe FilePath,
    filesPath :: FilePath,
    -- | server storage quota
@@ -88,9 +116,10 @@ defaultInactiveClientExpiration =
      checkInterval = 3600 -- seconds, 1 hours
    }

-data XFTPEnv = XFTPEnv
-  { config :: XFTPServerConfig,
-    store :: FileStore,
+data XFTPEnv s = XFTPEnv
+  { config :: XFTPServerConfig s,
+    store :: FileStore s,
+    usedStorage :: TVar Int64,
    storeLog :: Maybe (StoreLog 'WriteMode),
    random :: TVar ChaChaDRG,
    serverIdentity :: C.KeyHash,
@@ -99,6 +128,38 @@ data XFTPEnv = XFTPEnv
    serverStats :: FileServerStats
  }

+fileStore :: XFTPEnv s -> s
+fileStore = fromFileStore . store
+{-# INLINE fileStore #-}
+
+data XFTPStoreConfig s where
+  XSCMemory :: Maybe FilePath -> XFTPStoreConfig STMFileStore
+#if defined(dbServerPostgres)
+  XSCDatabase :: PostgresFileStoreCfg -> XFTPStoreConfig PostgresFileStore
+#endif
+
+type family XFTPStoreType (fs :: FSType) where
+  XFTPStoreType 'FSMemory = STMFileStore
+#if defined(dbServerPostgres)
+  XFTPStoreType 'FSPostgres = PostgresFileStore
+#endif
+
+data FileStore s where
+  StoreMemory :: STMFileStore -> FileStore STMFileStore
+#if defined(dbServerPostgres)
+  StoreDatabase :: PostgresFileStore -> FileStore PostgresFileStore
+#endif
+
+data AFStoreType = forall fs. AFSType (SFSType fs)
+
+fromFileStore :: FileStore s -> s
+fromFileStore = \case
+  StoreMemory s -> s
+#if defined(dbServerPostgres)
+  StoreDatabase s -> s
+#endif
+{-# INLINE fromFileStore #-}
+
 defFileExpirationHours :: Int64
 defFileExpirationHours = 48

@@ -109,13 +170,22 @@ defaultFileExpiration =
      checkInterval = 2 * 3600 -- seconds, 2 hours
    }

-newXFTPServerEnv :: XFTPServerConfig -> IO XFTPEnv
-newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, xftpCredentials, httpCredentials} = do
+newXFTPServerEnv :: FileStoreClass s => XFTPServerConfig s -> IO (XFTPEnv s)
+newXFTPServerEnv config@XFTPServerConfig {serverStoreCfg, fileSizeQuota, xftpCredentials, httpCredentials} = do
  random <- C.newRandom
-  store <- newFileStore
-  storeLog <- mapM (`readWriteFileStore` store) storeLogFile
-  used <- countUsedStorage <$> readTVarIO (files store)
-  atomically $ writeTVar (usedStorage store) used
+  (store, storeLog) <- case serverStoreCfg of
+    XSCMemory storeLogPath -> do
+      st <- newFileStore ()
+      sl <- mapM (`readWriteFileStore` st) storeLogPath
+      atomically $ writeTVar (stmStoreLog st) sl
+      pure (StoreMemory st, sl)
+#if defined(dbServerPostgres)
+    XSCDatabase dbCfg -> do
+      st <- newFileStore dbCfg
+      pure (StoreDatabase st, Nothing)
+#endif
+  used <- getUsedStorage (fromFileStore store)
+  usedStorage <- newTVarIO used
  forM_ fileSizeQuota $ \quota -> do
    logNote $ "Total / available storage: " <> tshow quota <> " / " <> tshow (quota - used)
    when (quota < used) $ logWarn "WARNING: storage quota is less than used storage, no files can be uploaded!"
@@ -123,12 +193,76 @@ newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, xftpCrede
  httpServerCreds <- mapM loadServerCredential httpCredentials
  Fingerprint fp <- loadFingerprint xftpCredentials
  serverStats <- newFileServerStats =<< getCurrentTime
-  pure XFTPEnv {config, store, storeLog, random, tlsServerCreds, httpServerCreds, serverIdentity = C.KeyHash fp, serverStats}
-
-countUsedStorage :: M.Map k FileRec -> Int64
-countUsedStorage = M.foldl' (\acc FileRec {fileInfo = FileInfo {size}} -> acc + fromIntegral size) 0
+  pure XFTPEnv {config, store, usedStorage, storeLog, random, tlsServerCreds, httpServerCreds, serverIdentity = C.KeyHash fp, serverStats}

 data XFTPRequest
  = XFTPReqNew FileInfo (NonEmpty RcvPublicAuthKey) (Maybe BasicAuth)
  | XFTPReqCmd XFTPFileId FileRec FileCmd
  | XFTPReqPing
+
+readFileStoreType :: Ini -> Either String AFStoreType
+readFileStoreType ini = case fromRight "memory" $ T.unpack <$> lookupValue "STORE_LOG" "store_files" ini of
+  "memory" -> Right $ AFSType SFSMemory
+  "database" -> Right $ AFSType SFSPostgres
+  other -> Left $ "Invalid store_files value: " <> other
+
+-- | Dispatch store config from AFStoreType singleton and run the callback.
+-- CPP guards for Postgres are handled here so Main.hs stays CPP-free.
+runWithStoreConfig ::
+  AFStoreType ->
+  Ini ->
+  FilePath ->
+  MigrationConfirmation ->
+  (forall s. FileStoreClass s => XFTPStoreConfig s -> IO ()) ->
+  IO ()
+runWithStoreConfig (AFSType SFSMemory) ini storeLogFilePath _confirmMigrations run =
+  run $ XSCMemory (enableStoreLog' $> storeLogFilePath)
+  where
+    enableStoreLog' = settingIsOn "STORE_LOG" "enable" ini
+runWithStoreConfig (AFSType SFSPostgres) ini storeLogFilePath confirmMigrations run =
+#if defined(dbServerPostgres)
+  run $ XSCDatabase dbCfg
+  where
+    enableDbStoreLog' = settingIsOn "STORE_LOG" "db_store_log" ini
+    dbStoreLogPath = enableDbStoreLog' $> storeLogFilePath
+    dbCfg = PostgresFileStoreCfg {dbOpts = iniDBOptions ini defaultXFTPDBOpts, dbStoreLogPath, confirmMigrations}
+#else
+  error "server binary is compiled without support for PostgreSQL database"
+#endif
+
+-- | Validate startup config when store_files=database.
+checkFileStoreMode :: Ini -> AFStoreType -> FilePath -> IO ()
+checkFileStoreMode ini (AFSType SFSPostgres) storeLogFilePath = do
+#if defined(dbServerPostgres)
+  storeLogExists <- doesFileExist storeLogFilePath
+  let dbStoreLogOn = settingIsOn "STORE_LOG" "db_store_log" ini
+  when (storeLogExists && isNothing dbStoreLogOn) $ do
+    putStrLn $ "Error: store log file " <> storeLogFilePath <> " exists but store_files is `database`."
+    putStrLn "Use `file-server database import` to migrate, or set `db_store_log: on`."
+    exitFailure
+#else
+  putStrLn "Error: server binary is compiled without support for PostgreSQL database."
+  putStrLn "Please re-compile with `cabal build -fserver_postgres`."
+  exitFailure
+#endif
+checkFileStoreMode _ (AFSType SFSMemory) _ = pure ()
+
+-- | Import StoreLog to PostgreSQL database.
+importToDatabase :: FilePath -> Ini -> MigrationConfirmation -> IO ()
+#if defined(dbServerPostgres)
+importToDatabase storeLogFilePath ini _confirmMigrations = do
+  let dbCfg = PostgresFileStoreCfg {dbOpts = iniDBOptions ini defaultXFTPDBOpts, dbStoreLogPath = Nothing, confirmMigrations = _confirmMigrations}
+  importFileStore storeLogFilePath dbCfg
+#else
+importToDatabase _ _ _ = error "Error: server binary is compiled without support for PostgreSQL database.\nPlease re-compile with `cabal build -fserver_postgres`."
+#endif
+
+-- | Export PostgreSQL database to StoreLog.
+exportFromDatabase :: FilePath -> Ini -> MigrationConfirmation -> IO ()
+#if defined(dbServerPostgres)
+exportFromDatabase storeLogFilePath ini _confirmMigrations = do
+  let dbCfg = PostgresFileStoreCfg {dbOpts = iniDBOptions ini defaultXFTPDBOpts, dbStoreLogPath = Nothing, confirmMigrations = _confirmMigrations}
+  exportFileStore storeLogFilePath dbCfg
+#else
+exportFromDatabase _ _ _ = error "Error: server binary is compiled without support for PostgreSQL database.\nPlease re-compile with `cabal build -fserver_postgres`."
+#endif
@@ -5,6 +5,7 @@
 {-# LANGUAGE OverloadedLists #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeApplications #-}

 module Simplex.FileTransfer.Server.Main
@@ -12,7 +13,7 @@ module Simplex.FileTransfer.Server.Main
    xftpServerCLI_,
  ) where

-import Control.Monad (when)
+import Control.Monad (unless, when)
 import Data.Either (fromRight)
 import Data.Functor (($>))
 import Data.Ini (lookupValue, readIniFile)
@@ -28,11 +29,12 @@ import Options.Applicative
 import Simplex.FileTransfer.Chunks
 import Simplex.FileTransfer.Description (FileSize (..))
 import Simplex.FileTransfer.Server (runXFTPServer)
-import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defFileExpirationHours, defaultFileExpiration, defaultInactiveClientExpiration)
+import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), XFTPStoreConfig, AFStoreType (..), defFileExpirationHours, defaultFileExpiration, defaultInactiveClientExpiration, readFileStoreType, runWithStoreConfig, checkFileStoreMode, importToDatabase, exportFromDatabase)
 import Simplex.FileTransfer.Transport (alpnSupportedXFTPhandshakes, supportedFileServerVRange)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), pattern XFTPServer)
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation (..))
 import Simplex.Messaging.Server.CLI
 import Simplex.Messaging.Server.Expiration
 import Simplex.Messaging.Server.Information (ServerPublicInfo (..))
@@ -51,7 +53,7 @@ xftpServerCLI :: FilePath -> FilePath -> IO ()
 xftpServerCLI = xftpServerCLI_ (\_ _ _ _ -> pure ()) (\_ -> pure ())

 xftpServerCLI_ ::
-  (XFTPServerConfig -> Maybe ServerPublicInfo -> Maybe TransportHost -> FilePath -> IO ()) ->
+  (forall s. XFTPServerConfig s -> Maybe ServerPublicInfo -> Maybe TransportHost -> FilePath -> IO ()) ->
  (EmbeddedWebParams -> IO ()) ->
  FilePath ->
  FilePath ->
@@ -66,9 +68,13 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
      doesFileExist iniFile >>= \case
        True -> genOnline cfgPath certOpts
        _ -> exitError $ "Error: server is not initialized (" <> iniFile <> " does not exist).\nRun `" <> executableName <> " init`."
-    Start ->
+    Start opts ->
      doesFileExist iniFile >>= \case
-        True -> readIniFile iniFile >>= either exitError runServer
+        True -> readIniFile iniFile >>= either exitError (runServer opts)
+        _ -> exitError $ "Error: server is not initialized (" <> iniFile <> " does not exist).\nRun `" <> executableName <> " init`."
+    Database cmd ->
+      doesFileExist iniFile >>= \case
+        True -> readIniFile iniFile >>= either exitError (runDatabaseCmd cmd)
        _ -> exitError $ "Error: server is not initialized (" <> iniFile <> " does not exist).\nRun `" <> executableName <> " init`."
    Delete -> do
      confirmOrExit
@@ -84,6 +90,21 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
    executableName = "file-server"
    storeLogFilePath = combine logPath "file-server-store.log"
    defaultStaticPath = combine logPath "www"
+    runDatabaseCmd cmd ini = case cmd of
+      SCImport -> do
+        storeLogExists <- doesFileExist storeLogFilePath
+        unless storeLogExists $ exitError $ "Error: store log file " <> storeLogFilePath <> " does not exist."
+        confirmOrExit
+          ("Import store log " <> storeLogFilePath <> " to PostgreSQL database?")
+          "Import cancelled."
+        importToDatabase storeLogFilePath ini MCYesUp
+      SCExport -> do
+        storeLogExists <- doesFileExist storeLogFilePath
+        when storeLogExists $ exitError $ "Error: store log file " <> storeLogFilePath <> " already exists."
+        confirmOrExit
+          ("Export PostgreSQL database to store log " <> storeLogFilePath <> "?")
+          "Export cancelled."
+        exportFromDatabase storeLogFilePath ini MCConsole
    initializeServer InitOptions {enableStoreLog, signAlgorithm, ip, fqdn, filesPath, fileSizeQuota, webStaticPath = webStaticPath_} = do
      clearDirIfExists cfgPath
      clearDirIfExists logPath
@@ -104,20 +125,20 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
          \# available to the end users of the server.\n\
          \# LICENSE: https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE\n\
          \# Include correct source code URI in case the server source code is modified in any way.\n\
-          \# source_code: https://github.com/simplex-chat/simplexmq\n\
+          \# source_code = https://github.com/simplex-chat/simplexmq\n\
          \\n\
          \# Declaring all below information is optional, any of these fields can be omitted.\n\
-          \# server_country: ISO-3166 2-letter code\n\
-          \# operator: entity (organization or person name)\n\
-          \# operator_country: ISO-3166 2-letter code\n\
-          \# website:\n\
-          \# admin_simplex: SimpleX address\n\
-          \# admin_email:\n\
-          \# complaints_simplex: SimpleX address\n\
-          \# complaints_email:\n\
-          \# hosting: entity (organization or person name)\n\
-          \# hosting_country: ISO-3166 2-letter code\n\
-          \# hosting_type: virtual\n\
+          \# server_country = ISO-3166 2-letter code\n\
+          \# operator = entity (organization or person name)\n\
+          \# operator_country = ISO-3166 2-letter code\n\
+          \# website =\n\
+          \# admin_simplex = SimpleX address\n\
+          \# admin_email =\n\
+          \# complaints_simplex = SimpleX address\n\
+          \# complaints_email =\n\
+          \# hosting = entity (organization or person name)\n\
+          \# hosting_country = ISO-3166 2-letter code\n\
+          \# hosting_type = virtual\n\
          \\n\
          \[STORE_LOG]\n\
          \# The server uses STM memory for persistence,\n\
@@ -125,55 +146,63 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
          \# This option enables saving memory to append only log,\n\
          \# and restoring it when the server is started.\n\
          \# Log is compacted on start (deleted objects are removed).\n"
-            <> ("enable: " <> onOff enableStoreLog <> "\n\n")
+            <> ("enable = " <> onOff enableStoreLog <> "\n\n")
+            <> "# File storage mode: `memory` or `database` (PostgreSQL).\n\
+               \store_files = memory\n\n\
+               \# Database connection settings for PostgreSQL database (`store_files = database`).\n\
+               \# db_connection = postgresql://xftp@/xftp_server_store\n\
+               \# db_schema = xftp_server\n\
+               \# db_pool_size = 10\n\n\
+               \# Write database changes to store log file\n\
+               \# db_store_log = off\n\n"
            <> "# Expire files after the specified number of hours.\n"
-            <> ("expire_files_hours: " <> tshow defFileExpirationHours <> "\n\n")
-            <> "log_stats: off\n\
+            <> ("expire_files_hours = " <> tshow defFileExpirationHours <> "\n\n")
+            <> "log_stats = off\n\
               \\n\
               \# Log interval for real-time Prometheus metrics\n\
-               \# prometheus_interval: 60\n\
+               \# prometheus_interval = 60\n\
               \\n\
               \[AUTH]\n\
               \# Set new_files option to off to completely prohibit uploading new files.\n\
               \# This can be useful when you want to decommission the server, but still allow downloading the existing files.\n\
-               \new_files: on\n\
+               \new_files = on\n\
               \\n\
               \# Use create_password option to enable basic auth to upload new files.\n\
               \# The password should be used as part of server address in client configuration:\n\
               \# xftp://fingerprint:password@host1,host2\n\
               \# The password will not be shared with file recipients, you must share it only\n\
               \# with the users who you want to allow uploading files to your server.\n\
-               \# create_password: password to upload files (any printable ASCII characters without whitespace, '@', ':' and '/')\n\
+               \# create_password = password to upload files (any printable ASCII characters without whitespace, '@', ':' and '/')\n\
               \\n\
-               \# control_port_admin_password:\n\
-               \# control_port_user_password:\n\
+               \# control_port_admin_password =\n\
+               \# control_port_user_password =\n\
               \\n\
               \[TRANSPORT]\n\
               \# host is only used to print server address on start\n"
-            <> ("host: " <> T.pack host <> "\n")
-            <> ("port: " <> T.pack defaultServerPort <> "\n")
-            <> "log_tls_errors: off\n\
-               \# control_port: 5226\n\
+            <> ("host = " <> T.pack host <> "\n")
+            <> ("port = " <> T.pack defaultServerPort <> "\n")
+            <> "log_tls_errors = off\n\
+               \# control_port = 5226\n\
               \\n\
               \[FILES]\n"
-            <> ("path: " <> T.pack filesPath <> "\n")
-            <> ("storage_quota: " <> safeDecodeUtf8 (strEncode fileSizeQuota) <> "\n")
+            <> ("path = " <> T.pack filesPath <> "\n")
+            <> ("storage_quota = " <> safeDecodeUtf8 (strEncode fileSizeQuota) <> "\n")
            <> "\n\
               \[INACTIVE_CLIENTS]\n\
               \# TTL and interval to check inactive clients\n\
-               \disconnect: off\n"
-            <> ("# ttl: " <> tshow (ttl defaultInactiveClientExpiration) <> "\n")
-            <> ("# check_interval: " <> tshow (checkInterval defaultInactiveClientExpiration) <> "\n")
+               \disconnect = off\n"
+            <> ("# ttl = " <> tshow (ttl defaultInactiveClientExpiration) <> "\n")
+            <> ("# check_interval = " <> tshow (checkInterval defaultInactiveClientExpiration) <> "\n")
            <> "\n\
               \[WEB]\n\
               \# Set path to generate static mini-site for server information\n"
-            <> ("static_path: " <> T.pack (fromMaybe defaultStaticPath webStaticPath_) <> "\n\n")
+            <> ("static_path = " <> T.pack (fromMaybe defaultStaticPath webStaticPath_) <> "\n\n")
            <> "# Run an embedded HTTP server on this port.\n\
-               \# http: 8000\n\n\
+               \# http = 8000\n\n\
               \# TLS credentials for HTTPS web server on the same port as XFTP.\n\
-               \# cert: " <> T.pack (cfgPath `combine` "web.crt") <> "\n\
-               \# key: " <> T.pack (cfgPath `combine` "web.key") <> "\n"
-    runServer ini = do
+               \# cert = " <> T.pack (cfgPath `combine` "web.crt") <> "\n\
+               \# key = " <> T.pack (cfgPath `combine` "web.key") <> "\n"
+    runServer StartOptions {confirmMigrations} ini = do
      hSetBuffering stdout LineBuffering
      hSetBuffering stderr LineBuffering
      fp <- checkSavedFingerprint cfgPath defaultX509Config
@@ -183,18 +212,24 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
      printServiceInfo serverVersion srv
      let information = serverPublicInfo ini
      printSourceCode (sourceCode <$> information)
-      printXFTPConfig serverConfig
-      case webStaticPath' of
-        Just path -> do
-          let onionHost =
-                either (const Nothing) (find isOnion) $
-                  strDecode @(L.NonEmpty TransportHost) . encodeUtf8 =<< lookupValue "TRANSPORT" "host" ini
-              webHttpPort = eitherToMaybe (lookupValue "WEB" "http" ini) >>= readMaybe . T.unpack
-          generateSite serverConfig information onionHost path
-          when (isJust webHttpPort || isJust webHttpsParams') $
-            serveStaticFiles EmbeddedWebParams {webStaticPath = path, webHttpPort, webHttpsParams = webHttpsParams'}
-        Nothing -> pure ()
-      runXFTPServer serverConfig
+      case readFileStoreType ini of
+        Left err -> error err
+        Right fsType -> do
+          checkFileStoreMode ini fsType storeLogFilePath
+          runWithStoreConfig fsType ini storeLogFilePath confirmMigrations $ \storeCfg -> do
+            let cfg = serverConfig storeCfg
+            printXFTPConfig cfg
+            case webStaticPath' of
+              Just path -> do
+                let onionHost =
+                      either (const Nothing) (find isOnion) $
+                        strDecode @(L.NonEmpty TransportHost) . encodeUtf8 =<< lookupValue "TRANSPORT" "host" ini
+                    webHttpPort = eitherToMaybe (lookupValue "WEB" "http" ini) >>= readMaybe . T.unpack
+                generateSite cfg information onionHost path
+                when (isJust webHttpPort || isJust webHttpsParams') $
+                  serveStaticFiles EmbeddedWebParams {webStaticPath = path, webHttpPort, webHttpsParams = webHttpsParams'}
+              Nothing -> pure ()
+            runXFTPServer cfg
      where
        isOnion = \case THOnionHost _ -> True; _ -> False
        enableStoreLog = settingIsOn "STORE_LOG" "enable" ini
@@ -236,11 +271,13 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do

        webStaticPath' = eitherToMaybe $ T.unpack <$> lookupValue "WEB" "static_path" ini

-        serverConfig =
+        serverConfig :: XFTPStoreConfig s -> XFTPServerConfig s
+        serverConfig serverStoreCfg =
          XFTPServerConfig
            { xftpPort = T.unpack $ strictIni "TRANSPORT" "port" ini,
              controlPort = either (const Nothing) (Just . T.unpack) $ lookupValue "TRANSPORT" "control_port" ini,
              fileIdSize = 16,
+              serverStoreCfg,
              storeLogFile = enableStoreLog $> storeLogFilePath,
              filesPath = T.unpack $ strictIni "FILES" "path" ini,
              fileSizeQuota = either error unFileSize <$> strDecodeIni "FILES" "storage_quota" ini,
@@ -289,9 +326,16 @@ xftpServerCLI_ generateSite serveStaticFiles cfgPath logPath = do
 data CliCommand
  = Init InitOptions
  | OnlineCert CertOptions
-  | Start
+  | Start StartOptions
+  | Database StoreCmd
  | Delete

+data StoreCmd = SCImport | SCExport
+
+newtype StartOptions = StartOptions
+  { confirmMigrations :: MigrationConfirmation
+  }
+
 data InitOptions = InitOptions
  { enableStoreLog :: Bool,
    signAlgorithm :: SignAlgorithm,
@@ -308,7 +352,8 @@ cliCommandP cfgPath logPath iniFile =
  hsubparser
    ( command "init" (info (Init <$> initP) (progDesc $ "Initialize server - creates " <> cfgPath <> " and " <> logPath <> " directories and configuration files"))
        <> command "cert" (info (OnlineCert <$> certOptionsP) (progDesc $ "Generate new online TLS server credentials (configuration: " <> iniFile <> ")"))
-        <> command "start" (info (pure Start) (progDesc $ "Start server (configuration: " <> iniFile <> ")"))
+        <> command "start" (info (Start <$> startOptsP) (progDesc $ "Start server (configuration: " <> iniFile <> ")"))
+        <> command "database" (info (Database <$> storeCmdP) (progDesc "Import/export file store to/from PostgreSQL database"))
        <> command "delete" (info (pure Delete) (progDesc "Delete configuration and log files"))
    )
  where
@@ -375,3 +420,20 @@ cliCommandP cfgPath logPath iniFile =
              <> metavar "PATH"
          )
      pure InitOptions {enableStoreLog, signAlgorithm, ip, fqdn, filesPath, fileSizeQuota, webStaticPath}
+    startOptsP :: Parser StartOptions
+    startOptsP = do
+      confirmMigrations <-
+        option
+          parseConfirmMigrations
+          ( long "confirm-migrations"
+              <> metavar "CONFIRM_MIGRATIONS"
+              <> help "Confirm PostgreSQL database migration: up, down (default is manual confirmation)"
+              <> value MCConsole
+          )
+      pure StartOptions {confirmMigrations}
+    storeCmdP :: Parser StoreCmd
+    storeCmdP =
+      hsubparser
+        ( command "import" (info (pure SCImport) (progDesc "Import store log file into PostgreSQL database"))
+            <> command "export" (info (pure SCExport) (progDesc "Export PostgreSQL database to store log file"))
+        )
@@ -1,51 +1,53 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE KindSignatures #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TupleSections #-}
+{-# LANGUAGE TypeFamilies #-}

 module Simplex.FileTransfer.Server.Store
-  ( FileStore (..),
+  ( FSType (..),
+    SFSType (..),
+    FileStoreClass (..),
    FileRec (..),
    FileRecipient (..),
+    STMFileStore (..),
    RoundedFileTime,
-    newFileStore,
-    addFile,
-    setFilePath,
-    addRecipient,
-    deleteFile,
-    blockFile,
-    deleteRecipient,
-    expiredFilePath,
-    getFile,
-    ackFile,
    fileTimePrecision,
  )
 where

+import Data.Kind (Type)
+
 import Control.Concurrent.STM
 import Control.Monad
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Data.Int (Int64)
+import qualified Data.Map.Strict as M
+import Data.Maybe (catMaybes, isJust)
 import Data.Set (Set)
 import qualified Data.Set as S
+import Data.Word (Word32)
 import Simplex.FileTransfer.Protocol (FileInfo (..), SFileParty (..), XFTPFileId)
 import Simplex.FileTransfer.Transport (XFTPErrorType (..))
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (BlockingInfo, RcvPublicAuthKey, RecipientId, SenderId)
 import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
+import Simplex.Messaging.Server.StoreLog (StoreLog, closeStoreLog)
+import System.IO (IOMode (..))
 import Simplex.Messaging.SystemTime
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
-import Simplex.Messaging.Util (ifM, ($>>=))
+import Simplex.Messaging.Util (ifM)

-data FileStore = FileStore
-  { files :: TMap SenderId FileRec,
-    recipients :: TMap RecipientId (SenderId, RcvPublicAuthKey),
-    usedStorage :: TVar Int64
-  }
+data FSType = FSMemory | FSPostgres
+
+data SFSType :: FSType -> Type where
+  SFSMemory :: SFSType 'FSMemory
+  SFSPostgres :: SFSType 'FSPostgres

 data FileRec = FileRec
  { senderId :: SenderId,
@@ -59,28 +61,128 @@ data FileRec = FileRec
 type RoundedFileTime = RoundedSystemTime 3600

 fileTimePrecision :: Int64
-fileTimePrecision = 3600 -- truncate creation time to 1 hour
+fileTimePrecision = 3600

-data FileRecipient = FileRecipient RecipientId RcvPublicAuthKey
+data FileRecipient = FileRecipient RecipientId C.APublicAuthKey
  deriving (Show)

 instance StrEncoding FileRecipient where
  strEncode (FileRecipient rId rKey) = strEncode rId <> ":" <> strEncode rKey
  strP = FileRecipient <$> strP <* A.char ':' <*> strP

-newFileStore :: IO FileStore
-newFileStore = do
-  files <- TM.emptyIO
-  recipients <- TM.emptyIO
-  usedStorage <- newTVarIO 0
-  pure FileStore {files, recipients, usedStorage}
+class FileStoreClass s where
+  type FileStoreConfig s
+  newFileStore :: FileStoreConfig s -> IO s
+  closeFileStore :: s -> IO ()
+  addFile :: s -> SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> IO (Either XFTPErrorType ())
+  setFilePath :: s -> SenderId -> FilePath -> IO (Either XFTPErrorType ())
+  addRecipient :: s -> SenderId -> FileRecipient -> IO (Either XFTPErrorType ())
+  deleteFile :: s -> SenderId -> IO (Either XFTPErrorType ())
+  deleteFiles :: s -> [SenderId] -> IO ()
+  deleteFiles s = mapM_ (void . deleteFile s)
+  blockFile :: s -> SenderId -> BlockingInfo -> Bool -> IO (Either XFTPErrorType ())
+  deleteRecipient :: s -> RecipientId -> FileRec -> IO ()
+  getFile :: s -> SFileParty p -> XFTPFileId -> IO (Either XFTPErrorType (FileRec, C.APublicAuthKey))
+  ackFile :: s -> RecipientId -> IO (Either XFTPErrorType ())
+  expiredFiles :: s -> Int64 -> Int -> IO [(SenderId, Maybe FilePath, Word32)]
+  getUsedStorage :: s -> IO Int64
+  getFileCount :: s -> IO Int

-addFile :: FileStore -> SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> STM (Either XFTPErrorType ())
-addFile FileStore {files} sId fileInfo createdAt status =
-  ifM (TM.member sId files) (pure $ Left DUPLICATE_) $ do
-    f <- newFileRec sId fileInfo createdAt status
-    TM.insert sId f files
-    pure $ Right ()
+-- STM in-memory store
+
+data STMFileStore = STMFileStore
+  { files :: TMap SenderId FileRec,
+    recipients :: TMap RecipientId (SenderId, RcvPublicAuthKey),
+    stmStoreLog :: TVar (Maybe (StoreLog 'WriteMode))
+  }
+
+instance FileStoreClass STMFileStore where
+  type FileStoreConfig STMFileStore = ()
+
+  newFileStore () = do
+    files <- TM.emptyIO
+    recipients <- TM.emptyIO
+    stmStoreLog <- newTVarIO Nothing
+    pure STMFileStore {files, recipients, stmStoreLog}
+
+  closeFileStore STMFileStore {stmStoreLog} = readTVarIO stmStoreLog >>= mapM_ closeStoreLog
+
+  addFile STMFileStore {files} sId fileInfo createdAt status = atomically $
+    ifM (TM.member sId files) (pure $ Left DUPLICATE_) $ do
+      f <- newFileRec sId fileInfo createdAt status
+      TM.insert sId f files
+      pure $ Right ()
+
+  setFilePath st sId fPath = atomically $
+    withFile st sId $ \FileRec {filePath, fileStatus} -> do
+      readTVar filePath >>= \case
+        Just _ -> pure $ Left AUTH
+        Nothing ->
+          readTVar fileStatus >>= \case
+            EntityActive -> do
+              writeTVar filePath (Just fPath)
+              pure $ Right ()
+            _ -> pure $ Left AUTH
+
+  addRecipient st@STMFileStore {recipients} senderId (FileRecipient rId rKey) = atomically $
+    withFile st senderId $ \FileRec {recipientIds} -> do
+      rIds <- readTVar recipientIds
+      mem <- TM.member rId recipients
+      if rId `S.member` rIds || mem
+        then pure $ Left DUPLICATE_
+        else do
+          writeTVar recipientIds $! S.insert rId rIds
+          TM.insert rId (senderId, rKey) recipients
+          pure $ Right ()
+
+  deleteFile STMFileStore {files, recipients} senderId = atomically $ do
+    TM.lookupDelete senderId files >>= \case
+      Just FileRec {recipientIds} -> do
+        readTVar recipientIds >>= mapM_ (`TM.delete` recipients)
+        pure $ Right ()
+      _ -> pure $ Left AUTH
+
+  blockFile st senderId info _deleted = atomically $
+    withFile st senderId $ \FileRec {fileStatus} -> do
+      writeTVar fileStatus $! EntityBlocked info
+      pure $ Right ()
+
+  deleteRecipient STMFileStore {recipients} rId FileRec {recipientIds} = atomically $ do
+    TM.delete rId recipients
+    modifyTVar' recipientIds $ S.delete rId
+
+  getFile st party fId = atomically $ case party of
+    SFSender -> withFile st fId $ pure . Right . (\f -> (f, sndKey $ fileInfo f))
+    SFRecipient ->
+      TM.lookup fId (recipients st) >>= \case
+        Just (sId, rKey) -> withFile st sId $ pure . Right . (,rKey)
+        _ -> pure $ Left AUTH
+
+  ackFile st@STMFileStore {recipients} recipientId = atomically $ do
+    TM.lookupDelete recipientId recipients >>= \case
+      Just (sId, _) ->
+        withFile st sId $ \FileRec {recipientIds} -> do
+          modifyTVar' recipientIds $ S.delete recipientId
+          pure $ Right ()
+      _ -> pure $ Left AUTH
+
+  expiredFiles STMFileStore {files} old _limit = do
+    fs <- readTVarIO files
+    fmap catMaybes . forM (M.toList fs) $ \(sId, FileRec {fileInfo = FileInfo {size}, filePath, createdAt = RoundedSystemTime createdAt}) ->
+      if createdAt + fileTimePrecision < old
+        then do
+          path <- readTVarIO filePath
+          pure $ Just (sId, path, size)
+        else pure Nothing
+
+  getUsedStorage STMFileStore {files} = foldM addSize 0 =<< readTVarIO files
+    where
+      addSize acc FileRec {fileInfo = FileInfo {size}, filePath} =
+        ifM (isJust <$> readTVarIO filePath) (pure $! acc + fromIntegral size) (pure acc)
+
+  getFileCount STMFileStore {files} = M.size <$> readTVarIO files
+
+-- Internal STM helpers

 newFileRec :: SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> STM FileRec
 newFileRec senderId fileInfo createdAt status = do
@@ -89,75 +191,8 @@ newFileRec senderId fileInfo createdAt status = do
  fileStatus <- newTVar status
  pure FileRec {senderId, fileInfo, filePath, recipientIds, createdAt, fileStatus}

-setFilePath :: FileStore -> SenderId -> FilePath -> STM (Either XFTPErrorType ())
-setFilePath st sId fPath =
-  withFile st sId $ \FileRec {fileInfo, filePath} -> do
-    writeTVar filePath (Just fPath)
-    modifyTVar' (usedStorage st) (+ fromIntegral (size fileInfo))
-    pure $ Right ()
-
-addRecipient :: FileStore -> SenderId -> FileRecipient -> STM (Either XFTPErrorType ())
-addRecipient st@FileStore {recipients} senderId (FileRecipient rId rKey) =
-  withFile st senderId $ \FileRec {recipientIds} -> do
-    rIds <- readTVar recipientIds
-    mem <- TM.member rId recipients
-    if rId `S.member` rIds || mem
-      then pure $ Left DUPLICATE_
-      else do
-        writeTVar recipientIds $! S.insert rId rIds
-        TM.insert rId (senderId, rKey) recipients
-        pure $ Right ()
-
-- this function must be called after the file is deleted from the file system
-deleteFile :: FileStore -> SenderId -> STM (Either XFTPErrorType ())
-deleteFile FileStore {files, recipients, usedStorage} senderId = do
-  TM.lookupDelete senderId files >>= \case
-    Just FileRec {fileInfo, recipientIds} -> do
-      readTVar recipientIds >>= mapM_ (`TM.delete` recipients)
-      modifyTVar' usedStorage $ subtract (fromIntegral $ size fileInfo)
-      pure $ Right ()
-    _ -> pure $ Left AUTH
-
-- this function must be called after the file is deleted from the file system
-blockFile :: FileStore -> SenderId -> BlockingInfo -> Bool -> STM (Either XFTPErrorType ())
-blockFile st@FileStore {usedStorage} senderId info deleted =
-  withFile st senderId $ \FileRec {fileInfo, fileStatus} -> do
-    when deleted $ modifyTVar' usedStorage $ subtract (fromIntegral $ size fileInfo)
-    writeTVar fileStatus $! EntityBlocked info
-    pure $ Right ()
-
-deleteRecipient :: FileStore -> RecipientId -> FileRec -> STM ()
-deleteRecipient FileStore {recipients} rId FileRec {recipientIds} = do
-  TM.delete rId recipients
-  modifyTVar' recipientIds $ S.delete rId
-
-getFile :: FileStore -> SFileParty p -> XFTPFileId -> STM (Either XFTPErrorType (FileRec, C.APublicAuthKey))
-getFile st party fId = case party of
-  SFSender -> withFile st fId $ pure . Right . (\f -> (f, sndKey $ fileInfo f))
-  SFRecipient ->
-    TM.lookup fId (recipients st) >>= \case
-      Just (sId, rKey) -> withFile st sId $ pure . Right . (,rKey)
-      _ -> pure $ Left AUTH
-
-expiredFilePath :: FileStore -> XFTPFileId -> Int64 -> STM (Maybe (Maybe FilePath))
-expiredFilePath FileStore {files} sId old =
-  TM.lookup sId files
-    $>>= \FileRec {filePath, createdAt = RoundedSystemTime createdAt} ->
-      if createdAt + fileTimePrecision < old
-        then Just <$> readTVar filePath
-        else pure Nothing
-
-ackFile :: FileStore -> RecipientId -> STM (Either XFTPErrorType ())
-ackFile st@FileStore {recipients} recipientId = do
-  TM.lookupDelete recipientId recipients >>= \case
-    Just (sId, _) ->
-      withFile st sId $ \FileRec {recipientIds} -> do
-        modifyTVar' recipientIds $ S.delete recipientId
-        pure $ Right ()
-    _ -> pure $ Left AUTH
-
-withFile :: FileStore -> SenderId -> (FileRec -> STM (Either XFTPErrorType a)) -> STM (Either XFTPErrorType a)
-withFile FileStore {files} sId a =
+withFile :: STMFileStore -> SenderId -> (FileRec -> STM (Either XFTPErrorType a)) -> STM (Either XFTPErrorType a)
+withFile STMFileStore {files} sId a =
  TM.lookup sId files >>= \case
    Just f -> a f
    _ -> pure $ Left AUTH
@@ -0,0 +1,370 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies #-}
+
+module Simplex.FileTransfer.Server.Store.Postgres
+  ( PostgresFileStore (..),
+    importFileStore,
+    exportFileStore,
+  )
+where
+
+import qualified Control.Exception as E
+import Control.Logger.Simple
+import Control.Monad
+import Control.Monad.Except
+import Control.Monad.IO.Class
+import Control.Monad.Trans.Except (throwE)
+import Data.ByteString (ByteString)
+import qualified Data.ByteString.Char8 as B
+import Data.ByteString.Builder (Builder)
+import qualified Data.ByteString.Builder as BB
+import qualified Data.ByteString.Lazy as LB
+import Data.Functor (($>))
+import Data.Int (Int32, Int64)
+import Data.List (intersperse)
+import qualified Data.List.NonEmpty as L
+import qualified Data.Map.Strict as M
+import qualified Data.Set as S
+import Data.Text (Text)
+import Data.Word (Word32)
+import Database.PostgreSQL.Simple (Binary (..), In (..), Only (..), SqlError, (:.) (..))
+import qualified Database.PostgreSQL.Simple as DB
+import qualified Database.PostgreSQL.Simple.Copy as DB
+import Database.PostgreSQL.Simple.Errors (ConstraintViolation (..), constraintViolation)
+import Database.PostgreSQL.Simple.ToField (Action (..), ToField (..))
+import GHC.IO (catchAny)
+import Simplex.FileTransfer.Protocol (FileInfo (..), SFileParty (..))
+import Simplex.FileTransfer.Server.Store
+import Simplex.FileTransfer.Server.Store.Postgres.Config
+import Simplex.FileTransfer.Server.Store.Postgres.Migrations (xftpServerMigrations)
+import Simplex.FileTransfer.Server.StoreLog
+import Simplex.FileTransfer.Transport (XFTPErrorType (..))
+import Simplex.Messaging.Agent.Store.Postgres (closeDBStore, createDBStore)
+import Simplex.Messaging.Agent.Store.Postgres.Common (DBStore, withTransaction)
+import Simplex.Messaging.Agent.Store.Postgres.Options (DBOpts (..))
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfig (..), MigrationConfirmation (..))
+import qualified Simplex.Messaging.Crypto as C
+import Simplex.Messaging.Protocol (RcvPublicAuthKey, RecipientId, SenderId)
+import Simplex.Messaging.Transport (EntityId (..))
+import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
+import Simplex.Messaging.Server.QueueStore.Postgres ()
+import Simplex.Messaging.Server.StoreLog (openWriteStoreLog)
+import Simplex.Messaging.Util (firstRow, tshow)
+import System.Directory (renameFile)
+import System.Exit (exitFailure)
+import System.IO (IOMode (..), hFlush, stdout)
+import UnliftIO.STM
+
+data PostgresFileStore = PostgresFileStore
+  { dbStore :: DBStore,
+    dbStoreLog :: Maybe (StoreLog 'WriteMode)
+  }
+
+instance FileStoreClass PostgresFileStore where
+  type FileStoreConfig PostgresFileStore = PostgresFileStoreCfg
+
+  newFileStore PostgresFileStoreCfg {dbOpts, dbStoreLogPath, confirmMigrations} = do
+    dbStore <- either err pure =<< createDBStore dbOpts xftpServerMigrations (MigrationConfig confirmMigrations Nothing)
+    dbStoreLog <- mapM (openWriteStoreLog True) dbStoreLogPath
+    pure PostgresFileStore {dbStore, dbStoreLog}
+    where
+      err e = do
+        logError $ "STORE: newFileStore, error opening PostgreSQL database, " <> tshow e
+        exitFailure
+
+  closeFileStore PostgresFileStore {dbStore, dbStoreLog} = do
+    closeDBStore dbStore
+    mapM_ closeStoreLog dbStoreLog
+
+  addFile st sId fileInfo@FileInfo {sndKey, size, digest} createdAt status =
+    E.uninterruptibleMask_ $ runExceptT $ do
+      void $ withDB "addFile" st $ \db ->
+        E.try
+          ( DB.execute
+              db
+              "INSERT INTO files (sender_id, file_size, file_digest, sender_key, created_at, status) VALUES (?,?,?,?,?,?)"
+              (sId, (fromIntegral size :: Int32), Binary digest, Binary (C.encodePubKey sndKey), createdAt, status)
+          )
+          >>= either handleDuplicate (pure . Right)
+      withLog "addFile" st $ \s -> logAddFile s sId fileInfo createdAt status
+
+  setFilePath st sId fPath = E.uninterruptibleMask_ $ runExceptT $ do
+    assertUpdated $ withDB' "setFilePath" st $ \db ->
+      DB.execute db "UPDATE files SET file_path = ? WHERE sender_id = ? AND file_path IS NULL AND status = 'active'" (fPath, sId)
+    withLog "setFilePath" st $ \s -> logPutFile s sId fPath
+
+  addRecipient st senderId (FileRecipient rId rKey) = E.uninterruptibleMask_ $ runExceptT $ do
+    void $ withDB "addRecipient" st $ \db ->
+      E.try
+        ( DB.execute
+            db
+            "INSERT INTO recipients (recipient_id, sender_id, recipient_key) VALUES (?,?,?)"
+            (rId, senderId, Binary (C.encodePubKey rKey))
+        )
+        >>= either handleDuplicate (pure . Right)
+    withLog "addRecipient" st $ \s -> logAddRecipients s senderId (pure $ FileRecipient rId rKey)
+
+  deleteFile st sId = E.uninterruptibleMask_ $ runExceptT $ do
+    assertUpdated $ withDB' "deleteFile" st $ \db ->
+      DB.execute db "DELETE FROM files WHERE sender_id = ?" (Only sId)
+    withLog "deleteFile" st $ \s -> logDeleteFile s sId
+
+  deleteFiles st sIds = E.uninterruptibleMask_ $ do
+    withTransaction (dbStore st) $ \db ->
+      DB.execute db "DELETE FROM files WHERE sender_id IN ?" (Only (In sIds))
+    withLog "deleteFiles" st $ \s -> mapM_ (logDeleteFile s) sIds
+
+  blockFile st sId info _deleted = E.uninterruptibleMask_ $ runExceptT $ do
+    assertUpdated $ withDB' "blockFile" st $ \db ->
+      DB.execute db "UPDATE files SET status = ? WHERE sender_id = ?" (EntityBlocked info, sId)
+    withLog "blockFile" st $ \s -> logBlockFile s sId info
+
+  deleteRecipient st rId _fr =
+    void $ runExceptT $ withDB' "deleteRecipient" st $ \db ->
+      DB.execute db "DELETE FROM recipients WHERE recipient_id = ?" (Only rId)
+
+  getFile st party fId = runExceptT $ case party of
+    SFSender -> do
+      row <- loadFileRow "SELECT sender_id, file_size, file_digest, sender_key, file_path, created_at, status FROM files WHERE sender_id = ?"
+      fr <- ExceptT $ rowToFileRec row
+      pure (fr, sndKey (fileInfo fr))
+    SFRecipient -> do
+      row :. Only rcpKeyBs <-
+        loadFileRow
+          "SELECT f.sender_id, f.file_size, f.file_digest, f.sender_key, f.file_path, f.created_at, f.status, r.recipient_key FROM files f JOIN recipients r ON r.sender_id = f.sender_id WHERE r.recipient_id = ?"
+      fr <- ExceptT $ rowToFileRec row
+      rcpKey <- either (const $ throwE INTERNAL) pure $ C.decodePubKey rcpKeyBs
+      pure (fr, rcpKey)
+    where
+      loadFileRow :: DB.FromRow r => DB.Query -> ExceptT XFTPErrorType IO r
+      loadFileRow q =
+        withDB "getFile" st $ \db ->
+          firstRow id AUTH $ DB.query db q (Only fId)
+
+  ackFile st rId = E.uninterruptibleMask_ $ runExceptT $ do
+    assertUpdated $ withDB' "ackFile" st $ \db ->
+      DB.execute db "DELETE FROM recipients WHERE recipient_id = ?" (Only rId)
+    withLog "ackFile" st $ \s -> logAckFile s rId
+
+  expiredFiles st old limit =
+    fmap toResult $ withTransaction (dbStore st) $ \db ->
+      DB.query
+        db
+        "SELECT sender_id, file_path, file_size FROM files WHERE created_at + ? < ? ORDER BY created_at LIMIT ?"
+        (fileTimePrecision, old, limit)
+    where
+      toResult :: [(SenderId, Maybe FilePath, Int32)] -> [(SenderId, Maybe FilePath, Word32)]
+      toResult = map (\(sId, path, size) -> (sId, path, fromIntegral size))
+
+  getUsedStorage st =
+    withTransaction (dbStore st) $ \db -> do
+      [Only total] <- DB.query_ db "SELECT COALESCE(SUM(file_size::BIGINT), 0)::BIGINT FROM files WHERE file_path IS NOT NULL"
+      pure total
+
+  getFileCount st =
+    withTransaction (dbStore st) $ \db -> do
+      [Only count] <- DB.query_ db "SELECT COUNT(*) FROM files"
+      pure (fromIntegral (count :: Int64))
+
+-- Internal helpers
+
+mkFileRec :: SenderId -> FileInfo -> Maybe FilePath -> RoundedFileTime -> ServerEntityStatus -> IO FileRec
+mkFileRec senderId fileInfo path createdAt status = do
+  filePath <- newTVarIO path
+  recipientIds <- newTVarIO S.empty
+  fileStatus <- newTVarIO status
+  pure FileRec {senderId, fileInfo, filePath, recipientIds, createdAt, fileStatus}
+
+type FileRecRow = (SenderId, Int32, ByteString, ByteString, Maybe FilePath, RoundedFileTime, ServerEntityStatus)
+
+rowToFileRec :: FileRecRow -> IO (Either XFTPErrorType FileRec)
+rowToFileRec (sId, size, digest, sndKeyBs, path, createdAt, status) =
+  case C.decodePubKey sndKeyBs of
+    Right sndKey -> do
+      let fileInfo = FileInfo {sndKey, size = fromIntegral size, digest}
+      Right <$> mkFileRec sId fileInfo path createdAt status
+    Left _ -> pure $ Left INTERNAL
+
+-- DB helpers
+
+withDB :: forall a. Text -> PostgresFileStore -> (DB.Connection -> IO (Either XFTPErrorType a)) -> ExceptT XFTPErrorType IO a
+withDB op st action =
+  ExceptT $ E.try (withTransaction (dbStore st) action) >>= either logErr pure
+  where
+    logErr :: E.SomeException -> IO (Either XFTPErrorType a)
+    logErr e = logError ("STORE: " <> err) $> Left INTERNAL
+      where
+        err = op <> ", withDB, " <> tshow e
+
+withDB' :: Text -> PostgresFileStore -> (DB.Connection -> IO a) -> ExceptT XFTPErrorType IO a
+withDB' op st action = withDB op st $ fmap Right . action
+
+assertUpdated :: ExceptT XFTPErrorType IO Int64 -> ExceptT XFTPErrorType IO ()
+assertUpdated = (>>= \n -> when (n == 0) (throwE AUTH))
+
+handleDuplicate :: SqlError -> IO (Either XFTPErrorType a)
+handleDuplicate e = case constraintViolation e of
+  Just (UniqueViolation _) -> pure $ Left DUPLICATE_
+  Just (ForeignKeyViolation _ _) -> pure $ Left AUTH
+  _ -> E.throwIO e
+
+withLog :: MonadIO m => Text -> PostgresFileStore -> (StoreLog 'WriteMode -> IO ()) -> m ()
+withLog op PostgresFileStore {dbStoreLog} action =
+  forM_ dbStoreLog $ \sl -> liftIO $ action sl `catchAny` \e ->
+    logWarn $ "STORE: " <> op <> ", withLog, " <> tshow e
+
+-- Import: StoreLog -> PostgreSQL
+
+importFileStore :: FilePath -> PostgresFileStoreCfg -> IO ()
+importFileStore storeLogFilePath dbCfg = do
+  putStrLn $ "Reading store log: " <> storeLogFilePath
+  stmStore <- newFileStore () :: IO STMFileStore
+  sl <- readWriteFileStore storeLogFilePath stmStore
+  closeStoreLog sl
+  allFiles <- readTVarIO (files stmStore)
+  allRcps <- readTVarIO (recipients stmStore)
+  let fileCount = M.size allFiles
+      rcpCount = M.size allRcps
+  putStrLn $ "Loaded " <> show fileCount <> " files, " <> show rcpCount <> " recipients."
+  let dbCfg' = dbCfg {dbOpts = (dbOpts dbCfg) {createSchema = True}, confirmMigrations = MCYesUp}
+  pgStore <- newFileStore dbCfg' :: IO PostgresFileStore
+  existingCount <- getFileCount pgStore
+  when (existingCount > 0) $ do
+    putStrLn $ "WARNING: database already contains " <> show existingCount <> " files. Import will fail on duplicate keys."
+    putStrLn "Drop the existing schema first or use a fresh database."
+    exitFailure
+  putStrLn "Importing files..."
+  fCnt <- withTransaction (dbStore pgStore) $ \db -> do
+    DB.copy_
+      db
+      "COPY files (sender_id, file_size, file_digest, sender_key, file_path, created_at, status) FROM STDIN WITH (FORMAT csv)"
+    iforM_ (M.toList allFiles) $ \i (sId, fr) -> do
+      DB.putCopyData db =<< fileRecToCSV sId fr
+      when (i > 0 && i `mod` 10000 == 0) $ putStr ("  " <> show i <> " files\r") >> hFlush stdout
+    DB.putCopyEnd db
+    [Only cnt] <- DB.query_ db "SELECT COUNT(*) FROM files"
+    pure (cnt :: Int64)
+  putStrLn $ "Imported " <> show fCnt <> " files."
+  putStrLn "Importing recipients..."
+  rCnt <- withTransaction (dbStore pgStore) $ \db -> do
+    DB.copy_
+      db
+      "COPY recipients (recipient_id, sender_id, recipient_key) FROM STDIN WITH (FORMAT csv)"
+    iforM_ (M.toList allRcps) $ \i (rId, (sId, rKey)) -> do
+      DB.putCopyData db $ recipientToCSV rId sId rKey
+      when (i > 0 && i `mod` 10000 == 0) $ putStr ("  " <> show i <> " recipients\r") >> hFlush stdout
+    DB.putCopyEnd db
+    [Only cnt] <- DB.query_ db "SELECT COUNT(*) FROM recipients"
+    pure (cnt :: Int64)
+  putStrLn $ "Imported " <> show rCnt <> " recipients."
+  when (fromIntegral fileCount /= fCnt) $
+    putStrLn $ "WARNING: expected " <> show fileCount <> " files, got " <> show fCnt
+  when (fromIntegral rcpCount /= rCnt) $
+    putStrLn $ "WARNING: expected " <> show rcpCount <> " recipients, got " <> show rCnt
+  closeFileStore pgStore
+  renameFile storeLogFilePath (storeLogFilePath <> ".bak")
+  putStrLn $ "Store log renamed to " <> storeLogFilePath <> ".bak"
+
+-- Export: PostgreSQL -> StoreLog
+
+exportFileStore :: FilePath -> PostgresFileStoreCfg -> IO ()
+exportFileStore storeLogFilePath dbCfg = do
+  pgStore <- newFileStore dbCfg :: IO PostgresFileStore
+  sl <- openWriteStoreLog False storeLogFilePath
+  -- Fold 1: stream files, write FNEW + FPUT per file
+  putStrLn "Exporting files..."
+  !fCnt <- withTransaction (dbStore pgStore) $ \db ->
+    DB.fold_
+      db
+      "SELECT sender_id, file_size, file_digest, sender_key, file_path, created_at, status FROM files ORDER BY created_at"
+      (0 :: Int)
+      ( \(!fc) (sId, size :: Int32, digest :: ByteString, sndKeyBs :: ByteString, path :: Maybe String, createdAt, status) ->
+          case C.decodePubKey sndKeyBs of
+            Right sndKey -> do
+              let fileInfo = FileInfo {sndKey, size = fromIntegral size, digest}
+              logAddFile sl sId fileInfo createdAt status
+              forM_ path $ logPutFile sl sId
+              pure (fc + 1)
+            Left _ -> do
+              putStrLn $ "WARNING: invalid sender key for " <> show sId
+              pure fc
+      )
+  -- Fold 2: stream recipients ordered by sender_id, flush FADD on sender change
+  putStrLn "Exporting recipients..."
+  !rCnt <- withTransaction (dbStore pgStore) $ \db ->
+    DB.fold_
+      db
+      "SELECT sender_id, recipient_id, recipient_key FROM recipients ORDER BY sender_id"
+      (Nothing :: Maybe SenderId, [] :: [FileRecipient], 0 :: Int)
+      ( \(!prevSId, !buf, !rc) (sId, rId, rKeyBs :: ByteString) ->
+          case C.decodePubKey rKeyBs of
+            Right rKey -> do
+              let rcp = FileRecipient rId rKey
+              case prevSId of
+                Just prev | prev /= sId -> do
+                  forM_ (L.nonEmpty buf) $ logAddRecipients sl prev
+                  pure (Just sId, [rcp], rc + length buf)
+                _ -> pure (Just sId, rcp : buf, rc)
+            Left _ -> putStrLn ("WARNING: invalid recipient key for " <> show rId) $> (prevSId, buf, rc)
+      )
+      >>= \(lastSId, buf, rc) -> do
+        forM_ lastSId $ \sId -> forM_ (L.nonEmpty buf) $ logAddRecipients sl sId
+        pure (rc + length buf)
+  closeStoreLog sl
+  closeFileStore pgStore
+  putStrLn $ "Exported " <> show fCnt <> " files, " <> show rCnt <> " recipients to " <> storeLogFilePath
+
+-- CSV helpers for COPY protocol
+
+iforM_ :: Monad m => [a] -> (Int -> a -> m ()) -> m ()
+iforM_ xs f = zipWithM_ f [0 ..] xs
+
+fileRecToCSV :: SenderId -> FileRec -> IO ByteString
+fileRecToCSV sId FileRec {fileInfo = FileInfo {sndKey, size, digest}, filePath, createdAt, fileStatus} = do
+  path <- readTVarIO filePath
+  status <- readTVarIO fileStatus
+  pure $ LB.toStrict $ BB.toLazyByteString $ mconcat (BB.char7 ',' `intersperse` fields path status) <> BB.char7 '\n'
+  where
+    fields path status =
+      [ renderField (toField (Binary (unEntityId sId))),
+        renderField (toField (fromIntegral size :: Int32)),
+        renderField (toField (Binary digest)),
+        renderField (toField (Binary (C.encodePubKey sndKey))),
+        nullable (toField <$> path),
+        renderField (toField createdAt),
+        quotedField (toField status)
+      ]
+
+recipientToCSV :: RecipientId -> SenderId -> RcvPublicAuthKey -> ByteString
+recipientToCSV rId sId rKey =
+  LB.toStrict $ BB.toLazyByteString $ mconcat (BB.char7 ',' `intersperse` fields) <> BB.char7 '\n'
+  where
+    fields =
+      [ renderField (toField (Binary (unEntityId rId))),
+        renderField (toField (Binary (unEntityId sId))),
+        renderField (toField (Binary (C.encodePubKey rKey)))
+      ]
+
+renderField :: Action -> Builder
+renderField = \case
+  Plain bld -> bld
+  Escape s -> BB.byteString s
+  EscapeByteA s -> BB.string7 "\\x" <> BB.byteStringHex s
+  EscapeIdentifier s -> BB.byteString s
+  Many as -> mconcat (map renderField as)
+
+nullable :: Maybe Action -> Builder
+nullable = maybe mempty renderField
+
+quotedField :: Action -> Builder
+quotedField a = BB.char7 '"' <> escapeQuotes (renderField a) <> BB.char7 '"'
+  where
+    escapeQuotes bld =
+      let bs = LB.toStrict $ BB.toLazyByteString bld
+       in BB.byteString $ B.concatMap (\c -> if c == '"' then "\"\"" else B.singleton c) bs
@@ -0,0 +1,25 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Simplex.FileTransfer.Server.Store.Postgres.Config
+  ( PostgresFileStoreCfg (..),
+    defaultXFTPDBOpts,
+  )
+where
+
+import Simplex.Messaging.Agent.Store.Postgres.Options (DBOpts (..))
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation)
+
+data PostgresFileStoreCfg = PostgresFileStoreCfg
+  { dbOpts :: DBOpts,
+    dbStoreLogPath :: Maybe FilePath,
+    confirmMigrations :: MigrationConfirmation
+  }
+
+defaultXFTPDBOpts :: DBOpts
+defaultXFTPDBOpts =
+  DBOpts
+    { connstr = "postgresql://xftp@/xftp_server_store",
+      schema = "xftp_server",
+      poolSize = 10,
+      createSchema = False
+    }
@@ -0,0 +1,47 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.FileTransfer.Server.Store.Postgres.Migrations
+  ( xftpServerMigrations,
+  )
+where
+
+import Data.List (sortOn)
+import Data.Text (Text)
+import Simplex.Messaging.Agent.Store.Shared
+import Text.RawString.QQ (r)
+
+xftpSchemaMigrations :: [(String, Text, Maybe Text)]
+xftpSchemaMigrations =
+  [ ("20260325_initial", m20260325_initial, Nothing)
+  ]
+
+-- | The list of migrations in ascending order by date
+xftpServerMigrations :: [Migration]
+xftpServerMigrations = sortOn name $ map migration xftpSchemaMigrations
+  where
+    migration (name, up, down) = Migration {name, up, down = down}
+
+m20260325_initial :: Text
+m20260325_initial =
+  [r|
+CREATE TABLE files (
+  sender_id BYTEA NOT NULL PRIMARY KEY,
+  file_size INTEGER NOT NULL,
+  file_digest BYTEA NOT NULL,
+  sender_key BYTEA NOT NULL,
+  file_path TEXT,
+  created_at BIGINT NOT NULL,
+  status TEXT NOT NULL DEFAULT 'active'
+);
+
+CREATE TABLE recipients (
+  recipient_id BYTEA NOT NULL PRIMARY KEY,
+  sender_id BYTEA NOT NULL REFERENCES files ON DELETE CASCADE,
+  recipient_key BYTEA NOT NULL
+);
+
+CREATE INDEX idx_recipients_sender_id ON recipients (sender_id);
+CREATE INDEX idx_files_created_at ON files (created_at);
+|]
@@ -10,6 +10,7 @@ module Simplex.FileTransfer.Server.StoreLog
    FileStoreLogRecord (..),
    closeStoreLog,
    readWriteFileStore,
+    writeFileStore,
    logAddFile,
    logPutFile,
    logAddRecipients,
@@ -32,6 +33,7 @@ import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as M
 import Simplex.FileTransfer.Protocol (FileInfo (..))
 import Simplex.FileTransfer.Server.Store
+import Simplex.FileTransfer.Transport (XFTPErrorType (..))
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (BlockingInfo, RcvPublicAuthKey, RecipientId, SenderId)
 import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
@@ -87,20 +89,22 @@ logBlockFile s fId = logFileStoreRecord s . BlockFile fId
 logAckFile :: StoreLog 'WriteMode -> RecipientId -> IO ()
 logAckFile s = logFileStoreRecord s . AckFile

-readWriteFileStore :: FilePath -> FileStore -> IO (StoreLog 'WriteMode)
+readWriteFileStore :: FilePath -> STMFileStore -> IO (StoreLog 'WriteMode)
 readWriteFileStore = readWriteStoreLog readFileStore writeFileStore

-readFileStore :: FilePath -> FileStore -> IO ()
+readFileStore :: FilePath -> STMFileStore -> IO ()
 readFileStore f st = mapM_ (addFileLogRecord . LB.toStrict) . LB.lines =<< LB.readFile f
  where
    addFileLogRecord s = case strDecode s of
      Left e -> B.putStrLn $ "Log parsing error (" <> B.pack e <> "): " <> B.take 100 s
      Right lr ->
-        atomically (addToStore lr) >>= \case
+        addToStore lr >>= \case
          Left e -> B.putStrLn $ "Log processing error (" <> bshow e <> "): " <> B.take 100 s
          _ -> pure ()
    addToStore = \case
-      AddFile sId file createdAt status -> addFile st sId file createdAt status
+      AddFile sId file createdAt status
+        | size file > 0 -> addFile st sId file createdAt status
+        | otherwise -> pure $ Left SIZE
      PutFile qId path -> setFilePath st qId path
      AddRecipients sId rcps -> runExceptT $ addRecipients sId rcps
      DeleteFile sId -> deleteFile st sId
@@ -108,8 +112,8 @@ readFileStore f st = mapM_ (addFileLogRecord . LB.toStrict) . LB.lines =<< LB.re
      AckFile rId -> ackFile st rId
    addRecipients sId rcps = mapM_ (ExceptT . addRecipient st sId) rcps

-writeFileStore :: StoreLog 'WriteMode -> FileStore -> IO ()
-writeFileStore s FileStore {files, recipients} = do
+writeFileStore :: StoreLog 'WriteMode -> STMFileStore -> IO ()
+writeFileStore s STMFileStore {files, recipients} = do
  allRcps <- readTVarIO recipients
  readTVarIO files >>= mapM_ (logFile allRcps)
  where
@@ -46,6 +46,7 @@ import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Parsers
 import Simplex.Messaging.Protocol (XFTPServer)
+import Simplex.Messaging.Util (safeDecodeUtf8, (<$$>))
 import System.FilePath ((</>))

 type RcvFileId = ByteString -- Agent entity ID
@@ -65,7 +66,8 @@ data FileHeader = FileHeader
 instance Encoding FileHeader where
  smpEncode FileHeader {fileName, fileExtra} = smpEncode (fileName, fileExtra)
  smpP = do
-    (fileName, fileExtra) <- smpP
+    fileName <- safeDecodeUtf8 <$> smpP
+    fileExtra <- safeDecodeUtf8 <$$> smpP
    pure FileHeader {fileName, fileExtra}

 type DBRcvFileId = Int64
@@ -1,19 +1,26 @@
 module Simplex.FileTransfer.Util
  ( uniqueCombine,
+    safeFileNameStr,
    removePath,
  )
 where

 import Simplex.Messaging.Util (ifM, whenM)
-import System.FilePath (splitExtensions, (</>))
+import System.FilePath (makeValid, splitExtensions, takeFileName, (</>))
 import UnliftIO
 import UnliftIO.Directory

+safeFileNameStr :: String -> String
+safeFileNameStr = notDots . makeValid . takeFileName
+  where
+    notDots n = if n == "." || n == ".." then "_" else n
+
+-- | The file name is sanitized, so the combined path cannot escape the folder.
 uniqueCombine :: MonadIO m => FilePath -> String -> m FilePath
 uniqueCombine filePath fileName = tryCombine (0 :: Int)
  where
    tryCombine n =
-      let (name, ext) = splitExtensions fileName
+      let (name, ext) = splitExtensions $ safeFileNameStr fileName
          suffix = if n == 0 then "" else "_" <> show n
          f = filePath </> (name <> suffix <> ext)
       in ifM (doesPathExist f) (tryCombine $ n + 1) (pure f)
@@ -68,6 +68,8 @@ module Simplex.Messaging.Agent.Client
    deleteQueueLink,
    secureGetQueueLink,
    getQueueLink,
+    resolveName,
+    getNextNameServer,
    enableQueueNotifications,
    EnableQueueNtfReq (..),
    enableQueuesNtfs,
@@ -267,6 +269,7 @@ import Simplex.Messaging.Protocol
    NetworkError (..),
    MsgFlags (..),
    MsgId,
+    NameRecord,
    NtfServer,
    NtfServerWithAuth,
    ProtoServer,
@@ -301,11 +304,12 @@ import Simplex.Messaging.Protocol
 import qualified Simplex.Messaging.Protocol as SMP
 import Simplex.Messaging.Protocol.Types
 import Simplex.Messaging.Server.QueueStore.QueueInfo
+import Simplex.Messaging.Server.Information (ServerPublicInfo)
 import Simplex.Messaging.Session
 import Simplex.Messaging.SystemTime
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
-import Simplex.Messaging.Transport (HandshakeError (..), SMPServiceRole (..), SMPVersion, ServiceCredentials (..), SessionId, THClientService' (..), THandleAuth (..), THandleParams (sessionId, thAuth, thVersion), TransportError (..), TransportPeer (..), sndAuthKeySMPVersion, shortLinksSMPVersion, newNtfCredsSMPVersion)
+import Simplex.Messaging.Transport (HandshakeError (..), SMPServiceRole (..), SMPVersion, ServiceCredentials (..), SessionId, THClientService' (..), THandleAuth (..), THandleParams (sessionId, thAuth, thVersion, serverInfo), TransportError (..), TransportPeer (..), shortLinksSMPVersion, newNtfCredsSMPVersion)
 import Simplex.Messaging.Transport.Client (TransportHost (..))
 import Simplex.Messaging.Transport.Credentials
 import Simplex.Messaging.Util
@@ -381,6 +385,7 @@ data AgentClient = AgentClient
    clientId :: Int,
    agentEnv :: Env,
    proxySessTs :: TVar UTCTime,
+    serviceRequests :: TMap ConnId (TMVar (Either AgentErrorType SMP.MsgBody)),
    smpServersStats :: TMap (UserId, SMPServer) AgentSMPServerStats,
    xftpServersStats :: TMap (UserId, XFTPServer) AgentXFTPServerStats,
    ntfServersStats :: TMap (UserId, NtfServer) AgentNtfServerStats,
@@ -544,6 +549,7 @@ newAgentClient clientId InitialAgentServers {smp, ntf, xftp, netCfg, useServices
  invLocks <- TM.emptyIO
  deleteLock <- createLockIO
  smpSubWorkers <- TM.emptyIO
+  serviceRequests <- TM.emptyIO
  smpServersStats <- TM.emptyIO
  xftpServersStats <- TM.emptyIO
  ntfServersStats <- TM.emptyIO
@@ -589,6 +595,7 @@ newAgentClient clientId InitialAgentServers {smp, ntf, xftp, netCfg, useServices
        clientId,
        agentEnv,
        proxySessTs,
+        serviceRequests,
        smpServersStats,
        xftpServersStats,
        ntfServersStats,
@@ -625,9 +632,7 @@ getServiceCredentials c userId srv =
            Just service -> pure service
            Nothing -> do
              cred <- genCredentials g Nothing (25, 24 * 999999) "simplex"
-              let tlsCreds = tlsCredentials [cred]
-              createClientService db userId srv tlsCreds
-              pure (tlsCreds, Nothing)
+              createClientService db userId srv $ tlsCredentials [cred]
      serviceSignKey <- liftEitherWith INTERNAL $ C.x509ToPrivate' $ snd serviceCreds
      let creds = ServiceCredentials {serviceRole = SRMessaging, serviceCreds, serviceCertHash = XV.Fingerprint kh, serviceSignKey}
      pure (creds, serviceId_)
@@ -676,8 +681,7 @@ getSMPServerClient :: AgentClient -> NetworkRequestMode -> SMPTransportSession -
 getSMPServerClient c@AgentClient {active, smpClients, workerSeq} nm tSess = do
  unlessM (readTVarIO active) $ throwE INACTIVE
  ts <- liftIO getCurrentTime
-  atomically (getSessVar workerSeq tSess smpClients ts)
-    >>= either newClient (waitForProtocolClient c nm tSess smpClients)
+  withGetSessVar workerSeq tSess smpClients ts newClient (waitForProtocolClient c nm tSess smpClients)
  where
    newClient v = do
      prs <- liftIO TM.emptyIO
@@ -688,33 +692,29 @@ getSMPProxyClient c@AgentClient {active, smpClients, smpProxiedRelays, workerSeq
  unlessM (readTVarIO active) $ throwE INACTIVE
  proxySrv <- maybe (getNextServer c userId proxySrvs [destSrv]) pure proxySrv_
  ts <- liftIO getCurrentTime
-  atomically (getClientVar proxySrv ts) >>= \(tSess, auth, v) ->
-    either (newProxyClient tSess auth ts) (waitForProxyClient tSess auth) v
+  (tSess, auth) <- atomically $ proxiedTransportSession proxySrv
+  withGetSessVar workerSeq tSess smpClients ts (newProxyClient tSess auth ts) (waitForProxyClient tSess auth)
  where
-    getClientVar :: SMPServerWithAuth -> UTCTime -> STM (SMPTransportSession, Maybe SMP.BasicAuth, Either SMPClientVar SMPClientVar)
-    getClientVar proxySrv ts = do
+    proxiedTransportSession :: SMPServerWithAuth -> STM (SMPTransportSession, Maybe SMP.BasicAuth)
+    proxiedTransportSession proxySrv = do
      ProtoServerWithAuth srv auth <- TM.lookup destSess smpProxiedRelays >>= maybe (TM.insert destSess proxySrv smpProxiedRelays $> proxySrv) pure
-      let tSess = (userId, srv, qId)
-      (tSess,auth,) <$> getSessVar workerSeq tSess smpClients ts
+      pure ((userId, srv, qId), auth)
    newProxyClient :: SMPTransportSession -> Maybe SMP.BasicAuth -> UTCTime -> SMPClientVar -> AM (SMPConnectedClient, Either AgentErrorType ProxiedRelay)
    newProxyClient tSess auth ts v = do
      prs <- liftIO TM.emptyIO
-      -- we do not need to check if it is a new proxied relay session,
-      -- as the client is just created and there are no sessions yet
-      rv <- atomically $ either id id <$> getSessVar workerSeq destSrv prs ts
      clnt <- smpConnectClient c nm tSess prs v
-      (clnt,) <$> newProxiedRelay clnt auth rv
+      -- the relay var is always new (the client is just created and has no sessions yet)
+      sess <- withGetSessVar workerSeq destSrv prs ts (newProxiedRelay clnt auth) (waitForProxiedRelay tSess)
+      pure (clnt, sess)
    waitForProxyClient :: SMPTransportSession -> Maybe SMP.BasicAuth -> SMPClientVar -> AM (SMPConnectedClient, Either AgentErrorType ProxiedRelay)
    waitForProxyClient tSess auth v = do
      clnt@(SMPConnectedClient _ prs) <- waitForProtocolClient c nm tSess smpClients v
      ts <- liftIO getCurrentTime
-      sess <-
-        atomically (getSessVar workerSeq destSrv prs ts)
-          >>= either (newProxiedRelay clnt auth) (waitForProxiedRelay tSess)
+      sess <- withGetSessVar workerSeq destSrv prs ts (newProxiedRelay clnt auth) (waitForProxiedRelay tSess)
      pure (clnt, sess)
    newProxiedRelay :: SMPConnectedClient -> Maybe SMP.BasicAuth -> ProxiedRelayVar -> AM (Either AgentErrorType ProxiedRelay)
    newProxiedRelay (SMPConnectedClient smp prs) proxyAuth rv =
-      tryAllErrors (liftClient SMP (clientServer smp) $ connectSMPProxiedRelay smp nm destSrv proxyAuth) >>= \case
+      tryAllErrors (liftClient proxyRelayError (clientServer smp) $ connectSMPProxiedRelay smp nm destSrv proxyAuth) >>= \case
        Right sess -> do
          atomically $ putTMVar (sessionVar rv) (Right sess)
          pure $ Right sess
@@ -725,6 +725,18 @@ getSMPProxyClient c@AgentClient {active, smpClients, smpProxiedRelays, workerSeq
              TM.delete destSess smpProxiedRelays
            putTMVar (sessionVar rv) (Left e)
            pure $ Left e
+      where
+        -- proxy reports BROKER errors about the relay, not about its own connection,
+        -- so they include both addresses, same as PFWD errors.
+        proxyRelayError :: HostName -> ErrorType -> AgentErrorType
+        proxyRelayError proxyHost = \case
+          e@(SMP.PROXY (SMP.BROKER _)) ->
+            PROXY
+              { proxyServer = protocolClientServer smp,
+                relayServer = B.unpack $ strEncode destSrv,
+                proxyErr = ProxyProtocolError e
+              }
+          e -> SMP proxyHost e
    waitForProxiedRelay :: SMPTransportSession -> ProxiedRelayVar -> AM (Either AgentErrorType ProxiedRelay)
    waitForProxiedRelay (_, srv, _) rv = do
      NetworkConfig {tcpConnectTimeout} <- getNetworkConfig c
@@ -810,13 +822,17 @@ resubscribeSMPSession c@AgentClient {smpSubWorkers, workerSeq} tSess = do
        (pure Nothing) -- prevent race with cleanup and adding pending queues in another call
        (Just <$> getSessVar workerSeq tSess smpSubWorkers ts)
    newSubWorker v = do
-      a <- async $ void (E.tryAny runSubWorker) >> atomically (cleanup v)
+      a <- async $ void $ E.tryAny $ runSubWorker v
      atomically $ putTMVar (sessionVar v) a
-    runSubWorker = do
+    runSubWorker v = do
      ri <- asks $ reconnectInterval . config
      withRetryForeground ri isForeground (isNetworkOnline c) $ \_ loop -> do
-        (pendingSubs, pendingSS) <- atomically $ SS.getPendingSubs tSess $ currentSubs c
-        unless (M.null pendingSubs && isNothing pendingSS) $ do
+        pending_ <- atomically $ do
+          pending@(pendingSubs, pendingSS) <- SS.getPendingSubs tSess $ currentSubs c
+          if M.null pendingSubs && isNothing pendingSS
+            then cleanup v $> Nothing
+            else pure $ Just pending
+        forM_ pending_ $ \(pendingSubs, pendingSS) -> do
          liftIO $ waitUntilForeground c
          liftIO $ waitForUserNetwork c
          mapM_ (handleNotify . void . runExceptT . resubscribeClientService c tSess) pendingSS
@@ -844,10 +860,7 @@ getNtfServerClient :: AgentClient -> NetworkRequestMode -> NtfTransportSession -
 getNtfServerClient c@AgentClient {active, ntfClients, workerSeq, proxySessTs, presetDomains} nm tSess@(_, srv, _) = do
  unlessM (readTVarIO active) $ throwE INACTIVE
  ts <- liftIO getCurrentTime
-  atomically (getSessVar workerSeq tSess ntfClients ts)
-    >>= either
-      (newProtocolClient c tSess ntfClients connectClient)
-      (waitForProtocolClient c nm tSess ntfClients)
+  withGetSessVar workerSeq tSess ntfClients ts (newProtocolClient c tSess ntfClients connectClient) (waitForProtocolClient c nm tSess ntfClients)
  where
    connectClient :: NtfClientVar -> AM NtfClient
    connectClient v = do
@@ -868,10 +881,7 @@ getXFTPServerClient :: AgentClient -> XFTPTransportSession -> AM XFTPClient
 getXFTPServerClient c@AgentClient {active, xftpClients, workerSeq, proxySessTs, presetDomains} tSess@(_, srv, _) = do
  unlessM (readTVarIO active) $ throwE INACTIVE
  ts <- liftIO getCurrentTime
-  atomically (getSessVar workerSeq tSess xftpClients ts)
-    >>= either
-      (newProtocolClient c tSess xftpClients connectClient)
-      (waitForProtocolClient c NRMBackground tSess xftpClients)
+  withGetSessVar workerSeq tSess xftpClients ts (newProtocolClient c tSess xftpClients connectClient) (waitForProtocolClient c NRMBackground tSess xftpClients)
  where
    connectClient :: XFTPClientVar -> AM XFTPClient
    connectClient v = do
@@ -1287,7 +1297,7 @@ data ProtocolTestFailure = ProtocolTestFailure
  }
  deriving (Eq, Show)

-runSMPServerTest :: AgentClient -> NetworkRequestMode -> UserId -> SMPServerWithAuth -> AM' (Maybe ProtocolTestFailure)
+runSMPServerTest :: AgentClient -> NetworkRequestMode -> UserId -> SMPServerWithAuth -> AM' (Either ProtocolTestFailure (Maybe (Either String ServerPublicInfo)))
 runSMPServerTest c@AgentClient {presetDomains} nm userId (ProtoServerWithAuth srv auth) = do
  cfg <- getClientConfig c smpCfg
  C.AuthAlg ra <- asks $ rcvAuthAlg . config
@@ -1309,8 +1319,8 @@ runSMPServerTest c@AgentClient {presetDomains} nm userId (ProtoServerWithAuth sr
              _ -> secureSMPQueue smp nm rpKey rcvId sKey
          liftError (testErr TSDeleteQueue) $ deleteSMPQueue smp nm rpKey rcvId
        ok <- netTimeoutInt (tcpTimeout $ networkConfig cfg) nm `timeout` closeProtocolClient smp
-        pure $ either Just (const Nothing) r <|> maybe (Just (ProtocolTestFailure TSDisconnect $ BROKER addr TIMEOUT)) (const Nothing) ok
-      Left e -> pure (Just $ testErr TSConnect e)
+        pure $ r >> maybe (Left (ProtocolTestFailure TSDisconnect $ BROKER addr TIMEOUT)) (const $ Right $ serverInfo (thParams smp)) ok
+      Left e -> pure $ Left (testErr TSConnect e)
  where
    addr = B.unpack $ strEncode srv
    testErr :: ProtocolTestStep -> SMPClientError -> ProtocolTestFailure
@@ -1510,9 +1520,7 @@ newRcvQueue_ c nm userId connId (ProtoServerWithAuth srv auth) vRange cqrd enabl
          if sndId == sndId' && lnkId == lnkId'
            then pure $ Just $ ShortLinkCreds lnkId linkKey privSigKey Nothing (fst d)
            else newErr "different sender or link IDs"
-      (_, Nothing) -> case linkId of
-        Nothing | v < sndAuthKeySMPVersion -> pure Nothing
-        _ -> newErr "unexpected link ID"
+      (_, Nothing) -> newErr "unexpected link ID"
      _ -> newErr "unexpected queue mode"
      where
        v = thVersion thParams'
@@ -1659,9 +1667,15 @@ checkQueues c = fmap partitionEithers . mapM checkQueue
 resubscribeSessQueues :: AgentClient -> SMPTransportSession -> [RcvQueueSub] -> AM' ()
 resubscribeSessQueues _ _ [] = pure ()
 resubscribeSessQueues c tSess qs = do
+  batchSize <- asks $ subsBatchSize . config
  (errs, qs_) <- checkQueues c qs
-  forM_ (L.nonEmpty qs_) $ \qs' -> void $ subscribeSessQueues_ c True (tSess, qs')
+  subscribeChunks $ toChunks batchSize qs_
  forM_ (L.nonEmpty errs) $ notifySub c . ERRS . L.map (first qConnId)
+  where
+    subscribeChunks [] = pure ()
+    subscribeChunks (qs' : rest) = do
+      (_, active) <- subscribeSessQueues_ c True (tSess, qs')
+      when active $ subscribeChunks rest

 subscribeSessQueues_ :: AgentClient -> Bool -> (SMPTransportSession, NonEmpty RcvQueueSub) -> AM' (BatchResponses RcvQueueSub AgentErrorType (Maybe ServiceId), Bool)
 subscribeSessQueues_ c withEvents qs = sendClientBatch_ "SUB" False subscribe_ c NRMBackground qs
@@ -1684,7 +1698,7 @@ subscribeSessQueues_ c withEvents qs = sendClientBatch_ "SUB" False subscribe_ c
          unless (null notices) $ takeTMVar $ clientNoticesLock c
          pure r
        unless (null serviceQs) $ void $
-          processRcvServiceAssocs c serviceQs `runReaderT` agentEnv c
+          processRcvServiceAssocs c srv serviceQs `runReaderT` agentEnv c
        unless (null notices) $ void $
          (processClientNotices c tSess notices `runReaderT` agentEnv c)
            `E.finally` atomically (putTMVar (clientNoticesLock c) ())
@@ -1706,11 +1720,11 @@ subscribeSessQueues_ c withEvents qs = sendClientBatch_ "SUB" False subscribe_ c
        tSess = transportSession' smp
        sessId = sessionId $ thParams smp

-processRcvServiceAssocs :: SMPQueue q => AgentClient -> [q] -> AM' ()
-processRcvServiceAssocs _ [] = pure ()
-processRcvServiceAssocs c serviceQs =
-  withStore' c (`setRcvServiceAssocs` serviceQs) `catchAllErrors'` \e -> do
-    logError $ "processClientNotices error: " <> tshow e
+processRcvServiceAssocs :: SMPQueue q => AgentClient -> SMPServer -> [q] -> AM' ()
+processRcvServiceAssocs _ _ [] = pure ()
+processRcvServiceAssocs c srv serviceQs =
+  withStore' c (\db -> setRcvServiceAssocs db srv serviceQs) `catchAllErrors'` \e -> do
+    logError $ "processRcvServiceAssocs error: " <> tshow e
    notifySub' c "" $ ERR e

 processClientNotices :: AgentClient -> SMPTransportSession -> [(RcvQueueSub, Maybe ClientNotice)] -> AM' ()
@@ -1913,17 +1927,10 @@ sendConfirmation c nm sq@SndQueue {userId, server, connId, sndId, queueMode, snd
  sendOrProxySMPMessage c nm userId server connId "<CONF>" spKey sndId (MsgFlags {notification = True}) msg
 sendConfirmation _ _ _ _ = throwE $ INTERNAL "sendConfirmation called without snd_queue public key(s) in the database"

-sendInvitation :: AgentClient -> NetworkRequestMode -> UserId -> ConnId -> Compatible SMPQueueInfo -> Compatible VersionSMPA -> ConnectionRequestUri 'CMInvitation -> ConnInfo -> AM (Maybe SMPServer)
-sendInvitation c nm userId connId (Compatible (SMPQueueInfo v SMPQueueAddress {smpServer, senderId, dhPublicKey})) (Compatible agentVersion) connReq connInfo = do
-  msg <- mkInvitation
+sendInvitation :: AgentClient -> NetworkRequestMode -> UserId -> ConnId -> Compatible SMPQueueInfo -> AgentMsgEnvelope -> AM (Maybe SMPServer)
+sendInvitation c nm userId connId (Compatible (SMPQueueInfo v SMPQueueAddress {smpServer, senderId, dhPublicKey})) agentEnvelope = do
+  msg <- agentCbEncryptOnce v dhPublicKey . smpEncode $ SMP.ClientMessage SMP.PHEmpty (smpEncode agentEnvelope)
  sendOrProxySMPMessage c nm userId smpServer connId "<INV>" Nothing senderId (MsgFlags {notification = True}) msg
-  where
-    mkInvitation :: AM ByteString
-    -- this is only encrypted with per-queue E2E, not with double ratchet
-    mkInvitation = do
-      let agentEnvelope = AgentInvitation {agentVersion, connReq, connInfo}
-      agentCbEncryptOnce v dhPublicKey . smpEncode $
-        SMP.ClientMessage SMP.PHEmpty (smpEncode agentEnvelope)

 getQueueMessage :: AgentClient -> RcvQueue -> AM (Maybe SMPMsgMeta)
 getQueueMessage c rq@RcvQueue {server, rcvId, rcvPrivateKey} = do
@@ -1943,7 +1950,7 @@ getQueueMessage c rq@RcvQueue {server, rcvId, rcvPrivateKey} = do

 decryptSMPMessage :: RcvQueue -> SMP.RcvMessage -> AM SMP.ClientRcvMsgBody
 decryptSMPMessage rq SMP.RcvMessage {msgId, msgBody = SMP.EncRcvMsgBody body} =
-  liftEither $ parse SMP.clientRcvMsgBodyP (AGENT A_MESSAGE) =<< decrypt body
+  liftEither $ parse SMP.clientRcvMsgBodyP (AGENT $ A_MESSAGE "decrypt message") =<< decrypt body
  where
    decrypt = agentCbDecrypt (rcvDhSecret rq) (C.cbNonce msgId)

@@ -1982,6 +1989,28 @@ getQueueLink c nm userId server lnkId =
    getViaProxy smp proxySess = proxyGetSMPQueueLink smp nm proxySess lnkId
    getDirectly smp = getSMPQueueLink smp nm lnkId

+-- | Resolve a public-namespace name. Prefers PFWD (hides client IP from the
+-- resolver) and falls back to a direct send when the proxy is unavailable
+-- (faster but exposes the client IP). Mode selection is delegated to
+-- `sendOrProxySMPCommand`, which honours the network config (SPMNever etc.).
+resolveName :: AgentClient -> NetworkRequestMode -> UserId -> SMPServer -> SimplexDomain -> AM NameRecord
+resolveName c nm userId server domain =
+  snd <$> sendOrProxySMPCommand c nm userId server "" "RSLV" NoEntity resolveViaProxy resolveDirectly
+  where
+    resolveViaProxy smp proxySess = proxyResolveName smp nm proxySess domain
+    resolveDirectly smp = directResolveName smp nm domain
+
+-- | Pick a names-capable server for the user (the agent owns server selection,
+-- accounting for the names role). nameSrvs is opt-in (a plain list); empty means
+-- no server resolves names - a declared agent error, never a fallback.
+getNextNameServer :: AgentClient -> UserId -> AM SMPServer
+getNextNameServer c userId =
+  liftIO (TM.lookupIO userId (userServers c :: TMap UserId (UserServers 'PSMP))) >>= \case
+    Just UserServers {nameSrvs} -> case L.nonEmpty nameSrvs of
+      Just srvs -> protoServer <$> pickServer srvs
+      Nothing -> throwE NO_NAME_SERVERS
+    Nothing -> throwE $ INTERNAL "unknown userId - no user servers"
+
 enableQueueNotifications :: AgentClient -> RcvQueue -> SMP.NtfPublicAuthKey -> SMP.RcvNtfPublicDhKey -> AM (SMP.NotifierId, SMP.RcvNtfPublicDhKey)
 enableQueueNotifications c rq@RcvQueue {rcvId, rcvPrivateKey} notifierKey rcvNtfPublicDhKey =
  withSMPClient c NRMBackground rq "NKEY <nkey>" $ \smp ->
@@ -2225,8 +2254,8 @@ agentCbDecrypt dhSecret nonce msg =
 cryptoError :: C.CryptoError -> AgentErrorType
 cryptoError = \case
  C.CryptoLargeMsgError -> CMD LARGE "CryptoLargeMsgError"
-  C.CryptoHeaderError _ -> AGENT A_MESSAGE -- parsing error
-  C.CERatchetDuplicateMessage -> AGENT A_DUPLICATE
+  C.CryptoHeaderError e -> AGENT $ A_MESSAGE $ "parse msg header " <> e
+  C.CERatchetDuplicateMessage -> AGENT $ A_DUPLICATE Nothing
  C.AESDecryptError -> c DECRYPT_AES
  C.CBDecryptError -> c DECRYPT_CB
  C.CERatchetHeader -> c RATCHET_HEADER
@@ -105,12 +105,13 @@ data ServerCfg p = ServerCfg

 data ServerRoles = ServerRoles
  { storage :: Bool,
-    proxy :: Bool
+    proxy :: Bool,
+    names :: Bool
  }
  deriving (Show)

 allRoles :: ServerRoles
-allRoles = ServerRoles True True
+allRoles = ServerRoles True True True

 presetServerCfg :: Bool -> ServerRoles -> Maybe OperatorId -> ProtoServerWithAuth p -> ServerCfg p
 presetServerCfg enabled roles operator server =
@@ -119,6 +120,9 @@ presetServerCfg enabled roles operator server =
 data UserServers p = UserServers
  { storageSrvs :: NonEmpty (Maybe OperatorId, ProtoServerWithAuth p),
    proxySrvs :: NonEmpty (Maybe OperatorId, ProtoServerWithAuth p),
+    -- name resolution is opt-in: a plain list (NOT NonEmpty, no fallback-to-all).
+    -- Empty = no servers resolve names = a clean agent error, never falls back.
+    nameSrvs :: [(Maybe OperatorId, ProtoServerWithAuth p)],
    knownHosts :: Set TransportHost
  }

@@ -126,9 +130,10 @@ type OperatorId = Int64

 -- This function sets all servers as enabled in case all passed servers are disabled.
 mkUserServers :: NonEmpty (ServerCfg p) -> UserServers p
-mkUserServers srvs = UserServers {storageSrvs = filterSrvs storage, proxySrvs = filterSrvs proxy, knownHosts}
+mkUserServers srvs = UserServers {storageSrvs = filterSrvs storage, proxySrvs = filterSrvs proxy, nameSrvs, knownHosts}
  where
    filterSrvs role = L.map (\ServerCfg {operator, server} -> (operator, server)) $ fromMaybe srvs $ L.nonEmpty $ L.filter (\ServerCfg {enabled, roles} -> enabled && role roles) srvs
+    nameSrvs = map (\ServerCfg {operator, server} -> (operator, server)) $ L.filter (\ServerCfg {enabled, roles} -> enabled && names roles) srvs
    knownHosts = S.unions $ L.map (\ServerCfg {server = ProtoServerWithAuth srv _} -> serverHosts srv) srvs

 serverHosts :: ProtocolServer p -> Set TransportHost
@@ -148,6 +153,8 @@ data AgentConfig = AgentConfig
    userNetworkInterval :: Int,
    userOfflineDelay :: NominalDiffTime,
    messageTimeout :: NominalDiffTime,
+    serviceRequestTimeout :: NominalDiffTime, -- client side: default time the client waits for a service response (overridable per request)
+    serviceResponseTimeout :: NominalDiffTime, -- service side: time a received service request is valid to respond to
    connDeleteDeliveryTimeout :: NominalDiffTime,
    helloTimeout :: NominalDiffTime,
    quotaExceededTimeout :: NominalDiffTime,
@@ -165,14 +172,17 @@ data AgentConfig = AgentConfig
    xftpConsecutiveRetries :: Int,
    xftpMaxRecipientsPerRequest :: Int,
    deleteErrorCount :: Int,
+    keepAddressKeys :: Int,
    ntfCron :: Word16,
    ntfBatchSize :: Int,
    ntfSubFirstCheckInterval :: NominalDiffTime,
    ntfSubCheckInterval :: NominalDiffTime,
-    maxPendingSubscriptions :: Int,
+    subsBatchSize :: Int,
    caCertificateFile :: FilePath,
    privateKeyFile :: FilePath,
    certificateFile :: FilePath,
+    rcvExpireCount :: Int,
+    rcvExpireInterval :: NominalDiffTime,
    e2eEncryptVRange :: VersionRangeE2E,
    smpAgentVRange :: VersionRangeSMPA,
    smpClientVRange :: VersionRangeSMPC
@@ -221,6 +231,8 @@ defaultAgentConfig =
      userNetworkInterval = 1800_000000, -- 30 minutes, should be less than Int32 max value
      userOfflineDelay = 2, -- if network offline event happens in less than 2 seconds after it was set online, it is ignored
      messageTimeout = 2 * nominalDay,
+      serviceRequestTimeout = 30,
+      serviceResponseTimeout = 180,
      connDeleteDeliveryTimeout = 2 * nominalDay,
      helloTimeout = 2 * nominalDay,
      quotaExceededTimeout = 7 * nominalDay,
@@ -238,16 +250,19 @@ defaultAgentConfig =
      xftpConsecutiveRetries = 3,
      xftpMaxRecipientsPerRequest = 200,
      deleteErrorCount = 10,
+      keepAddressKeys = 3,
      ntfCron = 20, -- minutes
      ntfBatchSize = 150,
      ntfSubFirstCheckInterval = nominalDay,
      ntfSubCheckInterval = 3 * nominalDay,
-      maxPendingSubscriptions = 35000,
+      subsBatchSize = 1350,
      -- CA certificate private key is not needed for initialization
      -- ! we do not generate these
      caCertificateFile = "/etc/opt/simplex-agent/ca.crt",
      privateKeyFile = "/etc/opt/simplex-agent/agent.key",
      certificateFile = "/etc/opt/simplex-agent/agent.crt",
+      rcvExpireCount = 8,
+      rcvExpireInterval = nominalDay,
      e2eEncryptVRange = supportedE2EEncryptVRange,
      smpAgentVRange = supportedSMPAgentVRange,
      smpClientVRange = supportedSMPClientVRange
@@ -1,6 +1,7 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveAnyClass #-}
 {-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE DerivingVia #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
@@ -40,12 +41,8 @@ module Simplex.Messaging.Agent.Protocol
    VersionSMPA,
    VersionRangeSMPA,
    pattern VersionSMPA,
-    duplexHandshakeSMPAgentVersion,
-    ratchetSyncSMPAgentVersion,
-    deliveryRcptsSMPAgentVersion,
-    pqdrSMPAgentVersion,
-    sndAuthKeySMPAgentVersion,
    ratchetOnConfSMPAgentVersion,
+    rpcAddressSMPAgentVersion,
    currentSMPAgentVersion,
    supportedSMPAgentVRange,
    e2eEncConnInfoLength,
@@ -54,8 +51,10 @@ module Simplex.Messaging.Agent.Protocol
    -- * SMP agent protocol types
    ConnInfo,
    SndQueueSecured,
+    UseRatchetKeys,
    AEntityId,
    ACommand (..),
+    JoinRequest (..),
    AEvent (..),
    AEvt (..),
    ACommandTag (..),
@@ -80,6 +79,7 @@ module Simplex.Messaging.Agent.Protocol
    SMPConfirmation (..),
    AgentMsgEnvelope (..),
    AgentMessage (..),
+    RequestSignature (..),
    AgentMessageType (..),
    APrivHeader (..),
    AMessage (..),
@@ -107,6 +107,9 @@ module Simplex.Messaging.Agent.Protocol
    ConnectionModeI (..),
    ConnectionRequestUri (..),
    AConnectionRequestUri (..),
+    BinaryConnectionRequestUri (..),
+    ABinaryConnectionRequestUri (..),
+    binaryConnReq,
    ShortLinkCreds (..),
    ConnReqUriData (..),
    CRClientData,
@@ -118,10 +121,18 @@ module Simplex.Messaging.Agent.Protocol
    UserConnLinkData (..),
    UserContactData (..),
    UserLinkData (..),
+    AddressRatchetKeys,
+    NewRatchetKeys,
+    DRInvitation (..),
+    RatchetKeyId (..),
    OwnerAuth (..),
    OwnerId,
    ConnectionLink (..),
    AConnectionLink (..),
+    SimplexNameInfo (..),
+    SimplexDomain (..),
+    SimplexTLD (..),
+    SimplexNameType (..),
    ConnShortLink (..),
    AConnShortLink (..),
    CreatedConnLink (..),
@@ -133,16 +144,22 @@ module Simplex.Messaging.Agent.Protocol
    validateOwners,
    validateLinkOwners,
    sameConnReqContact,
+    sameConnShortLink,
    sameShortLinkContact,
+    sameShortLinkInv,
    simplexChat,
    connReqUriP',
    simplexConnReqUri,
    simplexShortLink,
+    fullDomainName,
+    shortNameInfoStr,
    AgentErrorType (..),
    CommandErrorType (..),
    ConnectionErrorType (..),
    BrokerErrorType (..),
    SMPAgentError (..),
+    AgentServiceError (..),
+    DroppedMsg (..),
    AgentCryptoError (..),
    cryptoErrToSyncState,
    ATransmission,
@@ -191,6 +208,7 @@ import qualified Data.Attoparsec.ByteString.Char8 as A
 import qualified Data.ByteString.Base64.URL as B64
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
+import qualified Data.ByteString.Lazy as LB
 import Data.Char (toLower, toUpper)
 import Data.Foldable (find)
 import Data.Functor (($>))
@@ -221,14 +239,17 @@ import Simplex.Messaging.Crypto.Ratchet
  ( InitialKeys (..),
    PQEncryption (..),
    PQSupport,
+    RatchetX448,
    RcvE2ERatchetParams,
    RcvE2ERatchetParamsUri,
    SndE2ERatchetParams,
+    RcvE2EPrivRatchetParams,
    pattern PQSupportOff,
    pattern PQSupportOn,
  )
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
+import Simplex.Messaging.SimplexName (SimplexDomain (..), SimplexNameInfo (..), SimplexNameType (..), SimplexTLD (..), fullDomainName, shortNameInfoStr)
 import Simplex.Messaging.Parsers
 import Simplex.Messaging.Protocol
  ( AProtocolType,
@@ -279,6 +300,7 @@ import UnliftIO.Exception (Exception)
 -- 5 - post-quantum double ratchet (3/14/2024)
 -- 6 - secure reply queues with provided keys (6/14/2024)
 -- 7 - initialize ratchet on processing confirmation (7/18/2024)
+-- 8 - agent RPC and double ratchet PQ encryption from first message to contact address (8/01/2026)

 data SMPAgentVersion

@@ -291,29 +313,20 @@ type VersionRangeSMPA = VersionRange SMPAgentVersion
 pattern VersionSMPA :: Word16 -> VersionSMPA
 pattern VersionSMPA v = Version v

-duplexHandshakeSMPAgentVersion :: VersionSMPA
-duplexHandshakeSMPAgentVersion = VersionSMPA 2
-
-ratchetSyncSMPAgentVersion :: VersionSMPA
-ratchetSyncSMPAgentVersion = VersionSMPA 3
-
-deliveryRcptsSMPAgentVersion :: VersionSMPA
-deliveryRcptsSMPAgentVersion = VersionSMPA 4
-
-pqdrSMPAgentVersion :: VersionSMPA
-pqdrSMPAgentVersion = VersionSMPA 5
-
-sndAuthKeySMPAgentVersion :: VersionSMPA
-sndAuthKeySMPAgentVersion = VersionSMPA 6
+_sndAuthKeySMPAgentVersion :: VersionSMPA
+_sndAuthKeySMPAgentVersion = VersionSMPA 6

 ratchetOnConfSMPAgentVersion :: VersionSMPA
 ratchetOnConfSMPAgentVersion = VersionSMPA 7

+rpcAddressSMPAgentVersion :: VersionSMPA
+rpcAddressSMPAgentVersion = VersionSMPA 8
+
 minSupportedSMPAgentVersion :: VersionSMPA
-minSupportedSMPAgentVersion = duplexHandshakeSMPAgentVersion
+minSupportedSMPAgentVersion = _sndAuthKeySMPAgentVersion

 currentSMPAgentVersion :: VersionSMPA
-currentSMPAgentVersion = VersionSMPA 7
+currentSMPAgentVersion = VersionSMPA 8

 supportedSMPAgentVRange :: VersionRangeSMPA
 supportedSMPAgentVRange = mkVersionRange minSupportedSMPAgentVersion currentSMPAgentVersion
@@ -321,17 +334,17 @@ supportedSMPAgentVRange = mkVersionRange minSupportedSMPAgentVersion currentSMPA
 -- it is shorter to allow all handshake headers,
 -- including E2E (double-ratchet) parameters and
 -- signing key of the sender for the server
-e2eEncConnInfoLength :: VersionSMPA -> PQSupport -> Int
-e2eEncConnInfoLength v = \case
+e2eEncConnInfoLength :: PQSupport -> Int
+e2eEncConnInfoLength = \case
  -- reduced by 3726 (roughly the increase of message ratchet header size + key and ciphertext in reply link)
-  PQSupportOn | v >= pqdrSMPAgentVersion -> 11106
-  _ -> 14832
+  PQSupportOn -> 11106
+  PQSupportOff -> 14832

-e2eEncAgentMsgLength :: VersionSMPA -> PQSupport -> Int
-e2eEncAgentMsgLength v = \case
+e2eEncAgentMsgLength :: PQSupport -> Int
+e2eEncAgentMsgLength = \case
  -- reduced by 2222 (the increase of message ratchet header size)
-  PQSupportOn | v >= pqdrSMPAgentVersion -> 13618
-  _ -> 15840
+  PQSupportOn -> 13618
+  PQSupportOff -> 15840

 -- | SMP agent event
 type ATransmission = (ACorrId, AEntityId, AEvt)
@@ -383,13 +396,18 @@ type ConnInfo = ByteString

 type SndQueueSecured = Bool

+type UseRatchetKeys = Bool
+
 -- | Parameterized type for SMP agent events
 data AEvent (e :: AEntity) where
  INV :: AConnectionRequestUri -> AEvent AEConn
  LINK :: ConnShortLink 'CMContact -> UserConnLinkData 'CMContact -> AEvent AEConn
-  LDATA :: FixedLinkData 'CMContact -> ConnLinkData 'CMContact -> AEvent AEConn
+  LDATA :: FixedLinkData 'CMContact -> ConnLinkData 'CMContact -> ConnectionRequestUri 'CMContact -> AEvent AEConn
  CONF :: ConfirmationId -> PQSupport -> [SMPServer] -> ConnInfo -> AEvent AEConn -- ConnInfo is from sender, [SMPServer] will be empty only in v1 handshake
-  REQ :: InvitationId -> PQSupport -> NonEmpty SMPServer -> ConnInfo -> AEvent AEConn -- ConnInfo is from sender
+  REQ :: InvitationId -> PQSupport -> NonEmpty SMPServer -> ConnInfo -> Bool -> AEvent AEConn -- ConnInfo is from sender; Bool - rejection reason can be sent
+  SREQ :: InvitationId -> Maybe C.PublicKeyEd25519 -> MsgBody -> AEvent AEConn
+  SSENT :: AgentMsgId -> Maybe SMPServer -> AEvent AEConn
+  RJCT :: ConnInfo -> AEvent AEConn
  INFO :: PQSupport -> ConnInfo -> AEvent AEConn
  CON :: PQEncryption -> AEvent AEConn -- notification that connection is established
  END :: AEvent AEConn
@@ -444,15 +462,15 @@ instance Eq AEvtTag where
 deriving instance Show AEvtTag

 data ACommand
-  = NEW Bool AConnectionMode InitialKeys SubscriptionMode -- response INV
+  = NEW Bool AConnectionMode InitialKeys SubscriptionMode UseRatchetKeys -- response INV
  | LSET (UserConnLinkData 'CMContact) (Maybe CRClientData) -- response LINK
  | LGET (ConnShortLink 'CMContact) -- response LDATA
-  | JOIN Bool AConnectionRequestUri PQSupport SubscriptionMode ConnInfo
+  | JOIN JoinRequest SubscriptionMode ConnInfo
  | LET ConfirmationId ConnInfo -- ConnInfo is from client
  | ACK AgentMsgId (Maybe MsgReceiptInfo)
  | SWCH
  | DEL
-  deriving (Eq, Show)
+  deriving (Show)

 data ACommandTag
  = NEW_
@@ -471,6 +489,9 @@ data AEventTag (e :: AEntity) where
  LDATA_ :: AEventTag AEConn
  CONF_ :: AEventTag AEConn
  REQ_ :: AEventTag AEConn
+  SREQ_ :: AEventTag AEConn
+  SSENT_ :: AEventTag AEConn
+  RJCT_ :: AEventTag AEConn
  INFO_ :: AEventTag AEConn
  CON_ :: AEventTag AEConn
  END_ :: AEventTag AEConn
@@ -534,6 +555,9 @@ aEventTag = \case
  LDATA {} -> LDATA_
  CONF {} -> CONF_
  REQ {} -> REQ_
+  SREQ {} -> SREQ_
+  SSENT {} -> SSENT_
+  RJCT {} -> RJCT_
  INFO {} -> INFO_
  CON _ -> CON_
  END -> END_
@@ -615,16 +639,22 @@ instance FromJSON RcvSwitchStatus where
 data SndSwitchStatus
  = SSSendingQKEY
  | SSSendingQTEST
+  | SSSecuringQueue
+  | SSSendingQEND
  deriving (Eq, Show)

 instance StrEncoding SndSwitchStatus where
  strEncode = \case
    SSSendingQKEY -> "sending_qkey"
    SSSendingQTEST -> "sending_qtest"
+    SSSecuringQueue -> "securing_queue"
+    SSSendingQEND -> "sending_qend"
  strP =
    A.takeTill (== ' ') >>= \case
      "sending_qkey" -> pure SSSendingQKEY
      "sending_qtest" -> pure SSSendingQTEST
+      "securing_queue" -> pure SSSecuringQueue
+      "sending_qend" -> pure SSSendingQEND
      _ -> fail "bad SndSwitchStatus"

 instance ToField SndSwitchStatus where toField = toField . decodeLatin1 . strEncode
@@ -798,6 +828,12 @@ data MsgMeta = MsgMeta
  }
  deriving (Eq, Show)

+data DroppedMsg = DroppedMsg
+  { brokerTs :: UTCTime,
+    attempts :: Int
+  }
+  deriving (Eq, Show)
+
 data SMPConfirmation = SMPConfirmation
  { -- | sender's public key to use for authentication of sender's commands at the recepient's server
    senderKey :: Maybe SndPublicAuthKey,
@@ -827,6 +863,12 @@ data AgentMsgEnvelope
        connReq :: ConnectionRequestUri 'CMInvitation,
        connInfo :: ByteString -- this message is only encrypted with per-queue E2E, not with double ratchet,
      }
+  | AgentContactRequest -- DR request to a contact address that published DR keys: a contact invitation or a service (RPC) request
+      { agentVersion :: VersionSMPA,
+        e2eSndParams :: SndE2ERatchetParams 'C.X448,
+        ratchetKeyId :: RatchetKeyId,
+        encConnInfo :: ByteString
+      }
  | AgentRatchetKey
      { agentVersion :: VersionSMPA,
        e2eEncryption :: RcvE2ERatchetParams 'C.X448,
@@ -842,6 +884,8 @@ instance Encoding AgentMsgEnvelope where
      smpEncode (agentVersion, 'M', Tail encAgentMessage)
    AgentInvitation {agentVersion, connReq, connInfo} ->
      smpEncode (agentVersion, 'I', Large $ strEncode connReq, Tail connInfo)
+    AgentContactRequest {agentVersion, e2eSndParams, ratchetKeyId, encConnInfo} ->
+      smpEncode (agentVersion, 'A', e2eSndParams, ratchetKeyId, Tail encConnInfo)
    AgentRatchetKey {agentVersion, e2eEncryption, info} ->
      smpEncode (agentVersion, 'R', e2eEncryption, Tail info)
  smpP = do
@@ -857,12 +901,22 @@ instance Encoding AgentMsgEnvelope where
        connReq <- strDecode . unLarge <$?> smpP
        Tail connInfo <- smpP
        pure AgentInvitation {agentVersion, connReq, connInfo}
+      'A' -> do
+        (e2eSndParams, ratchetKeyId, Tail encConnInfo) <- smpP
+        pure AgentContactRequest {agentVersion, e2eSndParams, ratchetKeyId, encConnInfo}
      'R' -> do
        e2eEncryption <- smpP
        Tail info <- smpP
        pure AgentRatchetKey {agentVersion, e2eEncryption, info}
      _ -> fail "bad AgentMsgEnvelope"

+data RequestSignature = RequestSignature C.PublicKeyEd25519 (C.Signature 'C.Ed25519)
+  deriving (Eq, Show)
+
+instance Encoding RequestSignature where
+  smpEncode (RequestSignature k sig) = smpEncode (k, sig)
+  smpP = RequestSignature <$> smpP <*> smpP
+
 -- SMP agent message formats (after double ratchet decryption,
 -- or in case of AgentInvitation - in plain text body)
 -- AgentRatchetInfo is not encrypted with double ratchet, but with per-queue E2E encryption
@@ -874,6 +928,9 @@ data AgentMessage
    AgentConnInfoReply (NonEmpty SMPQueueInfo) ConnInfo
  | AgentRatchetInfo ByteString
  | AgentMessage APrivHeader AMessage
+  | AgentServiceRequest (NonEmpty SMPQueueInfo) (Maybe RequestSignature) MsgBody
+  | AgentServiceResponse MsgBody
+  | AgentRejection ByteString
  deriving (Show)

 instance Encoding AgentMessage where
@@ -882,12 +939,18 @@ instance Encoding AgentMessage where
    AgentConnInfoReply smpQueues cInfo -> smpEncode ('D', smpQueues, Tail cInfo) -- 'D' stands for "duplex"
    AgentRatchetInfo info -> smpEncode ('R', Tail info)
    AgentMessage hdr aMsg -> smpEncode ('M', hdr, aMsg)
+    AgentServiceRequest qs sig_ body -> smpEncode ('A', qs, sig_, Tail body)
+    AgentServiceResponse body -> smpEncode ('P', Tail body)
+    AgentRejection reason -> smpEncode ('J', Tail reason)
  smpP =
    smpP >>= \case
      'I' -> AgentConnInfo . unTail <$> smpP
      'D' -> AgentConnInfoReply <$> smpP <*> (unTail <$> smpP)
      'R' -> AgentRatchetInfo . unTail <$> smpP
      'M' -> AgentMessage <$> smpP <*> smpP
+      'A' -> AgentServiceRequest <$> smpP <*> smpP <*> (unTail <$> smpP)
+      'P' -> AgentServiceResponse . unTail <$> smpP
+      'J' -> AgentRejection . unTail <$> smpP
      _ -> fail "bad AgentMessage"

 -- internal type for storing message type in the database
@@ -903,7 +966,11 @@ data AgentMessageType
  | AM_QKEY_
  | AM_QUSE_
  | AM_QTEST_
+  | AM_QEND_
  | AM_EREADY_
+  | AM_SRV_REQ
+  | AM_SRV_RESP
+  | AM_RJCT
  deriving (Eq, Show)

 instance Encoding AgentMessageType where
@@ -919,7 +986,11 @@ instance Encoding AgentMessageType where
    AM_QKEY_ -> "QK"
    AM_QUSE_ -> "QU"
    AM_QTEST_ -> "QT"
+    AM_QEND_ -> "QE"
    AM_EREADY_ -> "E"
+    AM_SRV_REQ -> "A"
+    AM_SRV_RESP -> "P"
+    AM_RJCT -> "J"
  smpP =
    A.anyChar >>= \case
      'C' -> pure AM_CONN_INFO
@@ -935,8 +1006,12 @@ instance Encoding AgentMessageType where
          'K' -> pure AM_QKEY_
          'U' -> pure AM_QUSE_
          'T' -> pure AM_QTEST_
+          'E' -> pure AM_QEND_
          _ -> fail "bad AgentMessageType"
      'E' -> pure AM_EREADY_
+      'A' -> pure AM_SRV_REQ
+      'P' -> pure AM_SRV_RESP
+      'J' -> pure AM_RJCT
      _ -> fail "bad AgentMessageType"

 agentMessageType :: AgentMessage -> AgentMessageType
@@ -945,6 +1020,9 @@ agentMessageType = \case
  AgentConnInfoReply {} -> AM_CONN_INFO_REPLY
  AgentRatchetInfo _ -> AM_RATCHET_INFO
  AgentMessage _ aMsg -> aMessageType aMsg
+  AgentServiceRequest {} -> AM_SRV_REQ
+  AgentServiceResponse {} -> AM_SRV_RESP
+  AgentRejection {} -> AM_RJCT

 data APrivHeader = APrivHeader
  { -- | sequential ID assigned by the sending agent
@@ -968,6 +1046,7 @@ data AMsgType
  | QKEY_
  | QUSE_
  | QTEST_
+  | QEND_
  | EREADY_
  deriving (Eq)

@@ -981,6 +1060,7 @@ instance Encoding AMsgType where
    QKEY_ -> "QK"
    QUSE_ -> "QU"
    QTEST_ -> "QT"
+    QEND_ -> "QE"
    EREADY_ -> "E"
  smpP =
    A.anyChar >>= \case
@@ -994,6 +1074,7 @@ instance Encoding AMsgType where
          'K' -> pure QKEY_
          'U' -> pure QUSE_
          'T' -> pure QTEST_
+          'E' -> pure QEND_
          _ -> fail "bad AMsgType"
      'E' -> pure EREADY_
      _ -> fail "bad AMsgType"
@@ -1018,6 +1099,8 @@ data AMessage
    QUSE (NonEmpty (SndQAddr, Bool))
  | -- sent by the sender to test new queues and to complete switching
    QTEST (NonEmpty SndQAddr)
+  | -- sent by the sender to remove queues from the connection (fast rotation, v8)
+    QEND (NonEmpty SndQAddr)
  | -- ratchet re-synchronization is complete, with last decrypted sender message id (recipient's `last_external_snd_msg_id`)
    EREADY AgentMsgId
  deriving (Show)
@@ -1036,6 +1119,7 @@ aMessageType = \case
  QKEY _ -> AM_QKEY_
  QUSE _ -> AM_QUSE_
  QTEST _ -> AM_QTEST_
+  QEND _ -> AM_QEND_
  EREADY _ -> AM_EREADY_

 -- | this type is used to send as part of the protocol between different clients
@@ -1088,6 +1172,7 @@ instance Encoding AMessage where
    QKEY qs -> smpEncode (QKEY_, qs)
    QUSE qs -> smpEncode (QUSE_, qs)
    QTEST qs -> smpEncode (QTEST_, qs)
+    QEND qs -> smpEncode (QEND_, qs)
    EREADY lastDecryptedMsgId -> smpEncode (EREADY_, lastDecryptedMsgId)
  smpP =
    smpP
@@ -1100,6 +1185,7 @@ instance Encoding AMessage where
        QKEY_ -> QKEY <$> smpP
        QUSE_ -> QUSE <$> smpP
        QTEST_ -> QTEST <$> smpP
+        QEND_ -> QEND <$> smpP
        EREADY_ -> EREADY <$> smpP

 instance ToField AMessage where toField = toField . Binary . smpEncode
@@ -1115,11 +1201,13 @@ instance Encoding AMessageReceipt where

 instance ConnectionModeI m => StrEncoding (ConnectionRequestUri m) where
  strEncode = \case
-    CRInvitationUri crData e2eParams -> crEncode "invitation" crData (Just e2eParams)
-    CRContactUri crData -> crEncode "contact" crData Nothing
+    CRInvitationUri crData e2eParams -> crEncode "invitation" crData (Just e2eParams, Nothing)
+    CRContactUri crData rks -> crEncode "contact" crData $ case rks of
+      Just (ratchetKeyId, e2eRcvParams) -> (Just e2eRcvParams, Just ratchetKeyId)
+      Nothing -> (Nothing, Nothing)
    where
-      crEncode :: ByteString -> ConnReqUriData -> Maybe (RcvE2ERatchetParamsUri 'C.X448) -> ByteString
-      crEncode crMode ConnReqUriData {crScheme, crAgentVRange, crSmpQueues, crClientData} e2eParams =
+      crEncode :: ByteString -> ConnReqUriData -> (Maybe (RcvE2ERatchetParamsUri 'C.X448), Maybe RatchetKeyId) -> ByteString
+      crEncode crMode ConnReqUriData {crScheme, crAgentVRange, crSmpQueues, crClientData} (e2eParams, rk) =
        strEncode crScheme <> "/" <> crMode <> "#/?" <> queryStr
        where
          queryStr =
@@ -1127,23 +1215,24 @@ instance ConnectionModeI m => StrEncoding (ConnectionRequestUri m) where
              -- semicolon is used to separate SMP queues because comma is used to separate server address hostnames
              [("v", strEncode crAgentVRange), ("smp", B.intercalate ";" $ map strEncode $ L.toList crSmpQueues)]
                <> maybe [] (\e2e -> [("e2e", strEncode e2e)]) e2eParams
+                <> maybe [] (\k -> [("rk", strEncode k)]) rk
                <> maybe [] (\cd -> [("data", encodeUtf8 cd)]) crClientData
  strP = connReqUriP' (Just SSSimplex)

-instance ConnectionModeI m => Encoding (ConnectionRequestUri m) where
+instance ConnectionModeI m => Encoding (BinaryConnectionRequestUri m) where
  smpEncode = \case
-    CRInvitationUri crData e2eParams -> smpEncode (CMInvitation, crData, e2eParams)
-    CRContactUri crData -> smpEncode (CMContact, crData)
-  smpP = (\(ACR _ cr) -> checkConnMode cr) <$?> smpP
+    BCRInvitationUri crData e2eParams -> smpEncode (CMInvitation, crData, e2eParams)
+    BCRContactUri crData -> smpEncode (CMContact, crData)
+  smpP = (\(ABCR _ cr) -> checkConnMode cr) <$?> smpP
  {-# INLINE smpP #-}

-instance Encoding AConnectionRequestUri where
-  smpEncode (ACR _ cr) = smpEncode cr
+instance Encoding ABinaryConnectionRequestUri where
+  smpEncode (ABCR _ cr) = smpEncode cr
  {-# INLINE smpEncode #-}
  smpP =
    smpP >>= \case
-      CMInvitation -> ACR SCMInvitation <$> (CRInvitationUri <$> smpP <*> smpP)
-      CMContact -> ACR SCMContact . CRContactUri <$> smpP
+      CMInvitation -> ABCR SCMInvitation <$> (BCRInvitationUri <$> smpP <*> smpP)
+      CMContact -> ABCR SCMContact . BCRContactUri <$> smpP

 instance Encoding ConnReqUriData where
  smpEncode ConnReqUriData {crAgentVRange, crSmpQueues, crClientData} =
@@ -1186,7 +1275,10 @@ connReqUriP overrideScheme = do
      pure . ACR SCMInvitation $ CRInvitationUri crData crE2eParams
    -- contact links are adjusted to the minimum version supported by the agent
    -- to preserve compatibility with the old links published online
-    CMContact -> pure . ACR SCMContact $ CRContactUri crData {crAgentVRange = adjustAgentVRange aVRange}
+    CMContact -> do
+      e2e_ <- queryParam_ "e2e" query
+      rk_ <- queryParam_ "rk" query
+      pure . ACR SCMContact $ CRContactUri crData {crAgentVRange = adjustAgentVRange aVRange} ((,) <$> rk_ <*> e2e_)
  where
    crModeP = "invitation" $> CMInvitation <|> "contact" $> CMContact
    -- semicolon is used to separate SMP queues because comma is used to separate server address hostnames
@@ -1312,6 +1404,7 @@ sameQueue addr q = sameQAddress addr (qAddress q)

 data SMPQueueInfo = SMPQueueInfo {clientVersion :: VersionSMPC, queueAddress :: SMPQueueAddress}
  deriving (Eq, Show)
+  deriving (ToJSON, FromJSON) via (StrJSON "SMPQueueInfo" SMPQueueInfo)

 instance Encoding SMPQueueInfo where
  smpEncode (SMPQueueInfo clientVersion SMPQueueAddress {smpServer, senderId, dhPublicKey, queueMode})
@@ -1417,6 +1510,10 @@ instance StrEncoding SMPQueueUri where
              _ -> Nothing
        pure (vr, maybe [] thList_ hs_, dhKey, queueMode)

+instance StrEncoding SMPQueueInfo where
+  strEncode (SMPQueueInfo v addr) = strEncode (SMPQueueUri (versionToRange v) addr)
+  strP = (\(SMPQueueUri vr addr) -> SMPQueueInfo (maxVersion vr) addr) <$> strP
+
 instance Encoding SMPQueueUri where
  smpEncode (SMPQueueUri clientVRange@(VersionRange minV maxV) SMPQueueAddress {smpServer, senderId, dhPublicKey, queueMode})
    -- The condition is for minVersion as earlier clients won't be able to support it.
@@ -1436,16 +1533,30 @@ instance Encoding SMPQueueUri where
 queueModeP :: Parser (Maybe QueueMode)
 queueModeP = Just <$> smpP <|> optional ((\case True -> QMMessaging; _ -> QMContact) <$> smpP)

+data BinaryConnectionRequestUri (m :: ConnectionMode) where
+  BCRInvitationUri :: ConnReqUriData -> RcvE2ERatchetParamsUri 'C.X448 -> BinaryConnectionRequestUri CMInvitation
+  BCRContactUri :: ConnReqUriData -> BinaryConnectionRequestUri CMContact
+
+deriving instance Eq (BinaryConnectionRequestUri m)
+
+deriving instance Show (BinaryConnectionRequestUri m)
+
+data ABinaryConnectionRequestUri = forall m. ConnectionModeI m => ABCR (SConnectionMode m) (BinaryConnectionRequestUri m)
+
 data ConnectionRequestUri (m :: ConnectionMode) where
  CRInvitationUri :: ConnReqUriData -> RcvE2ERatchetParamsUri 'C.X448 -> ConnectionRequestUri CMInvitation
-  -- contact connection request does NOT contain E2E encryption parameters for double ratchet -
-  -- they are passed in AgentInvitation message
-  CRContactUri :: ConnReqUriData -> ConnectionRequestUri CMContact
+  -- optional contact address DR keys for double ratchet e2e from message 1
+  CRContactUri :: ConnReqUriData -> Maybe AddressRatchetKeys -> ConnectionRequestUri CMContact

 simplexConnReqUri :: ConnectionRequestUri m -> ConnectionRequestUri m
 simplexConnReqUri = \case
  CRInvitationUri crData e2eParams -> CRInvitationUri crData {crScheme = SSSimplex} e2eParams
-  CRContactUri crData -> CRContactUri crData {crScheme = SSSimplex}
+  CRContactUri crData rk -> CRContactUri crData {crScheme = SSSimplex} rk
+
+binaryConnReq :: ConnectionRequestUri m -> BinaryConnectionRequestUri m
+binaryConnReq = \case
+  CRInvitationUri crData e2eParams -> BCRInvitationUri crData e2eParams
+  CRContactUri crData _ -> BCRContactUri crData

 deriving instance Eq (ConnectionRequestUri m)

@@ -1503,9 +1614,12 @@ data PreparedLinkParams = PreparedLinkParams
    -- | smpEncode of FixedLinkData (includes linkEntityId)
    plpSignedFixedData :: ByteString,
    -- | Server with basic auth (not stored in link)
-    plpSrvWithAuth :: SMPServerWithAuth
+    plpSrvWithAuth :: SMPServerWithAuth,
+    -- | Initial PQ keys
+    plpInitKeys :: InitialKeys,
+    -- | Contact address double ratchet keys
+    plpAddressKeys :: Maybe (RatchetKeyId, RcvE2EPrivRatchetParams 'C.X448)
  }
-  deriving (Show)

 instance ConnectionModeI c => ToField (ConnectionLink c) where toField = toField . Binary . strEncode

@@ -1675,6 +1789,10 @@ ctTypeChar = \case
  CCTRelay -> 'R'
 {-# INLINE ctTypeChar #-}

+instance StrEncoding ContactConnType where
+  strEncode = B.singleton . ctTypeChar
+  strP = A.anyChar >>= ctTypeP
+
 -- the servers passed to this function should be all preset servers, not servers configured by the user.
 shortenShortLink :: NonEmpty SMPServer -> ConnShortLink m -> ConnShortLink m
 shortenShortLink presetSrvs = \case
@@ -1713,15 +1831,26 @@ findPresetServer ProtocolServer {host = h :| _} = find (\ProtocolServer {host =
 {-# INLINE findPresetServer #-}

 sameConnReqContact :: ConnectionRequestUri 'CMContact -> ConnectionRequestUri 'CMContact -> Bool
-sameConnReqContact (CRContactUri ConnReqUriData {crSmpQueues = qs}) (CRContactUri ConnReqUriData {crSmpQueues = qs'}) =
+sameConnReqContact (CRContactUri ConnReqUriData {crSmpQueues = qs} _) (CRContactUri ConnReqUriData {crSmpQueues = qs'} _) =
  L.length qs == L.length qs' && all same (L.zip qs qs')
  where
    same (q, q') = sameQAddress (qAddress q) (qAddress q')

+sameConnShortLink :: AConnShortLink -> AConnShortLink -> Bool
+sameConnShortLink (ACSL m sl) (ACSL m' sl') = case testEquality m m' of
+  Just Refl -> case sl of
+    CSLContact {} -> sameShortLinkContact sl sl'
+    CSLInvitation {} -> sameShortLinkInv sl sl'
+  Nothing -> False
+
 sameShortLinkContact :: ConnShortLink 'CMContact -> ConnShortLink 'CMContact -> Bool
 sameShortLinkContact (CSLContact _ ct srv k) (CSLContact _ ct' srv' k') =
  ct == ct' && sameSrvAddr srv srv' && k == k'

+sameShortLinkInv :: ConnShortLink 'CMInvitation -> ConnShortLink 'CMInvitation -> Bool
+sameShortLinkInv (CSLInvitation _ srv lnkId k) (CSLInvitation _ srv' lnkId' k') =
+  sameSrvAddr srv srv' && lnkId == lnkId' && k == k'
+
 checkConnMode :: forall t m m'. (ConnectionModeI m, ConnectionModeI m') => t m' -> Either String (t m)
 checkConnMode c = case testEquality (sConnectionMode @m) (sConnectionMode @m') of
  Just Refl -> Right c
@@ -1741,7 +1870,7 @@ type CRClientData = Text
 data FixedLinkData c = FixedLinkData
  { agentVRange :: VersionRangeSMPA,
    rootKey :: C.PublicKeyEd25519,
-    linkConnReq :: ConnectionRequestUri c,
+    linkConnReq :: BinaryConnectionRequestUri c,
    linkEntityId :: Maybe ByteString
  }
  deriving (Eq, Show)
@@ -1754,6 +1883,31 @@ deriving instance Eq (ConnLinkData c)

 deriving instance Show (ConnLinkData c)

+newtype RatchetKeyId = RatchetKeyId ByteString
+  deriving (Eq, Show)
+  deriving newtype (Encoding, StrEncoding)
+
+-- | double ratchet keys in contact address
+type AddressRatchetKeys = (RatchetKeyId, RcvE2ERatchetParamsUri 'C.X448)
+
+-- | Whether to rotate double ratchet keys in contact address
+type NewRatchetKeys = Bool
+
+-- | stored invitation with double ratchet keys
+data DRInvitation = DRInvitation
+  { ratchetState :: RatchetX448,
+    replyQueue :: SMPQueueInfo,
+    agentVersion :: VersionSMPA,
+    pqSupport :: PQSupport
+  }
+  deriving (Show)
+
+data JoinRequest
+  = JRConnReq {enableNtfs :: Bool, joinConnReq :: AConnectionRequestUri, joinPQSupport :: PQSupport}
+  | JRServiceReq {contactReq :: ConnectionRequestUri 'CMContact, joinPQSupport :: PQSupport, requestKey :: Maybe (C.StoredPrivateKey C.Ed25519)}
+  | JRInvitationDR DRInvitation
+  deriving (Show)
+
 data UserContactData = UserContactData
  { -- direct connection via connReq in fixed data is allowed.
    direct :: Bool,
@@ -1761,7 +1915,8 @@ data UserContactData = UserContactData
    owners :: [OwnerAuth],
    -- alternative addresses of chat relays that receive requests for this contact address.
    relays :: [ConnShortLink 'CMContact],
-    userData :: UserLinkData
+    userData :: UserLinkData,
+    ratchetKeys :: Maybe AddressRatchetKeys
  }
  deriving (Eq, Show)

@@ -1839,10 +1994,12 @@ validateLinkOwners rootKey = go []

 instance ConnectionModeI c => Encoding (FixedLinkData c) where
  smpEncode FixedLinkData {agentVRange, rootKey, linkConnReq, linkEntityId} =
+    -- TODO this encoding is not extensible, replace with smpEncode (fromMaybe "" linkEntityId) - safe to do it in 2027
    smpEncode (agentVRange, rootKey, linkConnReq) <> maybe "" smpEncode linkEntityId
  smpP = do
    (agentVRange, rootKey, linkConnReq) <- smpP
-    linkEntityId <- optional smpP <* A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
+    linkEntityId <- ((\s -> if B.null s then Nothing else Just s) =<<) <$> optional smpP
+    _ <- A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding (added in January 2026)
    pure FixedLinkData {agentVRange, rootKey, linkConnReq, linkEntityId}

 instance ConnectionModeI c => Encoding (ConnLinkData c) where
@@ -1889,14 +2046,13 @@ instance ConnectionModeI c => StrEncoding (UserConnLinkData c) where
  {-# INLINE strP #-}

 instance Encoding UserContactData where
-  smpEncode UserContactData {direct, owners, relays, userData} =
-    B.concat [smpEncode direct, smpEncodeList owners, smpEncodeList relays, smpEncode userData]
+  smpEncode UserContactData {direct, owners, relays, userData, ratchetKeys} =
+    smpEncode (direct, EncList owners, EncList relays, userData, ratchetKeys)
  smpP = do
-    direct <- smpP
-    owners <- smpListP
-    relays <- smpListP
-    userData <- smpP <* A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
-    pure UserContactData {direct, owners, relays, userData}
+    (direct, EncList owners, EncList relays, userData) <- smpP
+    ratchetKeys <- smpP <|> pure Nothing
+    _ <- A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
+    pure UserContactData {direct, owners, relays, userData, ratchetKeys}

 instance Encoding UserLinkData where
  smpEncode (UserLinkData s) = if B.length s <= 254 then smpEncode s else smpEncode ('\255', Large s)
@@ -1984,6 +2140,9 @@ data AgentErrorType
    XFTP {serverAddress :: String, xftpErr :: XFTPErrorType}
  | -- | XFTP agent errors
    FILE {fileErr :: FileErrorType}
+  | -- | no name-resolving servers configured for the user (agent-origin).
+    -- Server-origin name errors arrive forwarded as SMP _ (NAME ...) instead.
+    NO_NAME_SERVERS
  | -- | SMP proxy errors
    PROXY {proxyServer :: String, relayServer :: String, proxyErr :: ProxyClientError}
  | -- | XRCP protocol errors forwarded to agent clients
@@ -2041,7 +2200,7 @@ data ConnectionErrorType
 -- | Errors of another SMP agent.
 data SMPAgentError
  = -- | client or agent message that failed to parse
-    A_MESSAGE
+    A_MESSAGE {messageErr :: String}
  | -- | prohibited SMP/agent message
    A_PROHIBITED {prohibitedErr :: String}
  | -- | incompatible version of SMP client, agent or encryption protocols
@@ -2050,12 +2209,22 @@ data SMPAgentError
    A_LINK {linkErr :: String}
  | -- | cannot decrypt message
    A_CRYPTO {cryptoErr :: AgentCryptoError}
-  | -- | duplicate message - this error is detected by ratchet decryption - this message will be ignored and not shown
-    -- it may also indicate a loss of ratchet synchronization (when only one message is sent via copied ratchet)
-    A_DUPLICATE
+  | -- | duplicate message - this error is detected by ratchet decryption - this message will be ignored and not shown.
+    -- it may also indicate a loss of ratchet synchronization (when only one message is sent via copied ratchet).
+    -- when message is dropped after too many reception attempts, DroppedMsg is included.
+    A_DUPLICATE {droppedMsg_ :: Maybe DroppedMsg}
  | -- | error in the message to add/delete/etc queue in connection
    A_QUEUE {queueErr :: String}
-  deriving (Eq, Read, Show, Exception)
+  | A_SERVICE {serviceError :: AgentServiceError}
+  deriving (Eq, Show, Exception)
+
+data AgentServiceError
+  = ASERejected {rejectReason :: Text}
+  | ASETimeout
+  | ASENoPendingRequest
+  | ASENotDRAddress
+  | ASEBadSignature
+  deriving (Eq, Show)

 data AgentCryptoError
  = -- | AES decryption error
@@ -2081,6 +2250,19 @@ cryptoErrToSyncState = \case
  RATCHET_SKIPPED _ -> RSRequired
  RATCHET_SYNC -> RSRequired

+$(J.deriveJSON defaultJSON ''DRInvitation)
+
+-- JRConnReq is identical to JOIN before DR support for old/new client compatibility
+instance StrEncoding JoinRequest where
+  strEncode = \case
+    JRConnReq ntfs cReq pqSup -> strEncode (ntfs, cReq, pqSup)
+    JRServiceReq cReq pqSup signKey -> strEncode ('S', cReq, pqSup, signKey)
+    JRInvitationDR dr -> serializeBinary $ LB.toStrict (J'.encode dr)
+  strP =
+    (A.char 'S' *> (JRServiceReq <$> _strP <*> _strP <*> _strP))
+      <|> (JRConnReq <$> strP <*> _strP <*> (_strP <|> pure PQSupportOff))
+      <|> (JRInvitationDR <$> (J'.eitherDecodeStrict' <$?> (A.take =<< (A.decimal <* "\n"))))
+
 -- | SMP agent command and response parser for commands stored in db (fully parses binary bodies)
 dbCommandP :: Parser ACommand
 dbCommandP = commandP $ A.take =<< (A.decimal <* "\n")
@@ -2111,10 +2293,11 @@ commandP :: Parser ByteString -> Parser ACommand
 commandP binaryP =
  strP
    >>= \case
-      NEW_ -> s (NEW <$> strP_ <*> strP_ <*> pqIKP <*> (strP <|> pure SMP.SMSubscribe))
+      -- useDR is a trailing field defaulting to False, so NEW persisted before it was added still parses
+      NEW_ -> s (NEW <$> strP_ <*> strP_ <*> pqIKP <*> (strP <|> pure SMP.SMSubscribe) <*> (_strP <|> pure False))
      LSET_ -> s (LSET <$> strP <*> optional (A.space *> strP))
      LGET_ -> s (LGET <$> strP)
-      JOIN_ -> s (JOIN <$> strP_ <*> strP_ <*> pqSupP <*> (strP_ <|> pure SMP.SMSubscribe) <*> binaryP)
+      JOIN_ -> s (JOIN <$> strP_ <*> (strP_ <|> pure SMP.SMSubscribe) <*> binaryP)
      LET_ -> s (LET <$> A.takeTill (== ' ') <* A.space <*> binaryP)
      ACK_ -> s (ACK <$> A.decimal <*> optional (A.space *> binaryP))
      SWCH_ -> pure SWCH
@@ -2124,16 +2307,14 @@ commandP binaryP =
    s p = A.space *> p
    pqIKP :: Parser InitialKeys
    pqIKP = strP_ <|> pure (IKLinkPQ PQSupportOff)
-    pqSupP :: Parser PQSupport
-    pqSupP = strP_ <|> pure PQSupportOff

 -- | Serialize SMP agent command.
 serializeCommand :: ACommand -> ByteString
 serializeCommand = \case
-  NEW ntfs cMode pqIK subMode -> s (NEW_, ntfs, cMode, pqIK, subMode)
+  NEW ntfs cMode pqIK subMode useDR -> s (NEW_, ntfs, cMode, pqIK, subMode, useDR)
  LSET uld cd_ -> s (LSET_, uld) <> maybe "" (B.cons ' ' . s) cd_
  LGET sl -> s (LGET_, sl)
-  JOIN ntfs cReq pqSup subMode cInfo -> s (JOIN_, ntfs, cReq, pqSup, subMode, Str $ serializeBinary cInfo)
+  JOIN joinReq subMode cInfo -> s (JOIN_, joinReq, subMode, Str $ serializeBinary cInfo)
  LET confId cInfo -> B.unwords [s LET_, confId, serializeBinary cInfo]
  ACK mId rcptInfo_ -> s (ACK_, mId) <> maybe "" (B.cons ' ' . serializeBinary) rcptInfo_
  SWCH -> s SWCH_
@@ -2165,6 +2346,10 @@ $(J.deriveJSON (sumTypeJSON id) ''ConnectionErrorType)

 $(J.deriveJSON (sumTypeJSON id) ''AgentCryptoError)

+$(J.deriveJSON (sumTypeJSON $ dropPrefix "ASE") ''AgentServiceError)
+
+$(J.deriveJSON defaultJSON ''DroppedMsg)
+
 $(J.deriveJSON (sumTypeJSON id) ''SMPAgentError)

 $(J.deriveJSON (sumTypeJSON id) ''AgentErrorType)
@@ -2191,3 +2376,4 @@ instance FromJSON ACreatedConnLink where
 instance ToJSON ACreatedConnLink where
  toEncoding (ACCL _ ccLink) = toEncoding ccLink
  toJSON (ACCL _ ccLink) = toJSON ccLink
+
@@ -45,6 +45,8 @@ module Simplex.Messaging.Agent.Store
    AcceptedConfirmation (..),
    NewInvitation (..),
    Invitation (..),
+    ContactRequest (..),
+    DRInvitation (..),
    PrevExternalSndId,
    PrevRcvMsgHash,
    PrevSndMsgHash,
@@ -205,12 +207,13 @@ rcvSMPQueueAddress :: RcvQueue -> SMPQueueAddress
 rcvSMPQueueAddress RcvQueue {server, sndId, e2ePrivKey, queueMode} =
  SMPQueueAddress server sndId (C.publicKey e2ePrivKey) queueMode

-canAbortRcvSwitch :: RcvQueue -> Bool
-canAbortRcvSwitch = maybe False canAbort . rcvSwchStatus
+canAbortRcvSwitch :: ConnData -> RcvQueue -> Bool
+canAbortRcvSwitch ConnData {connAgentVersion} = maybe False canAbort . rcvSwchStatus
  where
    canAbort = \case
      RSSwitchStarted -> True
-      RSSendingQADD -> True
+      -- at agent version 8 and above the peer always chooses fast rotation, so a sent QADD is committed
+      RSSendingQADD -> connAgentVersion < rpcAddressSMPAgentVersion
      -- if switch is in RSSendingQUSE, a race condition with sender deleting the original queue is possible
      RSSendingQUSE -> False
      -- if switch is in RSReceivedMessage status, aborting switch (deleting new queue)
@@ -463,7 +466,9 @@ data ConnData = ConnData
    lastExternalSndId :: PrevExternalSndId,
    deleted :: Bool,
    ratchetSyncState :: RatchetSyncState,
-    pqSupport :: PQSupport
+    pqSupport :: PQSupport,
+    -- client side: set on the requester's connection for a service request; Nothing otherwise. The time the client stops waiting for the response (created + serviceRequestTimeout or per-call override).
+    serviceRequestExpiresAt :: Maybe UTCTime
  }
  deriving (Eq, Show)

@@ -471,8 +476,8 @@ type NoticeId = Int64

 -- this function should be mirrored in the clients
 ratchetSyncAllowed :: ConnData -> Bool
-ratchetSyncAllowed ConnData {ratchetSyncState, connAgentVersion} =
-  connAgentVersion >= ratchetSyncSMPAgentVersion && (ratchetSyncState `elem` ([RSAllowed, RSRequired] :: [RatchetSyncState]))
+ratchetSyncAllowed ConnData {ratchetSyncState} =
+  ratchetSyncState `elem` ([RSAllowed, RSRequired] :: [RatchetSyncState])

 -- this function should be mirrored in the clients
 ratchetSyncSendProhibited :: ConnData -> Bool
@@ -534,7 +539,9 @@ data InternalCommand
  | ICDeleteConn
  | ICDeleteRcvQueue SMP.RecipientId
  | ICQSecure SMP.RecipientId SMP.SndPublicAuthKey
+  | ICQSndSecure SMP.SenderId
  | ICQDelete SMP.RecipientId
+  | ICReplyDel

 data InternalCommandTag
  = ICAck_
@@ -544,7 +551,9 @@ data InternalCommandTag
  | ICDeleteConn_
  | ICDeleteRcvQueue_
  | ICQSecure_
+  | ICQSndSecure_
  | ICQDelete_
+  | ICReplyDel_
  deriving (Show)

 instance StrEncoding InternalCommand where
@@ -556,7 +565,9 @@ instance StrEncoding InternalCommand where
    ICDeleteConn -> strEncode ICDeleteConn_
    ICDeleteRcvQueue rId -> strEncode (ICDeleteRcvQueue_, rId)
    ICQSecure rId senderKey -> strEncode (ICQSecure_, rId, senderKey)
+    ICQSndSecure sId -> strEncode (ICQSndSecure_, sId)
    ICQDelete rId -> strEncode (ICQDelete_, rId)
+    ICReplyDel -> strEncode ICReplyDel_
  strP =
    strP >>= \case
      ICAck_ -> ICAck <$> _strP <*> _strP
@@ -566,7 +577,9 @@ instance StrEncoding InternalCommand where
      ICDeleteConn_ -> pure ICDeleteConn
      ICDeleteRcvQueue_ -> ICDeleteRcvQueue <$> _strP
      ICQSecure_ -> ICQSecure <$> _strP <*> _strP
+      ICQSndSecure_ -> ICQSndSecure <$> _strP
      ICQDelete_ -> ICQDelete <$> _strP
+      ICReplyDel_ -> pure ICReplyDel

 instance StrEncoding InternalCommandTag where
  strEncode = \case
@@ -577,7 +590,9 @@ instance StrEncoding InternalCommandTag where
    ICDeleteConn_ -> "DELETE_CONN"
    ICDeleteRcvQueue_ -> "DELETE_RCV_QUEUE"
    ICQSecure_ -> "QSECURE"
+    ICQSndSecure_ -> "QSND_SECURE"
    ICQDelete_ -> "QDELETE"
+    ICReplyDel_ -> "REPLY_DEL"
  strP =
    A.takeTill (== ' ') >>= \case
      "ACK" -> pure ICAck_
@@ -587,7 +602,9 @@ instance StrEncoding InternalCommandTag where
      "DELETE_CONN" -> pure ICDeleteConn_
      "DELETE_RCV_QUEUE" -> pure ICDeleteRcvQueue_
      "QSECURE" -> pure ICQSecure_
+      "QSND_SECURE" -> pure ICQSndSecure_
      "QDELETE" -> pure ICQDelete_
+      "REPLY_DEL" -> pure ICReplyDel_
      _ -> fail "bad InternalCommandTag"

 agentCommandTag :: AgentCommand -> AgentCommandTag
@@ -604,7 +621,9 @@ internalCmdTag = \case
  ICDeleteConn -> ICDeleteConn_
  ICDeleteRcvQueue {} -> ICDeleteRcvQueue_
  ICQSecure {} -> ICQSecure_
+  ICQSndSecure {} -> ICQSndSecure_
  ICQDelete _ -> ICQDelete_
+  ICReplyDel -> ICReplyDel_

 -- * Confirmation types

@@ -626,19 +645,28 @@ data AcceptedConfirmation = AcceptedConfirmation

 data NewInvitation = NewInvitation
  { contactConnId :: ConnId,
-    connReq :: ConnectionRequestUri 'CMInvitation,
-    recipientConnInfo :: ConnInfo
+    connReq :: ContactRequest,
+    recipientConnInfo :: ConnInfo,
+    -- service side: the received request is a service request (SREQ) not a contact request (REQ)
+    serviceRequest :: Bool
  }

 data Invitation = Invitation
  { invitationId :: InvitationId,
    contactConnId_ :: Maybe ConnId,
-    connReq :: ConnectionRequestUri 'CMInvitation,
+    connReq :: ContactRequest,
    recipientConnInfo :: ConnInfo,
    ownConnInfo :: Maybe ConnInfo,
-    accepted :: Bool
+    accepted :: Bool,
+    -- service side: the received request is a service request (SREQ) not a contact request (REQ)
+    serviceRequest :: Bool,
+    createdAt :: UTCTime
  }

+data ContactRequest
+  = CRInvitation (ConnectionRequestUri 'CMInvitation)
+  | CRInvitationDR DRInvitation
+
 -- * Message integrity validation types

 -- | Corresponds to `last_external_snd_msg_id` in `connections` table
@@ -73,6 +73,8 @@ module Simplex.Messaging.Agent.Store.AgentStore
    setConnPQSupport,
    updateNewConnJoin,
    getDeletedConnIds,
+    getExpiredServiceConns,
+    deleteExpiredServiceRequests,
    getDeletedWaitingDeliveryConnIds,
    setConnRatchetSync,
    addProcessedRatchetKeyHash,
@@ -129,6 +131,8 @@ module Simplex.Messaging.Agent.Store.AgentStore
    createSndMsg,
    updateSndMsgHash,
    createSndMsgDelivery,
+    copyPendingSndDeliveries,
+    countSndQueueDeliveries,
    getSndMsgViaRcpt,
    updateSndMsgRcpt,
    getPendingQueueMsg,
@@ -140,6 +144,7 @@ module Simplex.Messaging.Agent.Store.AgentStore
    setMsgUserAck,
    getRcvMsg,
    getLastMsg,
+    incMsgRcvAttempts,
    checkRcvMsgHashExists,
    getRcvMsgBrokerTs,
    deleteMsg,
@@ -151,6 +156,10 @@ module Simplex.Messaging.Agent.Store.AgentStore
    createRatchetX3dhKeys,
    getRatchetX3dhKeys,
    setRatchetX3dhKeys,
+    createAddressRatchetKeys,
+    getCurrentAddressRatchetKeys,
+    getAddressRatchetKeys,
+    deleteOldAddressRatchetKeys,
    createSndRatchet,
    getSndRatchet,
    createRatchet,
@@ -277,9 +286,11 @@ import Control.Monad.IO.Class
 import Control.Monad.Trans.Except
 import Crypto.Random (ChaChaDRG)
 import Data.Bifunctor (first)
+import qualified Data.Aeson as J
 import Data.ByteString (ByteString)
 import qualified Data.ByteString.Base64.URL as U
 import qualified Data.ByteString.Char8 as B
+import qualified Data.ByteString.Lazy as LB
 import Data.Functor (($>))
 import Data.Int (Int64)
 import Data.List (foldl', sortBy)
@@ -410,23 +421,23 @@ deleteUsersWithoutConns db = do
  forM_ userIds $ DB.execute db "DELETE FROM users WHERE user_id = ?" . Only
  pure userIds

-createClientService :: DB.Connection -> UserId -> SMPServer -> (C.KeyHash, TLS.Credential) -> IO ()
-createClientService db userId srv (kh, (cert, pk)) = do
+createClientService :: DB.Connection -> UserId -> SMPServer -> (C.KeyHash, TLS.Credential) -> IO ((C.KeyHash, TLS.Credential), Maybe ServiceId)
+createClientService db userId srv tlsCreds@(kh, (cert, pk)) = do
  serverKeyHash_ <- createServer db srv
-  DB.execute
-    db
-    [sql|
-      INSERT INTO client_services
-        (user_id, host, port, server_key_hash, service_cert_hash, service_cert, service_priv_key)
-      VALUES (?,?,?,?,?,?,?)
-      ON CONFLICT (user_id, host, port, server_key_hash)
-      DO UPDATE SET
-        service_cert_hash = EXCLUDED.service_cert_hash,
-        service_cert = EXCLUDED.service_cert,
-        service_priv_key = EXCLUDED.service_priv_key,
-        service_id = NULL
-    |]
-    (userId, host srv, port srv, serverKeyHash_, kh, cert, pk)
+  (rs :: [Only Int]) <-
+    DB.query
+      db
+      [sql|
+        INSERT INTO client_services
+          (user_id, host, port, server_key_hash, service_cert_hash, service_cert, service_priv_key)
+        VALUES (?,?,?,?,?,?,?)
+        ON CONFLICT (user_id, host, port, server_key_hash) DO NOTHING
+        RETURNING 1
+      |]
+      (userId, host srv, port srv, serverKeyHash_, kh, cert, pk)
+  if null rs
+    then fromMaybe (tlsCreds, Nothing) <$> getClientServiceCredentials db userId srv
+    else pure (tlsCreds, Nothing)

 getClientServiceCredentials :: DB.Connection -> UserId -> SMPServer -> IO (Maybe ((C.KeyHash, TLS.Credential), Maybe ServiceId))
 getClientServiceCredentials db userId srv =
@@ -557,14 +568,16 @@ createSndConn db gVar cData q@SndQueue {server} =
      insertSndQueue_ db connId q serverKeyHash_

 createConnRecord :: DB.Connection -> ConnId -> ConnData -> SConnectionMode c -> IO ()
-createConnRecord db connId ConnData {userId, connAgentVersion, enableNtfs, pqSupport} cMode =
+createConnRecord db connId ConnData {userId, connAgentVersion, enableNtfs, pqSupport, serviceRequestExpiresAt} cMode = do
+  createdAt <- getCurrentTime
  DB.execute
    db
    [sql|
      INSERT INTO connections
-        (user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs, pq_support, duplex_handshake) VALUES (?,?,?,?,?,?,?)
+        (user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs, pq_support, service_request_expires_at, duplex_handshake, created_at)
+        VALUES (?,?,?,?,?,?,?,?,?)
    |]
-    (userId, connId, cMode, connAgentVersion, BI enableNtfs, pqSupport, BI True)
+    (userId, connId, cMode, connAgentVersion, BI enableNtfs, pqSupport, serviceRequestExpiresAt, BI True, createdAt)

 deleteConnRecord :: DB.Connection -> ConnId -> IO ()
 deleteConnRecord db connId = DB.execute db "DELETE FROM connections WHERE conn_id = ?" (Only connId)
@@ -867,15 +880,15 @@ removeConfirmations db connId =
    (Only connId)

 createInvitation :: DB.Connection -> TVar ChaChaDRG -> NewInvitation -> IO (Either StoreError InvitationId)
-createInvitation db gVar NewInvitation {contactConnId, connReq, recipientConnInfo} =
+createInvitation db gVar NewInvitation {contactConnId, connReq, recipientConnInfo, serviceRequest} =
  createWithRandomId db gVar $ \invitationId ->
    DB.execute
      db
      [sql|
        INSERT INTO conn_invitations
-        (invitation_id, contact_conn_id, cr_invitation, recipient_conn_info, accepted) VALUES (?, ?, ?, ?, 0);
+        (invitation_id, contact_conn_id, cr_invitation, recipient_conn_info, accepted, service_request) VALUES (?, ?, ?, ?, 0, ?);
      |]
-      (Binary invitationId, contactConnId, connReq, Binary recipientConnInfo)
+      (Binary invitationId, contactConnId, connReq, Binary recipientConnInfo, BI serviceRequest)

 getInvitation :: DB.Connection -> String -> InvitationId -> IO (Either StoreError Invitation)
 getInvitation db cxt invitationId =
@@ -883,15 +896,15 @@ getInvitation db cxt invitationId =
    DB.query
      db
      [sql|
-        SELECT contact_conn_id, cr_invitation, recipient_conn_info, own_conn_info, accepted
+        SELECT contact_conn_id, cr_invitation, recipient_conn_info, own_conn_info, accepted, service_request, created_at
        FROM conn_invitations
        WHERE invitation_id = ?
          AND accepted = 0
      |]
      (Only (Binary invitationId))
  where
-    invitation (contactConnId_, connReq, recipientConnInfo, ownConnInfo, BI accepted) =
-      Invitation {invitationId, contactConnId_, connReq, recipientConnInfo, ownConnInfo, accepted}
+    invitation (contactConnId_, connReq, recipientConnInfo, ownConnInfo, BI accepted, BI serviceRequest, createdAt) =
+      Invitation {invitationId, contactConnId_, connReq, recipientConnInfo, ownConnInfo, accepted, serviceRequest, createdAt}

 acceptInvitation :: DB.Connection -> InvitationId -> ConnInfo -> IO ()
 acceptInvitation db invitationId ownConnInfo =
@@ -1030,6 +1043,24 @@ createSndMsgDelivery :: DB.Connection -> SndQueue -> InternalId -> IO ()
 createSndMsgDelivery db SndQueue {connId, dbQueueId} msgId =
  DB.execute db "INSERT INTO snd_message_deliveries (conn_id, snd_queue_id, internal_id) VALUES (?, ?, ?)" (connId, dbQueueId, msgId)

+-- copies every undelivered (failed = 0) delivery from one snd queue to another, for redundant delivery during fast rotation
+copyPendingSndDeliveries :: DB.Connection -> SndQueue -> SndQueue -> IO ()
+copyPendingSndDeliveries db SndQueue {connId, dbQueueId = fromQueueId} SndQueue {dbQueueId = toQueueId} =
+  DB.execute
+    db
+    [sql|
+      INSERT INTO snd_message_deliveries (conn_id, snd_queue_id, internal_id)
+      SELECT conn_id, ?, internal_id
+      FROM snd_message_deliveries
+      WHERE conn_id = ? AND snd_queue_id = ? AND failed = 0
+    |]
+    (toQueueId, connId, fromQueueId)
+
+countSndQueueDeliveries :: DB.Connection -> SndQueue -> IO Int
+countSndQueueDeliveries db SndQueue {connId, dbQueueId} =
+  maybeFirstRow' 0 fromOnly $
+    DB.query db "SELECT count(1) FROM snd_message_deliveries WHERE conn_id = ? AND snd_queue_id = ? AND failed = 0" (connId, dbQueueId)
+
 getSndMsgViaRcpt :: DB.Connection -> ConnId -> InternalSndId -> IO (Either StoreError SndMsg)
 getSndMsgViaRcpt db connId sndMsgId =
  firstRow toSndMsg (SEMsgNotFound "getSndMsgViaRcpt") $
@@ -1226,6 +1257,19 @@ toRcvMsg ((agentMsgId, internalTs, brokerId, brokerTs) :. (sndMsgId, integrity,
      msgReceipt = MsgReceipt <$> rcptInternalId_ <*> rcptStatus_
   in RcvMsg {internalId = InternalId agentMsgId, msgMeta, msgType, msgBody, internalHash, msgReceipt, userAck}

+incMsgRcvAttempts :: DB.Connection -> ConnId -> InternalId -> IO Int
+incMsgRcvAttempts db connId (InternalId msgId) =
+  fromOnly . head
+    <$> DB.query
+      db
+      [sql|
+        UPDATE rcv_messages
+        SET receive_attempts = receive_attempts + 1
+        WHERE conn_id = ? AND internal_id = ?
+        RETURNING receive_attempts
+      |]
+      (connId, msgId)
+
 checkRcvMsgHashExists :: DB.Connection -> ConnId -> ByteString -> IO Bool
 checkRcvMsgHashExists db connId hash =
  maybeFirstRow' False fromOnlyBI $
@@ -1345,11 +1389,11 @@ deleteSndMsgsExpired db ttl limit = do
    |]
    (cutoffTs, limit)

-createRatchetX3dhKeys :: DB.Connection -> ConnId -> C.PrivateKeyX448 -> C.PrivateKeyX448 -> Maybe CR.RcvPrivRKEMParams -> IO ()
-createRatchetX3dhKeys db connId x3dhPrivKey1 x3dhPrivKey2 pqPrivKem =
+createRatchetX3dhKeys :: DB.Connection -> ConnId -> CR.RcvE2EPrivRatchetParams 'C.X448 -> IO ()
+createRatchetX3dhKeys db connId (x3dhPrivKey1, x3dhPrivKey2, pqPrivKem) =
  DB.execute db "INSERT INTO ratchets (conn_id, x3dh_priv_key_1, x3dh_priv_key_2, pq_priv_kem) VALUES (?, ?, ?, ?)" (connId, x3dhPrivKey1, x3dhPrivKey2, pqPrivKem)

-getRatchetX3dhKeys :: DB.Connection -> ConnId -> IO (Either StoreError (C.PrivateKeyX448, C.PrivateKeyX448, Maybe CR.RcvPrivRKEMParams))
+getRatchetX3dhKeys :: DB.Connection -> ConnId -> IO (Either StoreError (CR.RcvE2EPrivRatchetParams 'C.X448))
 getRatchetX3dhKeys db connId =
  firstRow' keys SEX3dhKeysNotFound $
    DB.query db "SELECT x3dh_priv_key_1, x3dh_priv_key_2, pq_priv_kem FROM ratchets WHERE conn_id = ?" (Only connId)
@@ -1359,8 +1403,8 @@ getRatchetX3dhKeys db connId =
      _ -> Left SEX3dhKeysNotFound

 -- used to remember new keys when starting ratchet re-synchronization
-setRatchetX3dhKeys :: DB.Connection -> ConnId -> C.PrivateKeyX448 -> C.PrivateKeyX448 -> Maybe CR.RcvPrivRKEMParams -> IO ()
-setRatchetX3dhKeys db connId x3dhPrivKey1 x3dhPrivKey2 pqPrivKem =
+setRatchetX3dhKeys :: DB.Connection -> ConnId -> CR.RcvE2EPrivRatchetParams 'C.X448 -> IO ()
+setRatchetX3dhKeys db connId (x3dhPrivKey1, x3dhPrivKey2, pqPrivKem) =
  DB.execute
    db
    [sql|
@@ -1370,6 +1414,60 @@ setRatchetX3dhKeys db connId x3dhPrivKey1 x3dhPrivKey2 pqPrivKem =
    |]
    (x3dhPrivKey1, x3dhPrivKey2, pqPrivKem, connId)

+createAddressRatchetKeys :: DB.Connection -> ConnId -> (RatchetKeyId, CR.RcvE2EPrivRatchetParams 'C.X448) -> IO ()
+createAddressRatchetKeys db connId (ratchetKeyId, (x3dhPrivKey1, x3dhPrivKey2, pqPrivKem)) =
+  DB.execute
+    db
+    [sql|
+      INSERT INTO address_ratchet_keys
+        (conn_id, ratchet_key_id, x3dh_priv_key_1, x3dh_priv_key_2, pq_priv_kem)
+      VALUES (?, ?, ?, ?, ?)
+    |]
+    (connId, ratchetKeyId, x3dhPrivKey1, x3dhPrivKey2, pqPrivKem)
+
+getCurrentAddressRatchetKeys :: DB.Connection -> ConnId -> IO (Either StoreError (RatchetKeyId, CR.RcvE2EPrivRatchetParams 'C.X448))
+getCurrentAddressRatchetKeys db connId =
+  firstRow (\(Only rkId :. pks) -> (rkId, pks)) SEX3dhKeysNotFound $
+    DB.query
+      db
+      [sql|
+        SELECT ratchet_key_id, x3dh_priv_key_1, x3dh_priv_key_2, pq_priv_kem
+        FROM address_ratchet_keys
+        WHERE conn_id = ?
+        ORDER BY address_ratchet_key_id DESC
+        LIMIT 1
+      |]
+      (Only connId)
+
+getAddressRatchetKeys :: DB.Connection -> ConnId -> RatchetKeyId -> IO (Either StoreError (CR.RcvE2EPrivRatchetParams 'C.X448))
+getAddressRatchetKeys db connId ratchetKeyId =
+  firstRow id SEX3dhKeysNotFound $
+    DB.query
+      db
+      [sql|
+        SELECT x3dh_priv_key_1, x3dh_priv_key_2, pq_priv_kem
+        FROM address_ratchet_keys
+        WHERE conn_id = ? AND ratchet_key_id = ?
+      |]
+      (connId, ratchetKeyId)
+
+deleteOldAddressRatchetKeys :: DB.Connection -> ConnId -> Int -> IO ()
+deleteOldAddressRatchetKeys db connId keep =
+  DB.execute
+    db
+    [sql|
+      DELETE FROM address_ratchet_keys
+      WHERE conn_id = ?
+        AND address_ratchet_key_id NOT IN (
+          SELECT address_ratchet_key_id
+          FROM address_ratchet_keys
+          WHERE conn_id = ?
+          ORDER BY address_ratchet_key_id DESC
+          LIMIT ?
+        )
+    |]
+    (connId, connId, keep)
+
 createSndRatchet :: DB.Connection -> ConnId -> RatchetX448 -> CR.AE2ERatchetParams 'C.X448 -> IO ()
 createSndRatchet db connId ratchetState (CR.AE2ERatchetParams s (CR.E2ERatchetParams _ x3dhPubKey1 x3dhPubKey2 pqPubKem)) =
  DB.execute
@@ -2061,6 +2159,21 @@ instance ConnectionModeI c => ToField (ConnectionRequestUri c) where toField = t

 instance (E.Typeable c, ConnectionModeI c) => FromField (ConnectionRequestUri c) where fromField = blobFieldDecoder strDecode

+instance ToField RatchetKeyId where toField (RatchetKeyId s) = toField $ Binary s
+
+instance FromField RatchetKeyId where fromField = blobFieldDecoder $ Right . RatchetKeyId
+
+instance ToField ContactRequest where
+  toField = toField . Binary . \case
+    CRInvitation cr -> strEncode cr
+    CRInvitationDR dr -> LB.toStrict $ J.encode dr
+
+instance FromField ContactRequest where
+  fromField = blobFieldDecoder $ \bs ->
+    if "{" `B.isPrefixOf` bs
+      then CRInvitationDR <$> J.eitherDecodeStrict' bs
+      else CRInvitation <$> strDecode bs
+
 instance ToField ConnectionMode where toField = toField . decodeLatin1 . strEncode

 instance FromField ConnectionMode where fromField = fromTextField_ connModeT
@@ -2336,14 +2449,14 @@ getSubscriptionServers db onlyNeeded =
    toUserServer (userId, host, port, keyHash) = (userId, SMPServer host port keyHash)

 -- TODO [certs rcv] check index for getting queues with service present
-getUserServerRcvQueueSubs :: DB.Connection -> UserId -> SMPServer -> Bool -> ServiceAssoc -> IO [RcvQueueSub]
-getUserServerRcvQueueSubs db userId (SMPServer h p kh) onlyNeeded hasService =
-  map toRcvQueueSub
-    <$> DB.query
-      db
-      (rcvQueueSubQuery <> toSubscribe <> " c.deleted = 0 AND q.deleted = 0 AND c.user_id = ? AND q.host = ? AND q.port = ? AND COALESCE(q.server_key_hash, s.key_hash) = ?" <> serviceCond)
-      (userId, h, p, kh)
+getUserServerRcvQueueSubs :: DB.Connection -> UserId -> SMPServer -> Bool -> ServiceAssoc -> Int -> Maybe SMP.RecipientId -> IO [RcvQueueSub]
+getUserServerRcvQueueSubs db userId (SMPServer h p kh) onlyNeeded hasService limit cursor_ =
+  map toRcvQueueSub <$> case cursor_ of
+    Nothing -> DB.query db (q <> orderLimit) (userId, h, p, kh, limit)
+    Just cursor -> DB.query db (q <> " AND q.rcv_id > ? " <> orderLimit) (userId, h, p, kh, cursor, limit)
  where
+    q = rcvQueueSubQuery <> toSubscribe <> " c.deleted = 0 AND q.deleted = 0 AND c.user_id = ? AND q.host = ? AND q.port = ? AND COALESCE(q.server_key_hash, s.key_hash) = ?" <> serviceCond
+    orderLimit = " ORDER BY q.rcv_id LIMIT ?"
    toSubscribe
      | onlyNeeded = " WHERE q.to_subscribe = 1 AND "
      | otherwise = " WHERE "
@@ -2385,12 +2498,18 @@ unassocUserServerRcvQueueSubs' db userId srv@(SMPServer h p kh) = do
 unsetQueuesToSubscribe :: DB.Connection -> IO ()
 unsetQueuesToSubscribe db = DB.execute_ db "UPDATE rcv_queues SET to_subscribe = 0 WHERE to_subscribe = 1"

-setRcvServiceAssocs :: SMPQueue q => DB.Connection -> [q] -> IO ()
-setRcvServiceAssocs db rqs = do
+setRcvServiceAssocs :: SMPQueue q => DB.Connection -> SMPServer -> [q] -> IO ()
+setRcvServiceAssocs db ProtocolServer {host, port} rqs =
 #if defined(dbPostgres)
-  DB.execute db "UPDATE rcv_queues SET rcv_service_assoc = 1 WHERE rcv_id IN ?" $ Only $ In (map queueId rqs)
+  DB.execute
+    db
+    "UPDATE rcv_queues SET rcv_service_assoc = 1 WHERE host = ? AND port = ? AND rcv_id IN ?"
+    (host, port, In (map queueId rqs))
 #else
-  DB.executeMany db "UPDATE rcv_queues SET rcv_service_assoc = 1 WHERE rcv_id = ?" $ map (Only . queueId) rqs
+  DB.executeMany
+    db
+    "UPDATE rcv_queues SET rcv_service_assoc = 1 WHERE host = ? AND port = ? AND rcv_id = ?"
+    (map (\q -> (host, port, queueId q)) rqs)
 #endif

 removeRcvServiceAssocs :: DB.Connection -> UserId -> SMPServer -> IO ()
@@ -2529,7 +2648,7 @@ getConnsData_ deleted' db connIds =
      db
      [sql|
        SELECT user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs,
-          last_external_snd_msg_id, deleted, ratchet_sync_state, pq_support
+          last_external_snd_msg_id, deleted, ratchet_sync_state, pq_support, service_request_expires_at
        FROM connections
        WHERE conn_id IN ? AND deleted = ?
      |]
@@ -2564,7 +2683,7 @@ getConnData deleted' forUpdate db connId' =
      db
      ( [sql|
          SELECT user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs,
-            last_external_snd_msg_id, deleted, ratchet_sync_state, pq_support
+            last_external_snd_msg_id, deleted, ratchet_sync_state, pq_support, service_request_expires_at
          FROM connections
          WHERE conn_id = ? AND deleted = ?
        |]
@@ -2581,9 +2700,9 @@ lockConnForUpdate db connId = do
 #endif
  pure ()

-rowToConnData :: (UserId, ConnId, ConnectionMode, VersionSMPA, Maybe BoolInt, PrevExternalSndId, BoolInt, RatchetSyncState, PQSupport) -> (ConnData, ConnectionMode)
-rowToConnData (userId, connId, cMode, connAgentVersion, enableNtfs_, lastExternalSndId, BI deleted, ratchetSyncState, pqSupport) =
-  (ConnData {userId, connId, connAgentVersion, enableNtfs = maybe True unBI enableNtfs_, lastExternalSndId, deleted, ratchetSyncState, pqSupport}, cMode)
+rowToConnData :: (UserId, ConnId, ConnectionMode, VersionSMPA, Maybe BoolInt, PrevExternalSndId, BoolInt, RatchetSyncState, PQSupport, Maybe UTCTime) -> (ConnData, ConnectionMode)
+rowToConnData (userId, connId, cMode, connAgentVersion, enableNtfs_, lastExternalSndId, BI deleted, ratchetSyncState, pqSupport, serviceRequestExpiresAt) =
+  (ConnData {userId, connId, connAgentVersion, enableNtfs = maybe True unBI enableNtfs_, lastExternalSndId, deleted, ratchetSyncState, pqSupport, serviceRequestExpiresAt}, cMode)

 setConnDeleted :: DB.Connection -> Bool -> ConnId -> IO ()
 setConnDeleted db waitDelivery connId
@@ -2612,6 +2731,14 @@ updateNewConnJoin db connId aVersion pqSupport enableNtfs =
 getDeletedConnIds :: DB.Connection -> IO [ConnId]
 getDeletedConnIds db = map fromOnly <$> DB.query db "SELECT conn_id FROM connections WHERE deleted = ?" (Only (BI True))

+getExpiredServiceConns :: DB.Connection -> UTCTime -> IO [ConnId]
+getExpiredServiceConns db now =
+  map fromOnly <$> DB.query db "SELECT conn_id FROM connections WHERE service_request_expires_at < ? AND deleted = 0 AND deleted_at_wait_delivery IS NULL" (Only now)
+
+deleteExpiredServiceRequests :: DB.Connection -> UTCTime -> IO ()
+deleteExpiredServiceRequests db expireTs =
+  DB.execute db "DELETE FROM conn_invitations WHERE service_request = 1 AND created_at < ?" (Only expireTs)
+
 getDeletedWaitingDeliveryConnIds :: DB.Connection -> IO [ConnId]
 getDeletedWaitingDeliveryConnIds db =
  map fromOnly <$> DB.query_ db "SELECT conn_id FROM connections WHERE deleted_at_wait_delivery IS NOT NULL"
@@ -11,7 +11,9 @@ import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250702_conn_invitati
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251009_queue_to_subscribe
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251010_client_notices
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251230_strict_tables
-import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260115_service_certs
+import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260410_receive_attempts
+import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260411_service_certs
+import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260712_address_dr_rpc
 import Simplex.Messaging.Agent.Store.Shared (Migration (..))

 schemaMigrations :: [(String, Text, Maybe Text)]
@@ -23,7 +25,9 @@ schemaMigrations =
    ("20251009_queue_to_subscribe", m20251009_queue_to_subscribe, Just down_m20251009_queue_to_subscribe),
    ("20251010_client_notices", m20251010_client_notices, Just down_m20251010_client_notices),
    ("20251230_strict_tables", m20251230_strict_tables, Just down_m20251230_strict_tables),
-    ("20260115_service_certs", m20260115_service_certs, Just down_m20260115_service_certs)
+    ("20260410_receive_attempts", m20260410_receive_attempts, Just down_m20260410_receive_attempts),
+    ("20260411_service_certs", m20260411_service_certs, Just down_m20260411_service_certs),
+    ("20260712_address_dr_rpc", m20260712_address_dr_rpc, Just down_m20260712_address_dr_rpc)
  ]

 -- | The list of migrations in ascending order by date
@@ -0,0 +1,19 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260410_receive_attempts where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+m20260410_receive_attempts :: Text
+m20260410_receive_attempts =
+  [r|
+ALTER TABLE rcv_messages ADD COLUMN receive_attempts SMALLINT NOT NULL DEFAULT 0;
+|]
+
+down_m20260410_receive_attempts :: Text
+down_m20260410_receive_attempts =
+  [r|
+ALTER TABLE rcv_messages DROP COLUMN receive_attempts;
+|]
@@ -1,14 +1,14 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}

-module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260115_service_certs where
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260411_service_certs where

 import Data.Text (Text)
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.Util
 import Text.RawString.QQ (r)

-m20260115_service_certs :: Text
-m20260115_service_certs =
+m20260411_service_certs :: Text
+m20260411_service_certs =
  createXorHashFuncs <> [r|
 CREATE TABLE client_services(
  user_id BIGINT NOT NULL REFERENCES users ON UPDATE RESTRICT ON DELETE CASCADE,
@@ -92,8 +92,8 @@ AFTER UPDATE ON rcv_queues
 FOR EACH ROW EXECUTE PROCEDURE on_rcv_queue_update();
    |]

-down_m20260115_service_certs :: Text
-down_m20260115_service_certs =
+down_m20260411_service_certs :: Text
+down_m20260411_service_certs =
  [r|
 DROP TRIGGER tr_rcv_queue_insert ON rcv_queues;
 DROP TRIGGER tr_rcv_queue_delete ON rcv_queues;
@@ -0,0 +1,42 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20260712_address_dr_rpc where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+m20260712_address_dr_rpc :: Text
+m20260712_address_dr_rpc =
+  [r|
+CREATE TABLE address_ratchet_keys(
+  address_ratchet_key_id BIGSERIAL PRIMARY KEY,
+  conn_id BYTEA NOT NULL REFERENCES connections ON DELETE CASCADE,
+  ratchet_key_id BYTEA NOT NULL,
+  x3dh_priv_key_1 BYTEA NOT NULL,
+  x3dh_priv_key_2 BYTEA NOT NULL,
+  pq_priv_kem BYTEA,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT (now())
+);
+
+CREATE UNIQUE INDEX idx_address_ratchet_keys ON address_ratchet_keys(conn_id, ratchet_key_id);
+
+ALTER TABLE conn_invitations ADD COLUMN service_request SMALLINT NOT NULL DEFAULT 0; -- service side: received request is a service request (SREQ) not a contact request (REQ)
+ALTER TABLE connections ADD COLUMN created_at TIMESTAMPTZ NOT NULL DEFAULT '1970-01-01 00:00:00';
+ALTER TABLE connections ADD COLUMN service_request_expires_at TIMESTAMPTZ; -- client side: requester's outstanding service request; the time the client stops waiting for the response
+
+CREATE INDEX idx_connections_deleted ON connections(deleted);
+CREATE INDEX idx_connections_service_request_expires_at ON connections(service_request_expires_at);
+  |]
+
+down_m20260712_address_dr_rpc :: Text
+down_m20260712_address_dr_rpc =
+  [r|
+DROP INDEX idx_connections_service_request_expires_at;
+DROP INDEX idx_connections_deleted;
+ALTER TABLE connections DROP COLUMN service_request_expires_at;
+ALTER TABLE connections DROP COLUMN created_at;
+ALTER TABLE conn_invitations DROP COLUMN service_request;
+DROP INDEX idx_address_ratchet_keys;
+DROP TABLE address_ratchet_keys;
+  |]
@@ -104,6 +104,31 @@ CREATE AGGREGATE smp_agent_test_protocol_schema.xor_aggregate(bytea) (
 SET default_table_access_method = heap;


+CREATE TABLE smp_agent_test_protocol_schema.address_ratchet_keys (
+    address_ratchet_key_id bigint NOT NULL,
+    conn_id bytea NOT NULL,
+    ratchet_key_id bytea NOT NULL,
+    x3dh_priv_key_1 bytea NOT NULL,
+    x3dh_priv_key_2 bytea NOT NULL,
+    pq_priv_kem bytea,
+    created_at timestamp with time zone DEFAULT now() NOT NULL
+);
+
+
+
+CREATE SEQUENCE smp_agent_test_protocol_schema.address_ratchet_keys_address_ratchet_key_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+
+
+ALTER SEQUENCE smp_agent_test_protocol_schema.address_ratchet_keys_address_ratchet_key_id_seq OWNED BY smp_agent_test_protocol_schema.address_ratchet_keys.address_ratchet_key_id;
+
+
+
 CREATE TABLE smp_agent_test_protocol_schema.client_notices (
    client_notice_id bigint NOT NULL,
    protocol text NOT NULL,
@@ -194,7 +219,8 @@ CREATE TABLE smp_agent_test_protocol_schema.conn_invitations (
    recipient_conn_info bytea NOT NULL,
    accepted smallint DEFAULT 0 NOT NULL,
    own_conn_info bytea,
-    created_at timestamp with time zone DEFAULT now() NOT NULL
+    created_at timestamp with time zone DEFAULT now() NOT NULL,
+    service_request smallint DEFAULT 0 NOT NULL
 );


@@ -215,7 +241,9 @@ CREATE TABLE smp_agent_test_protocol_schema.connections (
    user_id bigint NOT NULL,
    ratchet_sync_state text DEFAULT 'ok'::text NOT NULL,
    deleted_at_wait_delivery timestamp with time zone,
-    pq_support smallint DEFAULT 0 NOT NULL
+    pq_support smallint DEFAULT 0 NOT NULL,
+    created_at timestamp with time zone DEFAULT '1970-01-01 00:00:00+01'::timestamp with time zone NOT NULL,
+    service_request_expires_at timestamp with time zone
 );


@@ -527,7 +555,8 @@ CREATE TABLE smp_agent_test_protocol_schema.rcv_messages (
    external_prev_snd_hash bytea NOT NULL,
    integrity bytea NOT NULL,
    user_ack smallint DEFAULT 0,
-    rcv_queue_id bigint NOT NULL
+    rcv_queue_id bigint NOT NULL,
+    receive_attempts smallint DEFAULT 0 NOT NULL
 );


@@ -846,6 +875,15 @@ ALTER TABLE smp_agent_test_protocol_schema.xftp_servers ALTER COLUMN xftp_server



+ALTER TABLE ONLY smp_agent_test_protocol_schema.address_ratchet_keys ALTER COLUMN address_ratchet_key_id SET DEFAULT nextval('smp_agent_test_protocol_schema.address_ratchet_keys_address_ratchet_key_id_seq'::regclass);
+
+
+
+ALTER TABLE ONLY smp_agent_test_protocol_schema.address_ratchet_keys
+    ADD CONSTRAINT address_ratchet_keys_pkey PRIMARY KEY (address_ratchet_key_id);
+
+
+
 ALTER TABLE ONLY smp_agent_test_protocol_schema.client_notices
    ADD CONSTRAINT client_notices_pkey PRIMARY KEY (client_notice_id);

@@ -1031,6 +1069,10 @@ ALTER TABLE ONLY smp_agent_test_protocol_schema.xftp_servers



+CREATE UNIQUE INDEX idx_address_ratchet_keys ON smp_agent_test_protocol_schema.address_ratchet_keys USING btree (conn_id, ratchet_key_id);
+
+
+
 CREATE UNIQUE INDEX idx_client_notices_entity ON smp_agent_test_protocol_schema.client_notices USING btree (protocol, host, port, entity_id);


@@ -1055,6 +1097,14 @@ CREATE INDEX idx_conn_invitations_contact_conn_id ON smp_agent_test_protocol_sch



+CREATE INDEX idx_connections_deleted ON smp_agent_test_protocol_schema.connections USING btree (deleted);
+
+
+
+CREATE INDEX idx_connections_service_request_expires_at ON smp_agent_test_protocol_schema.connections USING btree (service_request_expires_at);
+
+
+
 CREATE INDEX idx_connections_user ON smp_agent_test_protocol_schema.connections USING btree (user_id);


@@ -1267,6 +1317,11 @@ CREATE TRIGGER tr_rcv_queue_update AFTER UPDATE ON smp_agent_test_protocol_schem



+ALTER TABLE ONLY smp_agent_test_protocol_schema.address_ratchet_keys
+    ADD CONSTRAINT address_ratchet_keys_conn_id_fkey FOREIGN KEY (conn_id) REFERENCES smp_agent_test_protocol_schema.connections(conn_id) ON DELETE CASCADE;
+
+
+
 ALTER TABLE ONLY smp_agent_test_protocol_schema.client_services
    ADD CONSTRAINT client_services_host_port_fkey FOREIGN KEY (host, port) REFERENCES smp_agent_test_protocol_schema.servers(host, port) ON DELETE RESTRICT;

@@ -50,7 +50,6 @@ import Data.Bits (xor)
 import Data.ByteArray (ScrubbedBytes)
 import qualified Data.ByteArray as BA
 import Data.ByteString (ByteString)
-import qualified Data.ByteString as B
 import Data.Functor (($>))
 import Data.IORef
 import Data.Maybe (fromMaybe)
@@ -47,7 +47,9 @@ import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250702_conn_invitation
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251009_queue_to_subscribe
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251010_client_notices
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251230_strict_tables
-import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260115_service_certs
+import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260410_receive_attempts
+import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260411_service_certs
+import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260712_address_dr_rpc
 import Simplex.Messaging.Agent.Store.Shared (Migration (..))

 schemaMigrations :: [(String, Query, Maybe Query)]
@@ -95,7 +97,9 @@ schemaMigrations =
    ("m20251009_queue_to_subscribe", m20251009_queue_to_subscribe, Just down_m20251009_queue_to_subscribe),
    ("m20251010_client_notices", m20251010_client_notices, Just down_m20251010_client_notices),
    ("m20251230_strict_tables", m20251230_strict_tables, Just down_m20251230_strict_tables),
-    ("m20260115_service_certs", m20260115_service_certs, Just down_m20260115_service_certs)
+    ("m20260410_receive_attempts", m20260410_receive_attempts, Just down_m20260410_receive_attempts),
+    ("m20260411_service_certs", m20260411_service_certs, Just down_m20260411_service_certs),
+    ("m20260712_address_dr_rpc", m20260712_address_dr_rpc, Just down_m20260712_address_dr_rpc)
  ]

 -- | The list of migrations in ascending order by date
@@ -0,0 +1,18 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260410_receive_attempts where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20260410_receive_attempts :: Query
+m20260410_receive_attempts =
+  [sql|
+ALTER TABLE rcv_messages ADD COLUMN receive_attempts INTEGER NOT NULL DEFAULT 0;
+|]
+
+down_m20260410_receive_attempts :: Query
+down_m20260410_receive_attempts =
+  [sql|
+ALTER TABLE rcv_messages DROP COLUMN receive_attempts;
+|]
@@ -1,12 +1,12 @@
 {-# LANGUAGE QuasiQuotes #-}

-module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260115_service_certs where
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260411_service_certs where

 import Database.SQLite.Simple (Query)
 import Database.SQLite.Simple.QQ (sql)

-m20260115_service_certs :: Query
-m20260115_service_certs =
+m20260411_service_certs :: Query
+m20260411_service_certs =
  [sql|
 CREATE TABLE client_services(
  user_id INTEGER NOT NULL REFERENCES users ON DELETE CASCADE,
@@ -76,8 +76,8 @@ BEGIN
 END;
  |]

-down_m20260115_service_certs :: Query
-down_m20260115_service_certs =
+down_m20260411_service_certs :: Query
+down_m20260411_service_certs =
  [sql|
 DROP TRIGGER tr_rcv_queue_insert;
 DROP TRIGGER tr_rcv_queue_delete;
@@ -0,0 +1,41 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20260712_address_dr_rpc where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20260712_address_dr_rpc :: Query
+m20260712_address_dr_rpc =
+  [sql|
+CREATE TABLE address_ratchet_keys(
+  address_ratchet_key_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
+  ratchet_key_id BLOB NOT NULL,
+  x3dh_priv_key_1 BLOB NOT NULL,
+  x3dh_priv_key_2 BLOB NOT NULL,
+  pq_priv_kem BLOB,
+  created_at TEXT NOT NULL DEFAULT(datetime('now'))
+) STRICT;
+
+CREATE UNIQUE INDEX idx_address_ratchet_keys ON address_ratchet_keys(conn_id, ratchet_key_id);
+
+ALTER TABLE conn_invitations ADD COLUMN service_request INTEGER NOT NULL DEFAULT 0; -- service side: received request is a service request (SREQ) not a contact request (REQ)
+ALTER TABLE connections ADD COLUMN created_at TEXT NOT NULL DEFAULT('1970-01-01 00:00:00');
+ALTER TABLE connections ADD COLUMN service_request_expires_at TEXT; -- client side: requester's outstanding service request; the time the client stops waiting for the response
+
+CREATE INDEX idx_connections_deleted ON connections(deleted);
+CREATE INDEX idx_connections_service_request_expires_at ON connections(service_request_expires_at);
+  |]
+
+down_m20260712_address_dr_rpc :: Query
+down_m20260712_address_dr_rpc =
+  [sql|
+DROP INDEX idx_connections_service_request_expires_at;
+DROP INDEX idx_connections_deleted;
+ALTER TABLE connections DROP COLUMN service_request_expires_at;
+ALTER TABLE connections DROP COLUMN created_at;
+ALTER TABLE conn_invitations DROP COLUMN service_request;
+DROP INDEX idx_address_ratchet_keys;
+DROP TABLE address_ratchet_keys;
+  |]
@@ -27,7 +27,9 @@ CREATE TABLE connections(
  REFERENCES users ON DELETE CASCADE,
  ratchet_sync_state TEXT NOT NULL DEFAULT 'ok',
  deleted_at_wait_delivery TEXT,
-  pq_support INTEGER NOT NULL DEFAULT 0
+  pq_support INTEGER NOT NULL DEFAULT 0,
+  created_at TEXT NOT NULL DEFAULT('1970-01-01 00:00:00'),
+  service_request_expires_at TEXT
 ) WITHOUT ROWID, STRICT;
 CREATE TABLE rcv_queues(
  host TEXT NOT NULL,
@@ -120,6 +122,7 @@ CREATE TABLE rcv_messages(
  integrity BLOB NOT NULL,
  user_ack INTEGER NULL DEFAULT 0,
  rcv_queue_id INTEGER CHECK(rcv_queue_id NOT NULL),
+  receive_attempts INTEGER NOT NULL DEFAULT 0,
  PRIMARY KEY(conn_id, internal_rcv_id),
  FOREIGN KEY(conn_id, internal_id) REFERENCES messages
  ON DELETE CASCADE
@@ -163,6 +166,8 @@ CREATE TABLE conn_invitations(
  accepted INTEGER NOT NULL DEFAULT 0,
  own_conn_info BLOB,
  created_at TEXT NOT NULL DEFAULT(datetime('now'))
+  ,
+  service_request INTEGER NOT NULL DEFAULT 0
 ) WITHOUT ROWID, STRICT;
 CREATE TABLE ratchets(
  conn_id BLOB NOT NULL PRIMARY KEY REFERENCES connections
@@ -464,6 +469,15 @@ CREATE TABLE client_services(
  service_queue_ids_hash BLOB NOT NULL DEFAULT x'00000000000000000000000000000000',
  FOREIGN KEY(host, port) REFERENCES servers ON UPDATE CASCADE ON DELETE RESTRICT
 ) STRICT;
+CREATE TABLE address_ratchet_keys(
+  address_ratchet_key_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
+  ratchet_key_id BLOB NOT NULL,
+  x3dh_priv_key_1 BLOB NOT NULL,
+  x3dh_priv_key_2 BLOB NOT NULL,
+  pq_priv_kem BLOB,
+  created_at TEXT NOT NULL DEFAULT(datetime('now'))
+) STRICT;
 CREATE UNIQUE INDEX idx_rcv_queues_ntf ON rcv_queues(host, port, ntf_id);
 CREATE UNIQUE INDEX idx_rcv_queue_id ON rcv_queues(conn_id, rcv_queue_id);
 CREATE UNIQUE INDEX idx_snd_queue_id ON snd_queues(conn_id, snd_queue_id);
@@ -614,6 +628,14 @@ CREATE UNIQUE INDEX idx_server_certs_user_id_host_port ON client_services(
  server_key_hash
 );
 CREATE INDEX idx_server_certs_host_port ON client_services(host, port);
+CREATE UNIQUE INDEX idx_address_ratchet_keys ON address_ratchet_keys(
+  conn_id,
+  ratchet_key_id
+);
+CREATE INDEX idx_connections_deleted ON connections(deleted);
+CREATE INDEX idx_connections_service_request_expires_at ON connections(
+  service_request_expires_at
+);
 CREATE TRIGGER tr_rcv_queue_insert
 AFTER INSERT ON rcv_queues
 FOR EACH ROW
@@ -73,6 +73,8 @@ module Simplex.Messaging.Client
    deleteSMPQueues,
    connectSMPProxiedRelay,
    proxySMPMessage,
+    proxyResolveName,
+    directResolveName,
    forwardSMPTransmission,
    getSMPQueueInfo,
    sendProtocolCommand,
@@ -164,6 +166,7 @@ import Simplex.Messaging.Parsers (defaultJSON, dropPrefix, enumJSON, sumTypeJSON
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.Protocol.Types
 import Simplex.Messaging.Server.QueueStore.QueueInfo
+import Simplex.Messaging.SimplexName (SimplexDomain)
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport
@@ -224,10 +227,10 @@ smpClientStub g sessionId thVersion thAuth = do
              thServerVRange = supportedServerSMPRelayVRange,
              thAuth,
              blockSize = smpBlockSize,
-              implySessId = thVersion >= authCmdsSMPVersion,
+              implySessId = True,
              encryptBlock = Nothing,
-              batch = True,
-              serviceAuth = thVersion >= serviceCertsSMPVersion
+              serviceAuth = thVersion >= serviceCertsSMPVersion,
+              serverInfo = Nothing
            },
        sessionTs = ts,
        client_ =
@@ -971,7 +974,7 @@ deleteSMPQueueLink :: SMPClient -> NetworkRequestMode -> RcvPrivateAuthKey -> Re
 deleteSMPQueueLink = okSMPCommand LDEL
 {-# INLINE deleteSMPQueueLink #-}

-- | Get 1-time inviation SMP queue link data and secure the queue via queue link ID.
+-- | Get 1-time invitation SMP queue link data and secure the queue via queue link ID.
 secureGetSMPQueueLink :: SMPClient -> NetworkRequestMode -> SndPrivateAuthKey -> LinkId -> ExceptT SMPClientError IO (SenderId, QueueLinkData)
 secureGetSMPQueueLink c nm spKey lnkId =
  sendSMPCommand c nm (Just spKey) lnkId (LKEY $ C.toPublic spKey) >>= \case
@@ -1046,6 +1049,33 @@ sendSMPMessage c nm spKey sId flags msg =
 proxySMPMessage :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> Maybe SndPrivateAuthKey -> SenderId -> MsgFlags -> MsgBody -> ExceptT SMPClientError IO (Either ProxyClientError ())
 proxySMPMessage c nm proxiedRelay spKey sId flags msg = proxyOKSMPCommand c nm proxiedRelay spKey sId (SEND flags msg)

+-- | Resolve a public-namespace name via PFWD. Preferred path - hides the
+-- client IP from the resolver. Mirrors `proxySMPMessage`'s shape; routes
+-- through `proxySMPCommand` and pattern-matches the expected RNAME response.
+-- Version-gated on the destination relay (mirrors `connectSMPProxiedRelay`):
+-- the client never sends RSLV to a relay that predates names support.
+proxyResolveName :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> SimplexDomain -> ExceptT SMPClientError IO (Either ProxyClientError NameRecord)
+proxyResolveName c nm proxiedRelay name
+  | prVersion proxiedRelay >= namesSMPVersion =
+      proxySMPCommand c nm proxiedRelay Nothing NoEntity (RSLV name) >>= \case
+        Right (RNAME nr) -> pure $ Right nr
+        Right r -> throwE $ unexpectedResponse r
+        Left e -> pure $ Left e
+  | otherwise = throwE $ PCETransportError TEVersion
+
+-- | Direct (non-PFWD) name resolution. Exposes the client IP to the resolver;
+-- callers that want anonymity should use `proxyResolveName` via the standard
+-- proxy fallback in the agent. RSLV requires no entity ID or authorization
+-- (see `noAuthCmd` in Protocol.hs). Version-gated on the session here, not the
+-- encoder, so an old server never receives RSLV.
+directResolveName :: SMPClient -> NetworkRequestMode -> SimplexDomain -> ExceptT SMPClientError IO NameRecord
+directResolveName c nm name
+  | thVersion (thParams c) >= namesSMPVersion =
+      sendProtocolCommand c nm Nothing NoEntity (Cmd SResolver (RSLV name)) >>= \case
+        RNAME nr -> pure nr
+        r -> throwE $ unexpectedResponse r
+  | otherwise = throwE $ PCETransportError TEVersion
+
 -- | Acknowledge message delivery (server deletes the message).
 --
 -- https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#acknowledge-message-delivery
@@ -1080,17 +1110,15 @@ deleteSMPQueues = okSMPCommands DEL
 -- send PRXY :: SMPServer -> Maybe BasicAuth -> Command Sender
 -- receives PKEY :: SessionId -> X.CertificateChain -> X.SignedExact X.PubKey -> BrokerMsg
 connectSMPProxiedRelay :: SMPClient -> NetworkRequestMode -> SMPServer -> Maybe BasicAuth -> ExceptT SMPClientError IO ProxiedRelay
-connectSMPProxiedRelay c@ProtocolClient {client_ = PClient {tcpConnectTimeout, tcpTimeout}} nm relayServ@ProtocolServer {port = relayPort, keyHash = C.KeyHash kh} proxyAuth
-  | thVersion (thParams c) >= sendingProxySMPVersion =
-      sendProtocolCommand_ c nm Nothing tOut Nothing NoEntity (Cmd SProxiedClient (PRXY relayServ proxyAuth)) >>= \case
-        PKEY sId vr (CertChainPubKey chain key) ->
-          case supportedClientSMPRelayVRange `compatibleVersion` vr of
-            Nothing -> throwE $ transportErr TEVersion
-            Just (Compatible v) -> do
-              relayKey <- liftEitherWith (const $ transportErr $ TEHandshake IDENTITY) =<< liftIO (runExceptT $ validateRelay chain key)
-              pure $ ProxiedRelay sId v proxyAuth relayKey
-        r -> throwE $ unexpectedResponse r
-  | otherwise = throwE $ PCETransportError TEVersion
+connectSMPProxiedRelay c@ProtocolClient {client_ = PClient {tcpConnectTimeout, tcpTimeout}} nm relayServ@ProtocolServer {port = relayPort, keyHash = C.KeyHash kh} proxyAuth =
+  sendProtocolCommand_ c nm Nothing tOut Nothing NoEntity (Cmd SProxiedClient (PRXY relayServ proxyAuth)) >>= \case
+    PKEY sId vr (CertChainPubKey chain key) ->
+      case supportedClientSMPRelayVRange `compatibleVersion` vr of
+        Nothing -> throwE $ transportErr TEVersion
+        Just (Compatible v) -> do
+          relayKey <- liftEitherWith (const $ transportErr $ TEHandshake IDENTITY) =<< liftIO (runExceptT $ validateRelay chain key)
+          pure $ ProxiedRelay sId v proxyAuth relayKey
+    r -> throwE $ unexpectedResponse r
  where
    tOut = Just $ netTimeoutInt tcpConnectTimeout nm + netTimeoutInt tcpTimeout nm
    transportErr = PCEProtocolError . PROXY . BROKER . TRANSPORT
@@ -1321,7 +1349,7 @@ sendProtocolCommand c nm = sendProtocolCommand_ c nm Nothing Nothing
 --
 -- Please note: if nonce is passed it is also used as a correlation ID
 sendProtocolCommand_ :: forall v err msg. Protocol v err msg => ProtocolClient v err msg -> NetworkRequestMode -> Maybe C.CbNonce -> Maybe Int -> Maybe C.APrivateAuthKey -> EntityId -> ProtoCommand msg -> ExceptT (ProtocolClientError err) IO msg
-sendProtocolCommand_ c@ProtocolClient {client_ = PClient {sndQ}, thParams = THandleParams {batch, blockSize, serviceAuth}} nm nonce_ tOut pKey entId cmd =
+sendProtocolCommand_ c@ProtocolClient {client_ = PClient {sndQ}, thParams = THandleParams {blockSize, serviceAuth}} nm nonce_ tOut pKey entId cmd =
  ExceptT $ uncurry sendRecv =<< mkTransmission_ c nonce_ (entId, pKey, cmd)
  where
    -- two separate "atomically" needed to avoid blocking
@@ -1334,9 +1362,7 @@ sendProtocolCommand_ c@ProtocolClient {client_ = PClient {sndQ}, thParams = THan
            nonBlockingWriteTBQueue sndQ (Just r, s)
            response <$> getResponse c nm tOut r
        where
-          s
-            | batch = tEncodeBatch1 serviceAuth t
-            | otherwise = tEncode serviceAuth t
+          s = tEncodeBatch1 serviceAuth t

 nonBlockingWriteTBQueue :: TBQueue a -> a -> IO ()
 nonBlockingWriteTBQueue q x = do
@@ -47,6 +47,7 @@ import Crypto.Random (ChaChaDRG)
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.Constraint (Dict (..))
+import Data.Functor (($>))
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.List.NonEmpty as L
 import Data.Map.Strict (Map)
@@ -106,7 +107,7 @@ data SMPClientAgentConfig = SMPClientAgentConfig
  { smpCfg :: ProtocolClientConfig SMPVersion,
    reconnectInterval :: RetryInterval,
    persistErrorInterval :: NominalDiffTime,
-    msgQSize :: Natural,
+    msgQSize :: Maybe Natural,
    agentQSize :: Natural,
    agentSubsBatchSize :: Int,
    ownServerDomains :: [ByteString]
@@ -123,7 +124,7 @@ defaultSMPClientAgentConfig =
            maxInterval = 10 * second
          },
      persistErrorInterval = 30, -- seconds
-      msgQSize = 2048,
+      msgQSize = Just 2048,
      agentQSize = 2048,
      agentSubsBatchSize = 1360,
      ownServerDomains = []
@@ -137,7 +138,7 @@ data SMPClientAgent p = SMPClientAgent
    dbService :: Maybe DBService,
    active :: TVar Bool,
    startedAt :: UTCTime,
-    msgQ :: TBQueue (ServerTransmissionBatch SMPVersion ErrorType BrokerMsg),
+    msgQ :: Maybe (TBQueue (ServerTransmissionBatch SMPVersion ErrorType BrokerMsg)),
    agentQ :: TBQueue SMPClientAgentEvent,
    randomDrg :: TVar ChaChaDRG,
    smpClients :: TMap SMPServer SMPClientVar,
@@ -161,7 +162,8 @@ newSMPClientAgent :: SParty p -> SMPClientAgentConfig -> Maybe DBService -> TVar
 newSMPClientAgent agentParty agentCfg@SMPClientAgentConfig {msgQSize, agentQSize} dbService randomDrg = do
  active <- newTVarIO True
  startedAt <- getCurrentTime
-  msgQ <- newTBQueueIO msgQSize
+  -- Only subscribing agents receive server transmissions, should not be created until processed to prevent deadlock.
+  msgQ <- mapM newTBQueueIO msgQSize
  agentQ <- newTBQueueIO agentQSize
  smpClients <- TM.emptyIO
  smpSessions <- TM.emptyIO
@@ -204,11 +206,8 @@ getSMPServerClient' ca srv = snd <$> getSMPServerClient'' ca srv
 getSMPServerClient'' :: SMPClientAgent p -> SMPServer -> ExceptT SMPClientError IO (OwnServer, SMPClient)
 getSMPServerClient'' ca@SMPClientAgent {agentCfg, smpClients, smpSessions, workerSeq} srv = do
  ts <- liftIO getCurrentTime
-  atomically (getClientVar ts) >>= either (ExceptT . newSMPClient) waitForSMPClient
+  withGetSessVar workerSeq srv smpClients ts (ExceptT . newSMPClient) waitForSMPClient
  where
-    getClientVar :: UTCTime -> STM (Either SMPClientVar SMPClientVar)
-    getClientVar = getSessVar workerSeq srv smpClients
-
    waitForSMPClient :: SMPClientVar -> ExceptT SMPClientError IO (OwnServer, SMPClient)
    waitForSMPClient v = do
      let ProtocolClientConfig {networkConfig = NetworkConfig {tcpConnectTimeout}} = smpCfg agentCfg
@@ -266,7 +265,7 @@ connectClient ca@SMPClientAgent {agentCfg, dbService, smpClients, smpSessions, m
  Nothing -> getClient cfg
  where
    cfg = smpCfg agentCfg
-    getClient cfg' = getProtocolClient randomDrg NRMBackground (1, srv, Nothing) cfg' [] (Just msgQ) startedAt clientDisconnected
+    getClient cfg' = getProtocolClient randomDrg NRMBackground (1, srv, Nothing) cfg' [] msgQ startedAt clientDisconnected

    clientDisconnected :: SMPClient -> IO ()
    clientDisconnected smp = do
@@ -324,12 +323,16 @@ reconnectClient ca@SMPClientAgent {active, agentCfg, smpSubWorkers, workerSeq} s
        (Just <$> getSessVar workerSeq srv smpSubWorkers ts)
    newSubWorker :: SessionVar (Async ()) -> IO ()
    newSubWorker v = do
-      a <- async $ void (E.try @E.SomeException runSubWorker) >> atomically (cleanup v)
+      a <- async $ void $ E.try @E.SomeException $ runSubWorker v
      atomically $ putTMVar (sessionVar v) a
-    runSubWorker =
+    runSubWorker v =
      withRetryInterval (reconnectInterval agentCfg) $ \_ loop -> do
-        subs <- getPending TM.lookupIO readTVarIO
-        unless (noPending subs) $ whenM (readTVarIO active) $ do
+        subs_ <- atomically $ do                                                                                                                            
+          s <- getPending TM.lookup readTVar                                                                                                                
+          if noPending s                                                                                                                                    
+            then cleanup v $> Nothing                                                                                                                       
+            else pure $ Just s                                                                                                                              
+        forM_ subs_ $ \subs -> whenM (readTVarIO active) $ do  
          void $ netTimeoutInt tcpConnectTimeout NRMBackground `timeout` runExceptT (reconnectSMPClient ca srv subs)
          loop
    ProtocolClientConfig {networkConfig = NetworkConfig {tcpConnectTimeout}} = smpCfg agentCfg
@@ -7,6 +7,9 @@ module Simplex.Messaging.Compression
    compressionLevel,
    compress1,
    decompress1,
+    limitDecompress1,
+    limitDecompress',
+    decompressedSize,
  ) where

 import qualified Codec.Compression.Zstd as Z1
@@ -42,12 +45,28 @@ compress1 bs
  | B.length bs <= maxLengthPassthrough = Passthrough bs
  | otherwise = Compressed . Large $ Z1.compress compressionLevel bs

-decompress1 :: Int -> Compressed -> Either String ByteString
-decompress1 limit = \case
+decompressedSize :: Compressed -> Maybe Int
+decompressedSize = \case
+  Passthrough bs -> Just $ B.length bs
+  Compressed (Large bs) -> Z1.decompressedSize bs
+
+decompress1 :: Compressed -> Either String ByteString
+decompress1 = \case
  Passthrough bs -> Right bs
-  Compressed (Large bs) -> case Z1.decompressedSize bs of
-    Just sz | sz <= limit -> case Z1.decompress bs of
-      Z1.Error e -> Left e
-      Z1.Skip -> Right mempty
-      Z1.Decompress bs' -> Right bs'
-    _ -> Left $ "compressed size not specified or exceeds " <> show limit
+  Compressed (Large bs) -> decompress_ bs
+
+limitDecompress1 :: Int -> Compressed -> Either String ByteString
+limitDecompress1 limit = \case
+  Passthrough bs -> Right bs
+  Compressed (Large bs) -> limitDecompress' limit bs
+
+limitDecompress' :: Int -> ByteString -> Either String ByteString
+limitDecompress' limit bs = case Z1.decompressedSize bs of
+  Just sz | sz <= limit -> decompress_ bs
+  _ -> Left $ "compressed size not specified or exceeds " <> show limit
+
+decompress_ :: ByteString -> Either String ByteString
+decompress_ bs = case Z1.decompress bs of
+  Z1.Error e -> Left e
+  Z1.Skip -> Right mempty
+  Z1.Decompress bs' -> Right bs'
@@ -61,6 +61,7 @@ module Simplex.Messaging.Crypto
    APublicAuthKey (..),
    CryptoPublicKey (..),
    CryptoPrivateKey (..),
+    StoredPrivateKey (..),
    AAuthKeyPair,
    KeyPair,
    KeyPairX25519,
@@ -233,7 +234,7 @@ import qualified Data.Attoparsec.ByteString.Char8 as A
 import Data.Bifunctor (bimap, first)
 import Data.ByteArray (ByteArrayAccess)
 import qualified Data.ByteArray as BA
-import Data.ByteString.Base64 (decode, encode)
+import Data.ByteString.Base64 (decode)
 import qualified Data.ByteString.Base64.URL as U
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
@@ -342,8 +343,17 @@ deriving instance Eq (PrivateKey a)

 deriving instance Show (PrivateKey a)

-- Do not enable, to avoid leaking key data
-- instance StrEncoding (PrivateKey Ed25519) where
+-- Do not enable, to avoid leaking key data, use StoredPrivateKey instead
+-- instance StrEncoding (PrivateKey a) where
+
+newtype StoredPrivateKey a = StoredPrivateKey {unStored :: PrivateKey a}
+  deriving (Show)
+
+instance AlgorithmI a => StrEncoding (StoredPrivateKey a) where
+  strEncode = strEncode . encodePrivKey . unStored
+  {-# INLINE strEncode #-}
+  strDecode = fmap StoredPrivateKey . decodePrivKey
+  {-# INLINE strDecode #-}

 -- Used in notification store log
 instance StrEncoding (PrivateKey X25519) where
@@ -808,17 +818,22 @@ data ASignature
 deriving instance Show ASignature

 class CryptoSignature s where
-  serializeSignature :: s -> ByteString
-  serializeSignature = encode . signatureBytes
  signatureBytes :: s -> ByteString
  decodeSignature :: ByteString -> Either String s

 instance CryptoSignature (Signature s) => StrEncoding (Signature s) where
-  strEncode = serializeSignature
+  strEncode = strEncode . signatureBytes
  {-# INLINE strEncode #-}
  strDecode = decodeSignature
  {-# INLINE strDecode #-}

+instance CryptoSignature (Signature s) => ToJSON (Signature s) where
+  toJSON = strToJSON
+  toEncoding = strToJEncoding
+
+instance CryptoSignature (Signature s) => FromJSON (Signature s) where
+  parseJSON = strParseJSON "Signature"
+
 instance CryptoSignature (Signature s) => Encoding (Signature s) where
  smpEncode = smpEncode . signatureBytes
  {-# INLINE smpEncode #-}
@@ -0,0 +1,302 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE KindSignatures #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+
+-- | FFI bindings to libbbs (BBS+ signatures over BLS12-381, SHA-256 suite).
+-- Values parsed from untrusted input are length-validated; see FixedBS and the
+-- BBSProof StrEncoding instance.
+module Simplex.Messaging.Crypto.BBS
+  ( BBSSecretKey (..),
+    BBSPublicKey (..),
+    BBSKeyPair,
+    BBSSignature (..),
+    BBSProof (..),
+    BBSHeader (..),
+    BBSPresHeader (..),
+    bbsKeyGen,
+    bbsPublicKey,
+    bbsSign,
+    bbsVerify,
+    bbsProofGen,
+    bbsProofVerify,
+  ) where
+
+import Data.Aeson (FromJSON, ToJSON)
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as B
+import qualified Data.ByteString.Unsafe as BU
+import Data.Proxy (Proxy (..))
+import Foreign
+import Foreign.C
+import GHC.TypeLits (KnownNat, KnownSymbol, Nat, Symbol, natVal, symbolVal)
+import Simplex.Messaging.Encoding.String
+import System.IO.Unsafe (unsafePerformIO)
+
+-- Note: the data constructors below are unchecked escape hatches for trusted,
+-- internally-produced values (e.g. keygen output). Any value parsed from
+-- untrusted input (StrEncoding / FromJSON) is length-validated — see FixedBS
+-- and the BBSProof StrEncoding instance.
+
+newtype BBSSecretKey = BBSSecretKey ByteString
+  deriving newtype (Eq, Show)
+  deriving (StrEncoding) via (FixedBS "BBSSecretKey" 32)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSSecretKey" BBSSecretKey)
+
+newtype BBSPublicKey = BBSPublicKey ByteString
+  deriving newtype (Eq, Show)
+  deriving (StrEncoding) via (FixedBS "BBSPublicKey" 96)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSPublicKey" BBSPublicKey)
+
+type BBSKeyPair = (BBSPublicKey, BBSSecretKey)
+
+newtype BBSSignature = BBSSignature ByteString
+  deriving newtype (Eq, Show)
+  deriving (StrEncoding) via (FixedBS "BBSSignature" 80)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSSignature" BBSSignature)
+
+newtype BBSProof = BBSProof ByteString
+  deriving newtype (Eq, Show)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSProof" BBSProof)
+
+newtype BBSHeader = BBSHeader ByteString
+  deriving newtype (Eq, Show, StrEncoding)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSHeader" BBSHeader)
+
+newtype BBSPresHeader = BBSPresHeader ByteString
+  deriving newtype (Eq, Show, StrEncoding)
+  deriving (ToJSON, FromJSON) via (StrJSON "BBSPresHeader" BBSPresHeader)
+
+-- | A ByteString validated to be exactly @n@ bytes when parsed via StrEncoding
+-- (and the JSON derived from it). Local to BBS, where every key/signature is a
+-- fixed size; @name@ appears in the decode error only.
+newtype FixedBS (name :: Symbol) (n :: Nat) = FixedBS ByteString
+
+instance forall name n. (KnownSymbol name, KnownNat n) => StrEncoding (FixedBS name n) where
+  strEncode (FixedBS bs) = strEncode bs
+  strP = do
+    bs <- base64urlP
+    let n = fromIntegral (natVal (Proxy :: Proxy n))
+    if B.length bs == n
+      then pure (FixedBS bs)
+      else fail $ symbolVal (Proxy :: Proxy name) <> ": expected " <> show n <> " bytes, got " <> show (B.length bs)
+
+-- Constants
+
+bbsSkLen, bbsPkLen, bbsSigLen, bbsProofBaseLen, bbsProofUdElemLen :: Int
+bbsSkLen = 32
+bbsPkLen = 96
+bbsSigLen = 80
+bbsProofBaseLen = 272
+bbsProofUdElemLen = 32
+
+bbsProofLen :: Int -> Int
+bbsProofLen numUndisclosed = bbsProofBaseLen + numUndisclosed * bbsProofUdElemLen
+
+-- | A proof is @bbsProofBaseLen + 32 * numUndisclosed@ bytes; reject anything else.
+instance StrEncoding BBSProof where
+  strEncode (BBSProof bs) = strEncode bs
+  strP = do
+    bs <- base64urlP
+    let len = B.length bs
+    if len >= bbsProofBaseLen && (len - bbsProofBaseLen) `mod` bbsProofUdElemLen == 0
+      then pure (BBSProof bs)
+      else fail $ "BBS: invalid proof length " <> show len
+
+-- FFI
+
+data BBS_Ciphersuite
+
+foreign import ccall "bbs_keygen_full"
+  c_bbs_keygen_full :: Ptr BBS_Ciphersuite -> Ptr Word8 -> Ptr Word8 -> IO CInt
+
+foreign import ccall "bbs_sk_to_pk"
+  c_bbs_sk_to_pk :: Ptr BBS_Ciphersuite -> Ptr Word8 -> Ptr Word8 -> IO CInt
+
+foreign import ccall "bbs_sign"
+  c_bbs_sign ::
+    Ptr BBS_Ciphersuite ->
+    Ptr Word8 -> Ptr Word8 -> Ptr Word8 ->
+    Ptr Word8 -> CSize ->
+    CSize -> Ptr (Ptr Word8) -> Ptr CSize ->
+    IO CInt
+
+foreign import ccall "bbs_verify"
+  c_bbs_verify ::
+    Ptr BBS_Ciphersuite ->
+    Ptr Word8 -> Ptr Word8 ->
+    Ptr Word8 -> CSize ->
+    CSize -> Ptr (Ptr Word8) -> Ptr CSize ->
+    IO CInt
+
+foreign import ccall "bbs_proof_gen"
+  c_bbs_proof_gen ::
+    Ptr BBS_Ciphersuite ->
+    Ptr Word8 -> Ptr Word8 -> Ptr Word8 ->
+    Ptr Word8 -> CSize ->
+    Ptr Word8 -> CSize ->
+    Ptr CSize -> CSize ->
+    CSize -> Ptr (Ptr Word8) -> Ptr CSize ->
+    IO CInt
+
+foreign import ccall "bbs_proof_verify"
+  c_bbs_proof_verify ::
+    Ptr BBS_Ciphersuite ->
+    Ptr Word8 ->
+    Ptr Word8 -> CSize ->
+    Ptr Word8 -> CSize ->
+    Ptr Word8 -> CSize ->
+    Ptr CSize -> CSize ->
+    CSize -> Ptr (Ptr Word8) -> Ptr CSize ->
+    IO CInt
+
+foreign import ccall "&bbs_sha256_ciphersuite"
+  c_bbs_sha256_ciphersuite :: Ptr (Ptr BBS_Ciphersuite)
+
+-- The ciphersuite is a static const pointer in libbbs; read it once.
+ciphersuite :: Ptr BBS_Ciphersuite
+ciphersuite = unsafePerformIO $ peek c_bbs_sha256_ciphersuite
+{-# NOINLINE ciphersuite #-}
+
+-- Helpers
+
+withBS :: ByteString -> (Ptr Word8 -> CSize -> IO a) -> IO a
+withBS bs f = BU.unsafeUseAsCStringLen bs $ \(p, l) -> f (castPtr p) (fromIntegral l)
+
+packPtr :: Ptr Word8 -> Int -> IO ByteString
+packPtr ptr len = B.packCStringLen (castPtr ptr, len)
+
+-- Marshals a list of messages into parallel pointer/length arrays. Each
+-- ByteString is held alive (via nested unsafeUseAsCStringLen) until @f@ returns,
+-- so the C callee never sees a pointer to freed memory.
+withMessages :: [ByteString] -> (Ptr (Ptr Word8) -> Ptr CSize -> CSize -> IO a) -> IO a
+withMessages msgs f = go msgs []
+  where
+    go [] acc =
+      let cstrs = reverse acc
+       in withArray (map fst cstrs) $ \msgsPtr ->
+            withArray (map snd cstrs) $ \lensPtr ->
+              f msgsPtr lensPtr (fromIntegral $ length cstrs)
+    go (m : ms) acc =
+      BU.unsafeUseAsCStringLen m $ \(p, l) ->
+        go ms ((castPtr p :: Ptr Word8, fromIntegral l :: CSize) : acc)
+
+withIndexes :: [Int] -> (Ptr CSize -> CSize -> IO a) -> IO a
+withIndexes idxs f =
+  withArrayLen (map fromIntegral idxs :: [CSize]) $ \n ptr -> f ptr (fromIntegral n)
+
+-- libbbs expects disclosed indexes strictly ascending and in [0, total). This
+-- both matches the spec and guarantees the output-buffer size we compute matches
+-- what libbbs writes (no out-of-bounds write from a bad index list).
+ascendingInRange :: [Int] -> Int -> Bool
+ascendingInRange idxs total =
+  all (\i -> i >= 0 && i < total) idxs && and (zipWith (<) idxs (drop 1 idxs))
+
+-- Public API
+
+bbsKeyGen :: IO (Either String BBSKeyPair)
+bbsKeyGen =
+  allocaBytes bbsSkLen $ \skPtr ->
+    allocaBytes bbsPkLen $ \pkPtr -> do
+      rc <- c_bbs_keygen_full ciphersuite skPtr pkPtr
+      if rc /= 0
+        then pure $ Left "bbsKeyGen failed"
+        else do
+          sk <- packPtr skPtr bbsSkLen
+          pk <- packPtr pkPtr bbsPkLen
+          pure $ Right (BBSPublicKey pk, BBSSecretKey sk)
+
+bbsPublicKey :: BBSSecretKey -> IO (Either String BBSPublicKey)
+bbsPublicKey (BBSSecretKey sk) =
+  allocaBytes bbsPkLen $ \pkPtr ->
+    withBS sk $ \skPtr _ -> do
+      rc <- c_bbs_sk_to_pk ciphersuite skPtr pkPtr
+      if rc /= 0
+        then pure $ Left "bbsPublicKey failed"
+        else Right . BBSPublicKey <$> packPtr pkPtr bbsPkLen
+
+bbsSign ::
+  BBSSecretKey ->
+  BBSHeader ->
+  [ByteString] ->
+  IO (Either String BBSSignature)
+bbsSign secret@(BBSSecretKey sk) (BBSHeader header) msgs =
+  bbsPublicKey secret >>= either (pure . Left) sign'
+  where
+    sign' (BBSPublicKey pk) =
+      allocaBytes bbsSigLen $ \sigPtr ->
+        withBS sk $ \skPtr _ ->
+          withBS pk $ \pkPtr _ ->
+            withBS header $ \hdrPtr hdrLen ->
+              withMessages msgs $ \msgsPtr lensPtr n -> do
+                rc <- c_bbs_sign ciphersuite skPtr pkPtr sigPtr hdrPtr hdrLen n msgsPtr lensPtr
+                if rc /= 0
+                  then pure $ Left "bbsSign failed"
+                  else Right . BBSSignature <$> packPtr sigPtr bbsSigLen
+
+bbsVerify ::
+  BBSPublicKey ->
+  BBSSignature ->
+  BBSHeader ->
+  [ByteString] ->
+  IO Bool
+bbsVerify (BBSPublicKey pk) (BBSSignature sig) (BBSHeader header) msgs =
+  withBS pk $ \pkPtr _ ->
+    withBS sig $ \sigPtr _ ->
+      withBS header $ \hdrPtr hdrLen ->
+        withMessages msgs $ \msgsPtr lensPtr n -> do
+          rc <- c_bbs_verify ciphersuite pkPtr sigPtr hdrPtr hdrLen n msgsPtr lensPtr
+          pure (rc == 0)
+
+bbsProofGen ::
+  BBSPublicKey ->
+  BBSSignature ->
+  BBSHeader ->
+  BBSPresHeader ->
+  [Int] ->
+  [ByteString] ->
+  IO (Either String BBSProof)
+bbsProofGen (BBSPublicKey pk) (BBSSignature sig) (BBSHeader header) (BBSPresHeader ph) disclosedIdxs msgs
+  | not (ascendingInRange disclosedIdxs (length msgs)) = pure $ Left "bbsProofGen: invalid disclosed indexes"
+  | otherwise =
+  allocaBytes proofSz $ \proofPtr ->
+    withBS pk $ \pkPtr _ ->
+      withBS sig $ \sigPtr _ ->
+        withBS header $ \hdrPtr hdrLen ->
+          withBS ph $ \phPtr phLen ->
+            withIndexes disclosedIdxs $ \idxsPtr idxsLen ->
+              withMessages msgs $ \msgsPtr lensPtr n -> do
+                rc <- c_bbs_proof_gen ciphersuite pkPtr sigPtr proofPtr hdrPtr hdrLen phPtr phLen idxsPtr idxsLen n msgsPtr lensPtr
+                if rc /= 0
+                  then pure $ Left "bbsProofGen failed"
+                  else Right . BBSProof <$> packPtr proofPtr proofSz
+  where
+    numUndisclosed = length msgs - length disclosedIdxs
+    proofSz = bbsProofLen numUndisclosed
+
+bbsProofVerify ::
+  BBSPublicKey ->
+  BBSProof ->
+  BBSHeader ->
+  BBSPresHeader ->
+  [Int] ->
+  Int ->
+  [ByteString] ->
+  IO Bool
+bbsProofVerify (BBSPublicKey pk) (BBSProof proof) (BBSHeader header) (BBSPresHeader ph) disclosedIdxs numMessages disclosedMsgs
+  | numMessages < 0 = pure False
+  | length disclosedIdxs /= length disclosedMsgs = pure False
+  | not (ascendingInRange disclosedIdxs numMessages) = pure False
+  | B.length proof /= bbsProofLen (numMessages - length disclosedIdxs) = pure False
+  | otherwise =
+  withBS pk $ \pkPtr _ ->
+    withBS proof $ \proofPtr proofLen ->
+      withBS header $ \hdrPtr hdrLen ->
+        withBS ph $ \phPtr phLen ->
+          withIndexes disclosedIdxs $ \idxsPtr idxsLen ->
+            withMessages disclosedMsgs $ \msgsPtr lensPtr _ -> do
+              rc <- c_bbs_proof_verify ciphersuite pkPtr proofPtr proofLen hdrPtr hdrLen phPtr phLen idxsPtr idxsLen (fromIntegral numMessages) msgsPtr lensPtr
+              pure (rc == 0)
@@ -37,6 +37,7 @@ module Simplex.Messaging.Crypto.Ratchet
    AUseKEM (..),
    RatchetKEMState (..),
    SRatchetKEMState (..),
+    RatchetKEMStateI (..),
    RcvPrivRKEMParams,
    APrivRKEMParams (..),
    RcvE2ERatchetParamsUri,
@@ -45,12 +46,11 @@ module Simplex.Messaging.Crypto.Ratchet
    AE2ERatchetParams (..),
    E2ERatchetParamsUri (..),
    E2ERatchetParams (..),
+    RcvE2EPrivRatchetParams,
    VersionE2E,
    VersionRangeE2E,
    pattern VersionE2E,
    RatchetVersions (..),
-    kdfX3DHE2EEncryptVersion,
-    pqRatchetE2EEncryptVersion,
    currentE2EEncryptVersion,
    supportedE2EEncryptVRange,
    generateRcvE2EParams,
@@ -85,8 +85,6 @@ module Simplex.Messaging.Crypto.Ratchet
    RatchetKey (..),
    fullHeaderLen,
    applySMDiff,
-    encodeMsgHeader,
-    msgHeaderP,
  )
 where

@@ -100,7 +98,6 @@ import Crypto.Random (ChaChaDRG)
 import Data.Aeson (FromJSON (..), ToJSON (..))
 import qualified Data.Aeson as J
 import qualified Data.Aeson.TH as JQ
-import Data.Attoparsec.ByteString (Parser, peekWord8')
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import qualified Data.ByteArray as BA
 import Data.ByteString.Char8 (ByteString)
@@ -130,6 +127,7 @@ import UnliftIO.STM
 -- e2e encryption headers version history:
 -- 1 - binary protocol encoding (1/1/2022)
 -- 2 - use KDF in x3dh (10/20/2022)
+-- 3 - PQDR (3/14/2024)

 data E2EVersion

@@ -142,17 +140,17 @@ type VersionRangeE2E = VersionRange E2EVersion
 pattern VersionE2E :: Word16 -> VersionE2E
 pattern VersionE2E v = Version v

-kdfX3DHE2EEncryptVersion :: VersionE2E
-kdfX3DHE2EEncryptVersion = VersionE2E 2
+_pqRatchetE2EEncryptVersion :: VersionE2E
+_pqRatchetE2EEncryptVersion = VersionE2E 3

-pqRatchetE2EEncryptVersion :: VersionE2E
-pqRatchetE2EEncryptVersion = VersionE2E 3
+minSupportedE2EEncryptVersion :: VersionE2E
+minSupportedE2EEncryptVersion = _pqRatchetE2EEncryptVersion

 currentE2EEncryptVersion :: VersionE2E
 currentE2EEncryptVersion = VersionE2E 3

 supportedE2EEncryptVRange :: VersionRangeE2E
-supportedE2EEncryptVRange = mkVersionRange kdfX3DHE2EEncryptVersion currentE2EEncryptVersion
+supportedE2EEncryptVRange = mkVersionRange minSupportedE2EEncryptVersion currentE2EEncryptVersion

 data RatchetKEMState
  = RKSProposed -- only KEM encapsulation key
@@ -236,9 +234,7 @@ data AnyE2ERatchetParams
 deriving instance Show AnyE2ERatchetParams

 instance (RatchetKEMStateI s, AlgorithmI a) => Encoding (E2ERatchetParams s a) where
-  smpEncode (E2ERatchetParams v k1 k2 kem_)
-    | v >= pqRatchetE2EEncryptVersion = smpEncode (v, k1, k2, kem_)
-    | otherwise = smpEncode (v, k1, k2)
+  smpEncode (E2ERatchetParams v k1 k2 kem_) = smpEncode (v, k1, k2, kem_)
  smpP = toParams <$?> smpP
    where
      toParams :: AE2ERatchetParams a -> Either String (E2ERatchetParams s a)
@@ -259,14 +255,9 @@ instance Encoding AnyE2ERatchetParams where
    case testEquality a a' of
      Nothing -> fail "bad e2e params: different key algorithms"
      Just Refl ->
-        kemP v >>= \case
+        smpP >>= \case
          Just (ARKP s kem) -> pure $ AnyE2ERatchetParams s a $ E2ERatchetParams v k1 k2 (Just kem)
          Nothing -> pure $ AnyE2ERatchetParams SRKSProposed a $ E2ERatchetParams v k1 k2 Nothing
-    where
-      kemP :: VersionE2E -> Parser (Maybe ARKEMParams)
-      kemP v
-        | v >= pqRatchetE2EEncryptVersion = smpP
-        | otherwise = pure Nothing

 instance VersionI E2EVersion (E2ERatchetParams s a) where
  type VersionRangeT E2EVersion (E2ERatchetParams s a) = E2ERatchetParamsUri s a
@@ -305,11 +296,10 @@ instance (RatchetKEMStateI s, AlgorithmI a) => StrEncoding (E2ERatchetParamsUri
      [("v", strEncode vs), ("x3dh", strEncodeList [key1, key2])]
        <> maybe [] encodeKem kem_
    where
-      encodeKem kem
-        | maxVersion vs < pqRatchetE2EEncryptVersion = []
-        | otherwise = case kem of
-            RKParamsProposed k -> [("kem_key", strEncode k)]
-            RKParamsAccepted ct k -> [("kem_ct", strEncode ct), ("kem_key", strEncode k)]
+      encodeKem :: RKEMParams s -> [(ByteString, ByteString)]
+      encodeKem kem  = case kem of
+        RKParamsProposed k -> [("kem_key", strEncode k)]
+        RKParamsAccepted ct k -> [("kem_ct", strEncode ct), ("kem_key", strEncode k)]
  strP = toE2ERatchetParamsUri <$?> strP
  {-# INLINE strP #-}

@@ -326,25 +316,26 @@ instance StrEncoding AnyE2ERatchetParamsUri where
  strEncode (AnyE2ERatchetParamsUri _ _ ps) = strEncode ps
  strP = do
    query <- strP
-    vr :: VersionRangeE2E <- queryParam "v" query
+    vr :: VersionRangeE2E <- adjustE2EVRange <$> queryParam "v" query
    keys <- L.toList <$> queryParam "x3dh" query
    case keys of
      [APublicDhKey a k1, APublicDhKey a' k2] -> case testEquality a a' of
        Nothing -> fail "bad e2e params: different key algorithms"
        Just Refl ->
-          kemP vr query >>= \case
+          kemP query >>= \case
            Just (ARKP s kem) -> pure $ AnyE2ERatchetParamsUri s a $ E2ERatchetParamsUri vr k1 k2 (Just kem)
            Nothing -> pure $ AnyE2ERatchetParamsUri SRKSProposed a $ E2ERatchetParamsUri vr k1 k2 Nothing
      _ -> fail "bad e2e params"
    where
-      kemP vr query
-        | maxVersion vr >= pqRatchetE2EEncryptVersion =
-            queryParam_ "kem_key" query
-              $>>= \k -> Just . kemParams k <$> queryParam_ "kem_ct" query
-        | otherwise = pure Nothing
+      kemP query =
+        queryParam_ "kem_key" query
+          $>>= \k -> Just . kemParams k <$> queryParam_ "kem_ct" query
      kemParams k = \case
        Nothing -> ARKP SRKSProposed $ RKParamsProposed k
        Just ct -> ARKP SRKSAccepted $ RKParamsAccepted ct k
+      adjustE2EVRange vr =
+        let v = max minSupportedE2EEncryptVersion $ minVersion vr
+        in fromMaybe vr $ safeVersionRange v (max v $ maxVersion vr)

 instance (RatchetKEMStateI s, AlgorithmI a) => Encoding (E2ERatchetParamsUri s a) where
  smpEncode (E2ERatchetParamsUri vr k1 k2 kem_) = smpEncode (vr, k1, k2, kem_)
@@ -403,40 +394,44 @@ instance RatchetKEMStateI s => ToField (PrivRKEMParams s) where toField = toFiel

 instance (Typeable s, RatchetKEMStateI s) => FromField (PrivRKEMParams s) where fromField = blobFieldDecoder smpDecode

+type E2EPrivRatchetParams s a = (PrivateKey a, PrivateKey a, Maybe (PrivRKEMParams s))\
+
+type RcvE2EPrivRatchetParams a = E2EPrivRatchetParams 'RKSProposed a
+
+type AE2EPrivRatchetParams a = (PrivateKey a, PrivateKey a, Maybe APrivRKEMParams)
+
 data UseKEM (s :: RatchetKEMState) where
  ProposeKEM :: UseKEM 'RKSProposed
  AcceptKEM :: KEMPublicKey -> UseKEM 'RKSAccepted

 data AUseKEM = forall s. RatchetKEMStateI s => AUseKEM (SRatchetKEMState s) (UseKEM s)

-mkRcvE2ERatchetParams :: VersionE2E -> (PrivateKey a, PrivateKey a, Maybe RcvPrivRKEMParams) -> RcvE2ERatchetParams a
+mkRcvE2ERatchetParams :: VersionE2E -> RcvE2EPrivRatchetParams a -> RcvE2ERatchetParams a
 mkRcvE2ERatchetParams v (pk1, pk2, pKem) = E2ERatchetParams v (publicKey pk1) (publicKey pk2) (mkKem <$> pKem)
  where
    mkKem :: RcvPrivRKEMParams -> RcvRKEMParams
    mkKem (PrivateRKParamsProposed (k, _)) = RKParamsProposed k

-generateE2EParams :: forall s a. (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> Maybe (UseKEM s) -> IO (PrivateKey a, PrivateKey a, Maybe (PrivRKEMParams s), E2ERatchetParams s a)
+generateE2EParams :: forall s a. (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> Maybe (UseKEM s) -> IO (E2EPrivRatchetParams s a, E2ERatchetParams s a)
 generateE2EParams g v useKEM_ = do
  (k1, pk1) <- atomically $ generateKeyPair g
  (k2, pk2) <- atomically $ generateKeyPair g
  kems <- kemParams
-  pure (pk1, pk2, snd <$> kems, E2ERatchetParams v k1 k2 (fst <$> kems))
+  pure ((pk1, pk2, snd <$> kems), E2ERatchetParams v k1 k2 (fst <$> kems))
  where
    kemParams :: IO (Maybe (RKEMParams s, PrivRKEMParams s))
    kemParams = case useKEM_ of
-      Just useKem
-        | v >= pqRatchetE2EEncryptVersion ->
-            Just <$> do
-              ks@(k, _) <- sntrup761Keypair g
-              case useKem of
-                ProposeKEM -> pure (RKParamsProposed k, PrivateRKParamsProposed ks)
-                AcceptKEM k' -> do
-                  (ct, shared) <- sntrup761Enc g k'
-                  pure (RKParamsAccepted ct k, PrivateRKParamsAccepted ct shared ks)
-      _ -> pure Nothing
+      Just useKem -> Just <$> do
+        ks@(k, _) <- sntrup761Keypair g
+        case useKem of
+          ProposeKEM -> pure (RKParamsProposed k, PrivateRKParamsProposed ks)
+          AcceptKEM k' -> do
+            (ct, shared) <- sntrup761Enc g k'
+            pure (RKParamsAccepted ct k, PrivateRKParamsAccepted ct shared ks)
+      Nothing -> pure Nothing

 -- used by party initiating connection, Bob in double-ratchet spec
-generateRcvE2EParams :: (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> PQSupport -> IO (PrivateKey a, PrivateKey a, Maybe (PrivRKEMParams 'RKSProposed), E2ERatchetParams 'RKSProposed a)
+generateRcvE2EParams :: (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> PQSupport -> IO (RcvE2EPrivRatchetParams a, RcvE2ERatchetParams a)
 generateRcvE2EParams g v = generateE2EParams g v . proposeKEM_
  where
    proposeKEM_ :: PQSupport -> Maybe (UseKEM 'RKSProposed)
@@ -445,14 +440,14 @@ generateRcvE2EParams g v = generateE2EParams g v . proposeKEM_
      PQSupportOff -> Nothing

 -- used by party accepting connection, Alice in double-ratchet spec
-generateSndE2EParams :: forall a. (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> Maybe AUseKEM -> IO (PrivateKey a, PrivateKey a, Maybe APrivRKEMParams, AE2ERatchetParams a)
+generateSndE2EParams :: forall a. (AlgorithmI a, DhAlgorithm a) => TVar ChaChaDRG -> VersionE2E -> Maybe AUseKEM -> IO (AE2EPrivRatchetParams a, AE2ERatchetParams a)
 generateSndE2EParams g v = \case
  Nothing -> do
-    (pk1, pk2, _, e2eParams) <- generateE2EParams g v Nothing
-    pure (pk1, pk2, Nothing, AE2ERatchetParams SRKSProposed e2eParams)
+    ((pk1, pk2, _), e2eParams) <- generateE2EParams g v Nothing
+    pure ((pk1, pk2, Nothing), AE2ERatchetParams SRKSProposed e2eParams)
  Just (AUseKEM s useKEM) -> do
-    (pk1, pk2, pKem, e2eParams) <- generateE2EParams g v (Just useKEM)
-    pure (pk1, pk2, APRKP s <$> pKem, AE2ERatchetParams s e2eParams)
+    ((pk1, pk2, pKem), e2eParams) <- generateE2EParams g v (Just useKEM)
+    pure ((pk1, pk2, APRKP s <$> pKem), AE2ERatchetParams s e2eParams)

 data RatchetInitParams = RatchetInitParams
  { assocData :: Str,
@@ -464,32 +459,32 @@ data RatchetInitParams = RatchetInitParams
  deriving (Show)

 -- this is used by the peer joining the connection
-pqX3dhSnd :: DhAlgorithm a => PrivateKey a -> PrivateKey a -> Maybe APrivRKEMParams -> E2ERatchetParams 'RKSProposed a -> Either CryptoError (RatchetInitParams, Maybe KEMKeyPair)
+pqX3dhSnd :: DhAlgorithm a => AE2EPrivRatchetParams a -> E2ERatchetParams 'RKSProposed a -> Either CryptoError (RatchetInitParams, Maybe KEMKeyPair)
 --        3. replied       2. received
-pqX3dhSnd spk1 spk2 spKem_ (E2ERatchetParams v rk1 rk2 rKem_) = do
+pqX3dhSnd (spk1, spk2, spKem_) (E2ERatchetParams _ rk1 rk2 rKem_) = do
  (ks_, kem_) <- sndPq
  let initParams = pqX3dh (publicKey spk1, rk1) (dh' rk1 spk2) (dh' rk2 spk1) (dh' rk2 spk2) kem_
  pure (initParams, ks_)
  where
    sndPq :: Either CryptoError (Maybe KEMKeyPair, Maybe RatchetKEMAccepted)
    sndPq = case spKem_ of
-      Just (APRKP _ ps) | v >= pqRatchetE2EEncryptVersion -> case (ps, rKem_) of
+      Just (APRKP _ ps) -> case (ps, rKem_) of
        (PrivateRKParamsAccepted ct shared ks, Just (RKParamsProposed k)) -> Right (Just ks, Just $ RatchetKEMAccepted k shared ct)
        (PrivateRKParamsProposed ks, _) -> Right (Just ks, Nothing) -- both parties can send "proposal" in case of ratchet renegotiation
        _ -> Left CERatchetKEMState
-      _ -> Right (Nothing, Nothing)
+      Nothing -> Right (Nothing, Nothing)

 -- this is used by the peer that created new connection, after receiving the reply
-pqX3dhRcv :: forall s a. (RatchetKEMStateI s, DhAlgorithm a) => PrivateKey a -> PrivateKey a -> Maybe (PrivRKEMParams 'RKSProposed) -> E2ERatchetParams s a -> ExceptT CryptoError IO (RatchetInitParams, Maybe KEMKeyPair)
+pqX3dhRcv :: forall s a. (RatchetKEMStateI s, DhAlgorithm a) => RcvE2EPrivRatchetParams a -> E2ERatchetParams s a -> ExceptT CryptoError IO (RatchetInitParams, Maybe KEMKeyPair)
 --        1. sent          4. received in reply
-pqX3dhRcv rpk1 rpk2 rpKem_ (E2ERatchetParams v sk1 sk2 sKem_) = do
+pqX3dhRcv (rpk1, rpk2, rpKem_) (E2ERatchetParams _ sk1 sk2 sKem_) = do
  kem_ <- rcvPq
  let initParams = pqX3dh (sk1, publicKey rpk1) (dh' sk2 rpk1) (dh' sk1 rpk2) (dh' sk2 rpk2) (snd <$> kem_)
  pure (initParams, fst <$> kem_)
  where
    rcvPq :: ExceptT CryptoError IO (Maybe (KEMKeyPair, RatchetKEMAccepted))
    rcvPq = case sKem_ of
-      Just (RKParamsAccepted ct k') | v >= pqRatchetE2EEncryptVersion -> case rpKem_ of
+      Just (RKParamsAccepted ct k') -> case rpKem_ of
        Just (PrivateRKParamsProposed ks@(_, pk)) -> do
          shared <- liftIO $ sntrup761Dec ct pk
          pure $ Just (ks, RatchetKEMAccepted k' shared ct)
@@ -713,31 +708,22 @@ data MsgHeader a = MsgHeader
 -- to allow extension without increasing the size, the actual header length is:
 -- 69 = 2 (original size) + 2 + 1+56 (Curve448) + 4 + 4
 -- The exact size is 2288, added reserve
-paddedHeaderLen :: VersionE2E -> PQSupport -> Int
-paddedHeaderLen v = \case
-  PQSupportOn | v >= pqRatchetE2EEncryptVersion -> 2310
-  _ -> 88
+paddedHeaderLen :: PQSupport -> Int
+paddedHeaderLen = \case
+  PQSupportOn -> 2310
+  PQSupportOff -> 88

 -- only used in tests to validate correct padding
 -- (2 bytes - version size, 1 byte - header size)
-fullHeaderLen :: VersionE2E -> PQSupport -> Int
-fullHeaderLen v pq = 2 + 1 + paddedHeaderLen v pq + authTagSize + ivSize @AES256
+fullHeaderLen :: PQSupport -> Int
+fullHeaderLen pq = 2 + 1 + paddedHeaderLen pq + authTagSize + ivSize @AES256

-- pass the current version, as MsgHeader only includes the max supported version that can be different from the current
-encodeMsgHeader :: AlgorithmI a => VersionE2E -> MsgHeader a -> ByteString
-encodeMsgHeader v MsgHeader {msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs}
-  | v >= pqRatchetE2EEncryptVersion = smpEncode (msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs)
-  | otherwise = smpEncode (msgMaxVersion, msgDHRs, msgPN, msgNs)
-
-- pass the current version, as MsgHeader only includes the max supported version that can be different from the current
-msgHeaderP :: AlgorithmI a => VersionE2E -> Parser (MsgHeader a)
-msgHeaderP v = do
-  msgMaxVersion <- smpP
-  msgDHRs <- smpP
-  msgKEM <- if v >= pqRatchetE2EEncryptVersion then smpP else pure Nothing
-  msgPN <- smpP
-  msgNs <- smpP
-  pure MsgHeader {msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs}
+instance AlgorithmI a => Encoding (MsgHeader a) where
+  smpEncode MsgHeader {msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs} =
+    smpEncode (msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs)
+  smpP = do
+    (msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs) <- smpP
+    pure MsgHeader {msgMaxVersion, msgDHRs, msgKEM, msgPN, msgNs}

 data EncMessageHeader = EncMessageHeader
  { ehVersion :: VersionE2E, -- this is current ratchet version
@@ -749,26 +735,11 @@ data EncMessageHeader = EncMessageHeader
 -- this encoding depends on version in EncMessageHeader because it is "current" ratchet version
 instance Encoding EncMessageHeader where
  smpEncode EncMessageHeader {ehVersion, ehIV, ehAuthTag, ehBody} =
-    smpEncode (ehVersion, ehIV, ehAuthTag) <> encodeLarge ehVersion ehBody
+    smpEncode (ehVersion, ehIV, ehAuthTag, Large ehBody)
  smpP = do
-    (ehVersion, ehIV, ehAuthTag) <- smpP
-    ehBody <- largeP
+    (ehVersion, ehIV, ehAuthTag, Large ehBody) <- smpP
    pure EncMessageHeader {ehVersion, ehIV, ehAuthTag, ehBody}

-- the encoder always uses 2-byte lengths for the new version, even for short headers without PQ keys.
-encodeLarge :: VersionE2E -> ByteString -> ByteString
-encodeLarge v s
-  | v >= pqRatchetE2EEncryptVersion = smpEncode $ Large s
-  | otherwise = smpEncode s
-
-- This parser relies on the fact that header cannot be shorter than 32 bytes (it is ~69 bytes without PQ KEM),
-- therefore if the first byte is less or equal to 31 (x1F), then we have 2 byte-length limited to 8191.
-- This allows upgrading the current version in one message.
-largeP :: Parser ByteString
-largeP = do
-  len1 <- peekWord8'
-  if len1 < 32 then unLarge <$> smpP else smpP
-
 -- the header is length-prefixed to parse it as string and use as part of associated data for authenticated encryption
 data EncRatchetMessage = EncRatchetMessage
  { emHeader :: ByteString,
@@ -776,15 +747,12 @@ data EncRatchetMessage = EncRatchetMessage
    emBody :: ByteString
  }

-encodeEncRatchetMessage :: VersionE2E -> EncRatchetMessage -> ByteString
-encodeEncRatchetMessage v EncRatchetMessage {emHeader, emBody, emAuthTag} =
-  encodeLarge v emHeader <> smpEncode (emAuthTag, Tail emBody)
-
-encRatchetMessageP :: Parser EncRatchetMessage
-encRatchetMessageP = do
-  emHeader <- largeP
-  (emAuthTag, Tail emBody) <- smpP
-  pure EncRatchetMessage {emHeader, emBody, emAuthTag}
+instance Encoding EncRatchetMessage where
+  smpEncode EncRatchetMessage {emHeader, emBody, emAuthTag} =
+    smpEncode (Large emHeader, emAuthTag, Tail emBody)
+  smpP = do
+    (Large emHeader, emAuthTag, Tail emBody) <- smpP
+    pure EncRatchetMessage {emHeader, emBody, emAuthTag}

 newtype PQEncryption = PQEncryption {enablePQ :: Bool}
  deriving (Eq, Show)
@@ -833,15 +801,15 @@ pqEncToSupport (PQEncryption pq) = PQSupport pq
 pqSupportAnd :: PQSupport -> PQSupport -> PQSupport
 pqSupportAnd (PQSupport s1) (PQSupport s2) = PQSupport $ s1 && s2

-pqEnableSupport :: VersionE2E -> PQSupport -> PQEncryption -> PQSupport
-pqEnableSupport v (PQSupport sup) (PQEncryption enc) = PQSupport $ sup || (v >= pqRatchetE2EEncryptVersion && enc)
+pqEnableSupport :: PQSupport -> PQEncryption -> PQSupport
+pqEnableSupport (PQSupport sup) (PQEncryption enc) = PQSupport $ sup || enc

-replyKEM_ :: VersionE2E -> Maybe (RKEMParams 'RKSProposed) -> PQSupport -> Maybe AUseKEM
-replyKEM_ v kem_ = \case
-  PQSupportOn | v >= pqRatchetE2EEncryptVersion -> Just $ case kem_ of
+replyKEM_ :: Maybe (RKEMParams 'RKSProposed) -> PQSupport -> Maybe AUseKEM
+replyKEM_ kem_ = \case
+  PQSupportOn -> Just $ case kem_ of
    Just (RKParamsProposed k) -> AUseKEM SRKSAccepted $ AcceptKEM k
    Nothing -> AUseKEM SRKSProposed ProposeKEM
-  _ -> Nothing
+  PQSupportOff -> Nothing

 instance StrEncoding PQEncryption where
  strEncode pqMode
@@ -890,9 +858,9 @@ connPQEncryption = \case
  IKUsePQ -> PQSupportOn
  IKLinkPQ pq -> pq -- default for creating connection is IKLinkPQ PQEncOn

-joinContactInitialKeys :: Bool -> PQSupport -> InitialKeys
-joinContactInitialKeys pqCompatible = \case
-  PQSupportOn | pqCompatible -> IKUsePQ
+joinContactInitialKeys :: PQSupport -> InitialKeys
+joinContactInitialKeys = \case
+  PQSupportOn -> IKUsePQ
  pqEnc -> IKLinkPQ pqEnc

 rcCheckCanPad :: Int -> ByteString -> ExceptT CryptoError IO ()
@@ -908,14 +876,14 @@ rcEncryptHeader rc@Ratchet {rcSnd = Just sr@SndRatchet {rcCKs, rcHKs}, rcDHRs, r
      -- PQ encryption can be enabled or disabled
      rcEnableKEM' = fromMaybe rcEnableKEM pqEnc_
      -- support for PQ encryption (and therefore large headers/small envelopes) can only be enabled, it cannot be disabled
-      rcSupportKEM' = pqEnableSupport v rcSupportKEM rcEnableKEM'
+      rcSupportKEM' = pqEnableSupport rcSupportKEM rcEnableKEM'
      -- This sets max version to support PQ encryption.
      -- Current version upgrade happens when peer decrypts the message.
      -- TODO note that maxSupported will not downgrade here below current (v).
-      maxSupported' = max supportedE2EVersion $ if pqEnc_ == Just PQEncOn then pqRatchetE2EEncryptVersion else v
+      maxSupported' = max supportedE2EVersion $ if pqEnc_ == Just PQEncOn then minSupportedE2EEncryptVersion else v
      rcVersion' = rcVersion {maxSupported = maxSupported'}
  -- enc_header = HENCRYPT(state.HKs, header)
-  (ehAuthTag, ehBody) <- encryptAEAD rcHKs ehIV (paddedHeaderLen v rcSupportKEM') rcAD (msgHeader v maxSupported')
+  (ehAuthTag, ehBody) <- encryptAEAD rcHKs ehIV (paddedHeaderLen rcSupportKEM') rcAD (msgHeader maxSupported')
  -- return enc_header
  let emHeader = smpEncode EncMessageHeader {ehVersion = v, ehBody, ehAuthTag, ehIV}
      msgEncryptKey =
@@ -943,9 +911,8 @@ rcEncryptHeader rc@Ratchet {rcSnd = Just sr@SndRatchet {rcCKs, rcHKs}, rcDHRs, r
    --   pn = state.PN,
    --   n = state.Ns
    -- )
-    msgHeader v maxSupported' =
-      encodeMsgHeader
-        v
+    msgHeader maxSupported' =
+      smpEncode
        MsgHeader
          { msgMaxVersion = maxSupported',
            msgDHRs = publicKey rcDHRs,
@@ -968,11 +935,10 @@ data MsgEncryptKey a = MsgEncryptKey
  deriving (Show)

 rcEncryptMsg :: AlgorithmI a => MsgEncryptKey a -> Int -> ByteString -> ExceptT CryptoError IO ByteString
-rcEncryptMsg MsgEncryptKey {msgKey = MessageKey mk iv, msgRcAD, msgEncHeader, msgRcVersion = v} paddedMsgLen msg = do
+rcEncryptMsg MsgEncryptKey {msgKey = MessageKey mk iv, msgRcAD, msgEncHeader} paddedMsgLen msg = do
  -- return ENCRYPT(mk, plaintext, CONCAT(AD, enc_header))
  (emAuthTag, emBody) <- encryptAEAD mk iv paddedMsgLen (msgRcAD <> msgEncHeader) msg
-  let msg' = encodeEncRatchetMessage v EncRatchetMessage {emHeader = msgEncHeader, emBody, emAuthTag}
-  pure msg'
+  pure $ smpEncode EncRatchetMessage {emHeader = msgEncHeader, emBody, emAuthTag}

 data SkippedMessage a
  = SMMessage (DecryptResult a)
@@ -996,7 +962,7 @@ rcDecrypt ::
  ByteString ->
  ExceptT CryptoError IO (DecryptResult a)
 rcDecrypt g rc@Ratchet {rcRcv, rcAD = Str rcAD, rcVersion} rcMKSkipped msg' = do
-  encMsg@EncRatchetMessage {emHeader} <- parseE CryptoHeaderError encRatchetMessageP msg'
+  encMsg@EncRatchetMessage {emHeader} <- parseE CryptoHeaderError smpP msg'
  encHdr <- parseE CryptoHeaderError smpP emHeader
  -- plaintext = TrySkippedMessageKeysHE(state, enc_header, cipher-text, AD)
  decryptSkipped encHdr encMsg >>= \case
@@ -1041,7 +1007,7 @@ rcDecrypt g rc@Ratchet {rcRcv, rcAD = Str rcAD, rcVersion} rcMKSkipped msg' = do
        smkDiff :: SkippedMsgKeys -> SkippedMsgDiff
        smkDiff smks = if M.null smks then SMDNoChange else SMDAdd smks
        ratchetStep :: Ratchet a -> MsgHeader a -> ExceptT CryptoError IO (Ratchet a)
-        ratchetStep rc'@Ratchet {rcDHRs, rcRK, rcNHKs, rcNHKr, rcSupportKEM, rcVersion = rv} MsgHeader {msgDHRs, msgKEM} = do
+        ratchetStep rc'@Ratchet {rcDHRs, rcRK, rcNHKs, rcNHKr, rcSupportKEM} MsgHeader {msgDHRs, msgKEM} = do
          (kemSS, kemSS', rcKEM') <- pqRatchetStep rc' msgKEM
          -- state.DHRs = GENERATE_DH()
          (_, rcDHRs') <- atomically $ generateKeyPair @a g
@@ -1056,7 +1022,7 @@ rcDecrypt g rc@Ratchet {rcRcv, rcAD = Str rcAD, rcVersion} rcMKSkipped msg' = do
            rc'
              { rcDHRs = rcDHRs',
                rcKEM = rcKEM',
-                rcSupportKEM = pqEnableSupport (current rv) rcSupportKEM rcEnableKEM',
+                rcSupportKEM = pqEnableSupport rcSupportKEM rcEnableKEM',
                rcEnableKEM = rcEnableKEM',
                rcSndKEM = PQEncryption sndKEM,
                rcRcvKEM = PQEncryption rcvKEM,
@@ -1070,17 +1036,17 @@ rcDecrypt g rc@Ratchet {rcRcv, rcAD = Str rcAD, rcVersion} rcMKSkipped msg' = do
                rcNHKr = rcNHKr'
              }
        pqRatchetStep :: Ratchet a -> Maybe ARKEMParams -> ExceptT CryptoError IO (Maybe KEMSharedKey, Maybe KEMSharedKey, Maybe RatchetKEM)
-        pqRatchetStep Ratchet {rcKEM, rcEnableKEM = PQEncryption pqEnc, rcVersion = rv} = \case
+        pqRatchetStep Ratchet {rcKEM, rcEnableKEM = PQEncryption pqEnc} = \case
          -- received message does not have KEM in header,
          -- but the user enabled KEM when sending previous message
          Nothing -> case rcKEM of
-            Nothing | pqEnc && current rv >= pqRatchetE2EEncryptVersion -> do
+            Nothing | pqEnc -> do
              rcPQRs <- liftIO $ sntrup761Keypair g
              pure (Nothing, Nothing, Just RatchetKEM {rcPQRs, rcKEMs = Nothing})
            _ -> pure (Nothing, Nothing, Nothing)
          -- received message has KEM in header.
          Just (ARKP _ ps)
-            | pqEnc && current rv >= pqRatchetE2EEncryptVersion -> do
+            | pqEnc -> do
                -- state.PQRr = header.kem
                (ss, rcPQRr) <- sharedSecret
                -- state.PQRct = PQKEM-ENC(state.PQRr, state.PQRss) // encapsulated additional shared secret KEM #1
@@ -1148,9 +1114,9 @@ rcDecrypt g rc@Ratchet {rcRcv, rcAD = Str rcAD, rcVersion} rcMKSkipped msg' = do
        e -> throwE e
    -- header = HDECRYPT(state.NHKr, enc_header)
    decryptNextHeader hdr = (AdvanceRatchet,) <$> decryptHeader (rcNHKr rc) hdr
-    decryptHeader k EncMessageHeader {ehVersion, ehBody, ehAuthTag, ehIV} = do
+    decryptHeader k EncMessageHeader {ehBody, ehAuthTag, ehIV} = do
      header <- decryptAEAD k ehIV rcAD ehBody ehAuthTag `catchE` \_ -> throwE CERatchetHeader
-      parseE' CryptoHeaderError (msgHeaderP ehVersion) header
+      parseE' CryptoHeaderError smpP header
    decryptMessage :: MessageKey -> EncRatchetMessage -> ExceptT CryptoError IO (Either CryptoError ByteString)
    decryptMessage (MessageKey mk iv) EncRatchetMessage {emHeader, emBody, emAuthTag} =
      -- DECRYPT(mk, cipher-text, CONCAT(AD, enc_header))
@@ -1,11 +1,14 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE PatternSynonyms #-}

 module Simplex.Messaging.Crypto.SNTRUP761.Bindings
-  ( KEMPublicKey (..),
+  ( KEMPublicKey,
    KEMSecretKey,
-    KEMCiphertext (..),
-    KEMSharedKey (..),
+    KEMCiphertext,
+    KEMSharedKey,
+    pattern KEMPublicKey,
+    pattern KEMSharedKey,
    KEMKeyPair,
    sntrup761Keypair,
    sntrup761Enc,
@@ -25,8 +28,9 @@ import Simplex.Messaging.Crypto.SNTRUP761.Bindings.FFI
 import Simplex.Messaging.Crypto.SNTRUP761.Bindings.RNG (rngFuncPtr, withDRG)
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
+import Simplex.Messaging.Util ((<$?>))

-newtype KEMPublicKey = KEMPublicKey ByteString
+newtype KEMPublicKey = KEMPublicKey_ ByteString
  deriving (Eq, Show)

 newtype KEMSecretKey = KEMSecretKey ScrubbedBytes
@@ -35,18 +39,24 @@ newtype KEMSecretKey = KEMSecretKey ScrubbedBytes
 newtype KEMCiphertext = KEMCiphertext ByteString
  deriving (Eq, Show)

-newtype KEMSharedKey = KEMSharedKey ScrubbedBytes
+newtype KEMSharedKey = KEMSharedKey_ ScrubbedBytes
  deriving (Eq, Show)

-unsafeRevealKEMSharedKey :: KEMSharedKey -> String
-unsafeRevealKEMSharedKey (KEMSharedKey scrubbed) = show (BA.convert scrubbed :: ByteString)
-{-# DEPRECATED unsafeRevealKEMSharedKey "unsafeRevealKEMSharedKey left in code" #-}
+pattern KEMPublicKey :: ByteString -> KEMPublicKey
+pattern KEMPublicKey s <- KEMPublicKey_ s
+
+pattern KEMSharedKey :: ScrubbedBytes -> KEMSharedKey
+pattern KEMSharedKey s <- KEMSharedKey_ s
+
+{-# COMPLETE KEMPublicKey #-}
+
+{-# COMPLETE KEMSharedKey #-}

 type KEMKeyPair = (KEMPublicKey, KEMSecretKey)

 sntrup761Keypair :: TVar ChaChaDRG -> IO KEMKeyPair
 sntrup761Keypair drg =
-  bimap KEMPublicKey KEMSecretKey
+  bimap KEMPublicKey_ KEMSecretKey
    <$> BA.allocRet
      c_SNTRUP761_SECRETKEY_SIZE
      ( \skPtr ->
@@ -57,7 +67,7 @@ sntrup761Keypair drg =
 sntrup761Enc :: TVar ChaChaDRG -> KEMPublicKey -> IO (KEMCiphertext, KEMSharedKey)
 sntrup761Enc drg (KEMPublicKey pk) =
  BA.withByteArray pk $ \pkPtr ->
-    bimap KEMCiphertext KEMSharedKey
+    bimap KEMCiphertext KEMSharedKey_
      <$> BA.allocRet
        c_SNTRUP761_SIZE
        ( \kPtr ->
@@ -69,40 +79,47 @@ sntrup761Dec :: KEMCiphertext -> KEMSecretKey -> IO KEMSharedKey
 sntrup761Dec (KEMCiphertext c) (KEMSecretKey sk) =
  BA.withByteArray sk $ \skPtr ->
    BA.withByteArray c $ \cPtr ->
-      KEMSharedKey
+      KEMSharedKey_
        <$> BA.alloc c_SNTRUP761_SIZE (\kPtr -> c_sntrup761_dec kPtr cPtr skPtr)

+parseKey :: BA.ByteArrayAccess bs => (bs -> key) -> String -> Int -> bs -> Either String key
+parseKey kCon name expected s
+  | len == expected = Right $ kCon s
+  | otherwise = Left $ name <> " must be " <> show expected <> " bytes, got " <> show len
+  where
+    len = BA.length s    
+
 instance Encoding KEMSecretKey where
  smpEncode (KEMSecretKey c) = smpEncode . Large $ BA.convert c
-  smpP = KEMSecretKey . BA.convert . unLarge <$> smpP
+  smpP = parseKey KEMSecretKey "SNTRUP761 secret key" c_SNTRUP761_SECRETKEY_SIZE . BA.convert . unLarge <$?> smpP

 instance StrEncoding KEMSecretKey where
  strEncode (KEMSecretKey pk) = strEncode (BA.convert pk :: ByteString)
-  strP = KEMSecretKey . BA.convert <$> strP @ByteString
+  strP = parseKey KEMSecretKey "SNTRUP761 secret key" c_SNTRUP761_SECRETKEY_SIZE . BA.convert <$?> strP @ByteString

 instance Encoding KEMPublicKey where
  smpEncode (KEMPublicKey pk) = smpEncode . Large $ BA.convert pk
-  smpP = KEMPublicKey . BA.convert . unLarge <$> smpP
+  smpP = parseKey KEMPublicKey_ "SNTRUP761 public key" c_SNTRUP761_PUBLICKEY_SIZE . unLarge <$?> smpP

 instance StrEncoding KEMPublicKey where
  strEncode (KEMPublicKey pk) = strEncode (BA.convert pk :: ByteString)
-  strP = KEMPublicKey . BA.convert <$> strP @ByteString
+  strP = parseKey KEMPublicKey_ "SNTRUP761 public key" c_SNTRUP761_PUBLICKEY_SIZE <$?> strP @ByteString

 instance Encoding KEMCiphertext where
  smpEncode (KEMCiphertext c) = smpEncode . Large $ BA.convert c
-  smpP = KEMCiphertext . BA.convert . unLarge <$> smpP
+  smpP = parseKey KEMCiphertext "SNTRUP761 ciphertext" c_SNTRUP761_CIPHERTEXT_SIZE . unLarge <$?> smpP

 instance Encoding KEMSharedKey where
  smpEncode (KEMSharedKey c) = smpEncode (BA.convert c :: ByteString)
-  smpP = KEMSharedKey . BA.convert <$> smpP @ByteString
+  smpP = KEMSharedKey_ . BA.convert <$> smpP @ByteString

 instance StrEncoding KEMCiphertext where
  strEncode (KEMCiphertext pk) = strEncode (BA.convert pk :: ByteString)
-  strP = KEMCiphertext . BA.convert <$> strP @ByteString
+  strP = parseKey KEMCiphertext "SNTRUP761 ciphertext" c_SNTRUP761_CIPHERTEXT_SIZE <$?> strP @ByteString

 instance StrEncoding KEMSharedKey where
  strEncode (KEMSharedKey pk) = strEncode (BA.convert pk :: ByteString)
-  strP = KEMSharedKey . BA.convert <$> strP @ByteString
+  strP = KEMSharedKey_ . BA.convert <$> strP @ByteString

 instance ToJSON KEMSecretKey where
  toJSON = strToJSON
@@ -130,9 +147,9 @@ instance ToField KEMSharedKey where

 instance FromField KEMSharedKey where
 #if defined(dbPostgres)
-  fromField f dat = KEMSharedKey . BA.convert @ByteString <$> fromField f dat
+  fromField f dat = KEMSharedKey_ . BA.convert @ByteString <$> fromField f dat
 #else
-  fromField f = KEMSharedKey . BA.convert @ByteString <$> fromField f
+  fromField f = KEMSharedKey_ . BA.convert @ByteString <$> fromField f
 #endif

 instance ToJSON KEMSharedKey where
@@ -53,14 +53,14 @@ invShortLinkKdf :: LinkKey -> C.SbKey
 invShortLinkKdf (LinkKey k) = C.unsafeSbKey $ C.hkdf "" k "SimpleXInvLink" 32

 encodeSignLinkData :: forall c. ConnectionModeI c => C.KeyPairEd25519 -> VersionRangeSMPA -> ConnectionRequestUri c -> Maybe ByteString -> UserConnLinkData c -> (LinkKey, (ByteString, ByteString))
-encodeSignLinkData keys@(_, pk) agentVRange linkConnReq linkEntityId userData =
-  let (linkKey, fd) = encodeSignFixedData keys agentVRange linkConnReq linkEntityId
+encodeSignLinkData keys@(_, pk) agentVRange connReq linkEntityId userData =
+  let (linkKey, fd) = encodeSignFixedData keys agentVRange connReq linkEntityId
      md = encodeSignUserData (sConnectionMode @c) pk agentVRange userData
   in (linkKey, (fd, md))

 encodeSignFixedData :: ConnectionModeI c => C.KeyPairEd25519 -> VersionRangeSMPA -> ConnectionRequestUri c -> Maybe ByteString -> (LinkKey, ByteString)
-encodeSignFixedData (rootKey, pk) agentVRange linkConnReq linkEntityId =
-  let fd = smpEncode FixedLinkData {agentVRange, rootKey, linkConnReq, linkEntityId}
+encodeSignFixedData (rootKey, pk) agentVRange connReq linkEntityId =
+  let fd = smpEncode FixedLinkData {agentVRange, rootKey, linkConnReq = binaryConnReq connReq, linkEntityId}
   in (LinkKey (C.sha3_256 fd), encodeSign pk fd)

 encodeSignUserData :: ConnectionModeI c => SConnectionMode c -> C.PrivateKeyEd25519 -> VersionRangeSMPA -> UserConnLinkData c -> ByteString
@@ -120,6 +120,6 @@ decryptLinkData linkKey k (encFD, encMD) = do
      pure (sig, s)
    decode :: Encoding a => ByteString -> Either AgentErrorType a
    decode = msgErr . smpDecode
-    msgErr = first (const $ AGENT A_MESSAGE)
+    msgErr = first (const $ AGENT $ A_MESSAGE "parse link data")
    linkErr :: String -> Either AgentErrorType ()
    linkErr = Left . AGENT . A_LINK
@@ -11,6 +11,7 @@ module Simplex.Messaging.Encoding
  ( Encoding (..),
    Tail (..),
    Large (..),
+    EncList (..),
    _smpP,
    smpEncodeList,
    smpListP,
@@ -177,6 +178,12 @@ instance Encoding a => Encoding (L.NonEmpty a) where
      0 -> fail "empty list"
      n -> L.fromList <$> A.count n smpP

+newtype EncList a = EncList [a]
+
+instance Encoding a => Encoding (EncList a) where
+  smpEncode (EncList xs) = smpEncodeList xs
+  smpP = EncList <$> smpListP
+
 instance (Encoding a, Encoding b) => Encoding (a, b) where
  smpEncode (a, b) = smpEncode a <> smpEncode b
  {-# INLINE smpEncode #-}
@@ -1,10 +1,14 @@
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE KindSignatures #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}

 module Simplex.Messaging.Encoding.String
  ( TextEncoding (..),
    StrEncoding (..),
    Str (..),
+    StrJSON (..),
    strP_,
    _strP,
    strToJSON,
@@ -34,6 +38,7 @@ import Data.Int (Int64)
 import Data.IntSet (IntSet)
 import qualified Data.IntSet as IS
 import qualified Data.List.NonEmpty as L
+import Data.Proxy (Proxy (..))
 import Data.Set (Set)
 import qualified Data.Set as S
 import Data.Text (Text)
@@ -44,6 +49,7 @@ import Data.Time.Format.ISO8601
 import Data.Word (Word16, Word32)
 import qualified Data.X509 as X
 import qualified Data.X509.Validation as XV
+import GHC.TypeLits (KnownSymbol, Symbol, symbolVal)
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Parsers (parseAll)
 import Simplex.Messaging.Util (bshow, safeDecodeUtf8, (<$?>))
@@ -247,3 +253,21 @@ textToEncoding = JE.text . textEncode

 textParseJSON :: TextEncoding a => String -> J.Value -> JT.Parser a
 textParseJSON name = J.withText name $ maybe (fail name) pure . textDecode
+
+-- | Derives ToJSON/FromJSON from the wrapped type's own StrEncoding (a base64url
+-- string), so any validation that StrEncoding performs (e.g. length) also applies
+-- to JSON parsing. The @name@ symbol is the parse error label. The type parameter
+-- @a@ is essential: it makes parseJSON resolve at the wrapped type rather than at
+-- ByteString. Use via DerivingVia, e.g.:
+--
+-- > newtype Key = Key ByteString
+-- >   deriving (ToJSON, FromJSON) via (StrJSON "Key" Key)
+newtype StrJSON (name :: Symbol) a = StrJSON {unStrJSON :: a}
+  deriving (Eq, Show)
+
+instance StrEncoding a => ToJSON (StrJSON name a) where
+  toJSON (StrJSON a) = strToJSON a
+  toEncoding (StrJSON a) = strToJEncoding a
+
+instance forall name a. (KnownSymbol name, StrEncoding a) => FromJSON (StrJSON name a) where
+  parseJSON = fmap StrJSON . strParseJSON (symbolVal (Proxy :: Proxy name))
@@ -0,0 +1,46 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE StrictData #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+module Simplex.Messaging.Names.Record
+  ( NameRecord (..),
+  )
+where
+
+import qualified Data.Aeson as J
+import qualified Data.Aeson.TH as JQ
+import Data.Text (Text)
+import Simplex.Messaging.Parsers (defaultJSON, dropPrefix)
+
+-- | Resolved name record returned by the names role. JSON keys match the
+--   resolver REST output; both FromJSON (resolver -> server) and ToJSON
+--   (server diagnostics) are TH-derived from one Options value, so the Haskell
+--   type IS the schema. Text fields use the empty string as the "unset"
+--   sentinel; coin fields use JSON null. simplexContact / simplexChannel are
+--   arrays of links (primary first, empty when unset) so a name can advertise
+--   fallback SMP servers. owner / resolver are 0x-hex Ethereum addresses, kept
+--   verbatim as text (the resolver is the source of truth for their validity).
+--   The only size bound is the SMP transport block (enforced by the framing).
+data NameRecord = NameRecord
+  { nrName :: Text,
+    nrNickname :: Text,
+    nrWebsite :: Text,
+    nrLocation :: Text,
+    nrSimplexContact :: [Text],
+    nrSimplexChannel :: [Text],
+    nrEth :: Maybe Text,
+    nrBtc :: Maybe Text,
+    nrXmr :: Maybe Text,
+    nrDot :: Maybe Text,
+    nrOwner :: Text,
+    nrResolver :: Text -- resolver address (0x hex) that produced the record
+  }
+  deriving (Eq, Show)
+
+-- omitNothingFields False so absent coin fields surface as JSON null (matches
+-- the resolver output for unset coins).
+$( JQ.deriveJSON
+    defaultJSON {J.omitNothingFields = False, J.fieldLabelModifier = dropPrefix "nr"}
+    ''NameRecord
+ )
--- a/Show More
+++ b/Show More