6.5.0.9

* explicit exports

* more empty exports

* add exports

* reorder

* use correct ControlProtocol type for xftp router

---------

Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>

.github/workflows/build.yml

@@ -58,11 +58,11 @@ jobs:
 # =============================
 
   build:
-    name: "ubuntu-${{ matrix.os }}, GHC: ${{ matrix.ghc }}"
+    name: "ubuntu-${{ matrix.os }}-${{ matrix.arch }}, GHC: ${{ matrix.ghc }}"
     needs: maybe-release
     env:
       apps: "smp-server xftp-server ntf-server xftp"
-    runs-on: ubuntu-${{ matrix.os }}
+    runs-on: ${{ matrix.runner }}
     services:
       postgres:
         image: postgres:15
@@ -81,16 +81,34 @@ jobs:
       matrix:
         include:
           - os: 22.04
+            os_underscore: 22_04
+            arch: x86-64
+            runner: "ubuntu-22.04"
             ghc: "8.10.7"
-            platform_name: 22_04-8.10.7
             should_run: ${{ !(github.ref == 'refs/heads/stable' || startsWith(github.ref, 'refs/tags/v')) }}
           - os: 22.04
+            os_underscore: 22_04
+            arch: x86-64
+            runner: "ubuntu-22.04"
             ghc: "9.6.3"
-            platform_name: 22_04-x86-64
             should_run: true
           - os: 24.04
+            os_underscore: 24_04
+            arch: x86-64
+            runner: "ubuntu-24.04"
+            ghc: "9.6.3"
+            should_run: true
+          - os: 22.04
+            os_underscore: 22_04
+            arch: aarch64
+            runner: "ubuntu-22.04-arm"
+            ghc: "9.6.3"
+            should_run: true
+          - os: 24.04
+            os_underscore: 24_04
+            arch: aarch64
+            runner: "ubuntu-24.04-arm"
             ghc: "9.6.3"
-            platform_name: 24_04-x86-64
             should_run: true
     steps:
       - name: Clone project
@@ -127,11 +145,7 @@ jobs:
           context: .
           load: true
           file: Dockerfile.build
-          tags: build/${{ matrix.platform_name }}:latest
-          cache-from: |
-            type=gha
-            type=gha,scope=master
-          cache-to: type=gha,mode=max
+          tags: build/${{ matrix.os }}:latest
           build-args: |
             TAG=${{ matrix.os }}
             GHC=${{ matrix.ghc }}
@@ -143,23 +157,28 @@ jobs:
           path: |
             ~/.cabal/store
             dist-newstyle
-          key: ${{ matrix.os }}-${{ hashFiles('cabal.project', 'simplexmq.cabal') }}
+          key: ubuntu-${{ matrix.os }}-${{ matrix.arch }}-ghc${{ matrix.ghc }}-${{ hashFiles('cabal.project', 'simplexmq.cabal') }}
 
       - name: Start container
         if: matrix.should_run == true
         shell: bash
         run: |
           docker run -t -d \
+            --device /dev/fuse \
+            --cap-add SYS_ADMIN \
+            --security-opt apparmor:unconfined \
             --name builder \
             -v ~/.cabal:/root/.cabal \
             -v /home/runner/work/_temp:/home/runner/work/_temp \
             -v ${{ github.workspace }}:/project \
-            build/${{ matrix.platform_name }}:latest
+            build/${{ matrix.os }}:latest
 
       - name: Build smp-server (postgresql) and tests
         if: matrix.should_run == true
         shell: docker exec -t builder sh -eu {0}
         run: |
+          chmod -fR 777 ~/.cabal ./dist-newstyle || :; git config --global --add safe.directory '*'
+          cabal clean
           cabal update
           cabal build --jobs=$(nproc) --enable-tests -fserver_postgres
           mkdir -p /out
@@ -181,7 +200,7 @@ jobs:
         id: prepare-postgres
         shell: bash
         run: |
-          name="smp-server-postgres-ubuntu-${{ matrix.platform_name }}"
+          name="smp-server-postgres-ubuntu-${{ matrix.os_underscore }}-${{ matrix.arch }}"
           docker cp builder:/out/smp-server $name
 
           path="${{ github.workspace }}/$name"
@@ -213,9 +232,9 @@ jobs:
           printf 'bins<<EOF\n' > bins.output
           printf 'hashes<<EOF\n' > hashes.output
           for i in ${{ env.apps }}; do
-            mv ./out/$i ./$i-ubuntu-${{ matrix.platform_name }}
+            name="$i-ubuntu-${{ matrix.os_underscore }}-${{ matrix.arch }}"
 
-            name="$i-ubuntu-${{ matrix.platform_name }}"
+            mv ./out/$i ./$name
 
             path="${{ github.workspace }}/$name"
             hash="SHA2-256($name)= $(openssl sha256 $path | cut -d' ' -f 2)"
@@ -246,7 +265,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Test
-        if: matrix.should_run == true
+        if: matrix.should_run == true && matrix.arch == 'x86-64'
         timeout-minutes: 120
         shell: bash
         env:

.github/workflows/docker-image.yml

@@ -39,9 +39,17 @@ jobs:
             type=semver,pattern=v{{major}}.{{minor}}
             type=semver,pattern=v{{major}}
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Build and push Docker image
         uses: simplex-chat/docker-build-push-action@v6
         with:
+          context: .
+          platforms: linux/amd64,linux/arm64
           push: true
           build-args: |
             APP=${{ matrix.app }}

.github/workflows/reproduce-schedule.yml

@@ -25,7 +25,7 @@ jobs:
 
       - name: Execute reproduce script
         run: |
-          ${GITHUB_WORKSPACE}/scripts/reproduce-builds.sh "$TAG"
+          ${GITHUB_WORKSPACE}/scripts/simplexmq-reproduce-builds.sh "$TAG" || :
 
       - name: Check if build has been reproduced
         env:
@@ -33,7 +33,7 @@ jobs:
           user: ${{ secrets.STATUS_SIMPLEX_WEBHOOK_USER }}
           pass: ${{ secrets.STATUS_SIMPLEX_WEBHOOK_PASS }}
         run: |
-          if [ -f "${GITHUB_WORKSPACE}/$TAG/_sha256sums" ]; then
+          if [ -f "${GITHUB_WORKSPACE}/${TAG}-simplexmq/_sha256sums" ]; then
             exit 0
           else
             curl --proto '=https' --tlsv1.2 -sSf \

.gitignore

@@ -11,3 +11,4 @@ cabal.project.local~
 .hpc/
 *.tix
 .coverage
+

2026-02-04-xftp-web-persistent-connections.md

@@ -0,0 +1,53 @@
+# XFTPClientAgent Pattern
+
+## TOC
+1. Executive Summary
+2. Changes: client.ts
+3. Changes: agent.ts
+4. Changes: test/browser.test.ts
+5. Verification
+
+## Executive Summary
+
+Add `XFTPClientAgent` — a per-server connection pool matching the Haskell pattern. The agent caches `XFTPClient` instances by server URL. All orchestration functions (`uploadFile`, `downloadFile`, `deleteFile`) take `agent` as first parameter and use `getXFTPServerClient(agent, server)` instead of calling `connectXFTP` directly. Connections stay open on success; the caller creates and closes the agent.
+
+`connectXFTP` and `closeXFTP` stay exported (used by `XFTPWebTests.hs` Haskell tests). The `browserClients` hack, per-function `connections: Map`, and `getOrConnect` are deleted.
+
+## Changes: client.ts
+
+**Add** after types section: `XFTPClientAgent` interface, `newXFTPAgent`, `getXFTPServerClient`, `closeXFTPServerClient`, `closeXFTPAgent`.
+
+**Delete**: `browserClients` Map and all `isNode` browser-cache checks in `connectXFTP` and `closeXFTP`.
+
+**Revert `closeXFTP`** to unconditional `c.transport.close()` (browser transport.close() is already a no-op).
+
+`connectXFTP` stays exported (backward compat) but becomes a raw low-level function — no caching.
+
+## Changes: agent.ts
+
+**Imports**: replace `connectXFTP`/`closeXFTP` with `getXFTPServerClient`/`closeXFTPAgent` etc.
+
+**Re-export** from agent.ts: `newXFTPAgent`, `closeXFTPAgent`, `XFTPClientAgent`.
+
+**`uploadFile`**: add `agent: XFTPClientAgent` as first param. Replace `connectXFTP` → `getXFTPServerClient`. Remove `finally { closeXFTP }`. Pass `agent` to `uploadRedirectDescription`.
+
+**`uploadRedirectDescription`**: change from `(client, server, innerFd)` to `(agent, server, innerFd)`. Get client via `getXFTPServerClient`.
+
+**`downloadFile`**: add `agent` param. Delete local `connections: Map`. Replace `getOrConnect` → `getXFTPServerClient`. Remove finally cleanup. Pass `agent` to `downloadWithRedirect`.
+
+**`downloadWithRedirect`**: add `agent` param. Same replacements. Remove try/catch cleanup. Recursive call passes `agent`.
+
+**`deleteFile`**: add `agent` param. Same pattern.
+
+**Delete**: `getOrConnect` function entirely.
+
+## Changes: test/browser.test.ts
+
+Create agent before operations, pass to upload/download, close in finally.
+
+## Verification
+
+1. `npx vitest --run` — browser round-trip test passes
+2. No remaining `browserClients`, `getOrConnect`, or per-function `connections: Map` locals
+3. `connectXFTP` and `closeXFTP` still exported (XFTPWebTests.hs compat)
+4. All orchestration functions take `agent` as first param

CHANGELOG.md

@@ -1,3 +1,34 @@
+# 6.4.4
+
+Servers:
+- fix server pages when source code is not specified.
+- include commit SHA in printed version and in web page (#1608).
+
+SMP server:
+- support short SimpleX addresses in server information page (#1600).
+- wrap all queries in transactions (#1603).
+
+SMP agent:
+- chat relay address type for short links (#1602).
+- extend xrcp certificate validity 1 hour in the past, to allow out of sync clocks (#1601).
+
+# 6.4.3
+
+SMP agent:
+- fix some connection errors by updating contact request server hosts to match server in short link (#1597).
+
+SMP server:
+- support short link URI as queue identifier in control port commands (#1596).
+
+# 6.4.2
+
+SMP server:
+- fix memory leak when connection interrupts straight after client connects.
+- do not include repeated queue blocking into stats/quota.
+
+XFTP server:
+- prometheus metrics
+
 # 6.4.1
 
 SMP protocol:

apps/smp-server/static/index.html

@@ -223,11 +223,14 @@
             <table id="public-info">
               <tr class="text-grey-black dark:text-white text-base">
                 <td>Server version:</td>
-                <td>${version}</td>
+                <td>${version}<x-commit> / <a href="${commitSourceCode}/commit/${commit}" target="_blank">${shortCommit}</a></x-commit></td>
               </tr>
               <tr class="text-grey-black dark:text-white text-base">
                 <td>Source code:</td>
-                <td><a href="${sourceCode}" target="_blank">${sourceCode}</a></td>
+                <td>
+                  <x-sourceCode><a href="${sourceCode}" target="_blank">${sourceCode}</a></x-sourceCode>
+                  <x-noSourceCode>add to smp-server.ini (required by <a href="https://github.com/simplex-chat/simplexmq/blob/stable/LICENSE" target="_blank">AGPLv3</a>)</x-noSourceCode>
+                </td>
               </tr>
               <x-website>
                 <tr class="text-grey-black dark:text-white text-base">

apps/smp-server/static/link.html

@@ -512,6 +512,8 @@
         element.innerHTML = 'This is a one-time link of the SimpleX network user'
       } else if (url.includes('/c')) {
         element.innerHTML = 'This is a public channel address on SimpleX network'
+      } else if (url.includes('/r')) {
+        element.innerHTML = 'This is a chat relay address on SimpleX network'
       }
     }
   </script>

apps/smp-server/web/Static.hs

@@ -12,6 +12,7 @@ import Data.Char (toUpper)
 import Data.IORef (readIORef)
 import Data.Maybe (fromMaybe)
 import Data.String (fromString)
+import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
 import Network.Socket (getPeerName)
 import Network.Wai (Application, Request (..))
@@ -22,8 +23,9 @@ import qualified Network.Wai.Handler.Warp.Internal as WI
 import qualified Network.Wai.Handler.WarpTLS as WT
 import Simplex.Messaging.Encoding.String (strEncode)
 import Simplex.Messaging.Server (AttachHTTP)
+import Simplex.Messaging.Server.CLI (simplexmqCommit)
 import Simplex.Messaging.Server.Information
-import Simplex.Messaging.Server.Main (EmbeddedWebParams (..), WebHttpsParams (..))
+import Simplex.Messaging.Server.Main (EmbeddedWebParams (..), WebHttpsParams (..), simplexmqSource)
 import Simplex.Messaging.Transport (simplexMQVersion)
 import Simplex.Messaging.Transport.Client (TransportHost (..))
 import Simplex.Messaging.Util (tshow)
@@ -103,6 +105,7 @@ generateSite si onionHost sitePath = do
   createLinkPage "a"
   createLinkPage "c"
   createLinkPage "g"
+  createLinkPage "r"
   createLinkPage "i"
   logInfo $ "Generated static site contents at " <> tshow sitePath
   where
@@ -116,7 +119,7 @@ generateSite si onionHost sitePath = do
 serverInformation :: ServerInformation -> Maybe TransportHost -> ByteString
 serverInformation ServerInformation {config, information} onionHost = render E.indexHtml substs
   where
-    substs = substConfig <> maybe [] substInfo information <> [("onionHost", strEncode <$> onionHost)]
+    substs = substConfig <> substInfo <> [("onionHost", strEncode <$> onionHost)]
     substConfig =
       [ ( "persistence",
           Just $ case persistence config of
@@ -131,7 +134,7 @@ serverInformation ServerInformation {config, information} onionHost = render E.i
       ]
     yesNo True = "Yes"
     yesNo False = "No"
-    substInfo spi =
+    substInfo =
       concat
         [ basic,
           maybe [("usageConditions", Nothing), ("usageAmendments", Nothing)] conds (usageConditions spi),
@@ -143,10 +146,16 @@ serverInformation ServerInformation {config, information} onionHost = render E.i
         ]
       where
         basic =
-          [ ("sourceCode", Just . encodeUtf8 $ sourceCode spi),
+          [ ("sourceCode", if T.null sc then Nothing else Just (encodeUtf8 sc)),
+            ("noSourceCode", if T.null sc then Just "none" else Nothing),
             ("version", Just $ B.pack simplexMQVersion),
+            ("commitSourceCode", Just $ encodeUtf8 $ maybe (T.pack simplexmqSource) sourceCode information),
+            ("shortCommit", Just $ B.pack $ take 7 simplexmqCommit),
+            ("commit", Just $ B.pack simplexmqCommit),
             ("website", encodeUtf8 <$> website spi)
           ]
+        spi = fromMaybe (emptyServerInfo "") information
+        sc = sourceCode spi
         conds ServerConditions {conditions, amendments} =
           [ ("usageConditions", Just $ encodeUtf8 conditions),
             ("usageAmendments", encodeUtf8 <$> amendments)
@@ -228,8 +237,8 @@ section_ label content' src =
         (inside, next') ->
           let next = B.drop (B.length endMarker) next'
            in case content' of
-                Nothing -> before <> next -- collapse section
-                Just content -> before <> item_ label content inside <> section_ label content' next
+                Just content | not (B.null content) -> before <> item_ label content inside <> section_ label content' next
+                _ -> before <> next -- collapse section
   where
     startMarker = "<x-" <> label <> ">"
     endMarker = "</x-" <> label <> ">"

contributing/CODE.md

@@ -0,0 +1,104 @@
+# Coding and building
+
+This file provides guidance on coding style and approaches and on building the code.
+
+## Code Security
+
+When designing code and planning implementations:
+- Apply adversarial thinking, and consider what may happen if one of the communicating parties is malicious.
+- Formulate an explicit threat model for each change - who can do which undesirable things and under which circumstances.
+
+## Code Quality Standards
+
+Haskell client and server code serves as system specification, not just implementation — we use type-driven design to reflect the business domain in types. Quality, conciseness, and clarity of Haskell code are critical.
+
+## Code Style, Formatting and Approaches
+
+The project uses **fourmolu** for Haskell code formatting. Configuration is in `fourmolu.yaml`.
+
+**Key formatting rules:**
+- 2-space indentation
+- Trailing function arrows, commas, and import/export style
+- Record brace without space: `{field = value}`
+- Single newline between declarations
+- Never use unicode symbols
+- Inline `let` style with right-aligned `in`
+
+**Format code before committing:**
+
+```bash
+# Format a single file
+fourmolu -i src/Simplex/Messaging/Protocol.hs
+```
+
+Some files that use CPP language extension cannot be formatted as a whole, so individual code fragments need to be formatted.
+
+**Follow existing code patterns:**
+- Match the style of surrounding code
+- Use qualified imports with short aliases (e.g., `import qualified Data.ByteString.Char8 as B`)
+- Use record syntax for types with multiple fields
+- Prefer explicit pattern matching over partial functions
+
+**Comments policy:**
+- Avoid redundant comments that restate what the code already says
+- Only comment on non-obvious design decisions or tricky implementation details
+- Function names and type signatures should be self-documenting
+- Do not add comments like "wire format encoding" (Encoding class is always wire format) or "check if X" when the function name already says that
+- Assume a competent Haskell reader
+
+**Diff and refactoring:**
+- Avoid unnecessary changes and code movements
+- Never do refactoring unless it substantially reduces cost of solving the current problem, including the cost of refactoring
+- Aim to minimize the code changes - do what is minimally required to solve users' problems
+
+**Document and code structure:**
+- **Never move existing code or sections around** - add new content at appropriate locations without reorganizing existing structure.
+- When adding new sections to documents, continue the existing numbering scheme.
+- Minimize diff size - prefer small, targeted changes over reorganization.
+
+**Code analysis and review:**
+- Trace data flows end-to-end: from origin, through storage/parameters, to consumption. Flag values that are discarded and reconstructed from partial data (e.g. extracted from a URI missing original fields) — this is usually a bug.
+- Read implementations of called functions, not just signatures — if duplication involves a called function, check whether decomposing it resolves the duplication.
+- Do not save time on analysis. Read every function in the data flow even when the interface seems clear — wrong assumptions about internals are the main source of missed bugs.
+
+### Haskell Extensions
+- `StrictData` enabled by default
+- Use STM for safe concurrency
+- Assume concurrency in PostgreSQL queries
+- Comprehensive warning flags with strict pattern matching
+
+## Build Commands
+
+```bash
+# Standard build
+cabal build
+
+# Fast build
+cabal build --ghc-options -O0
+
+# Build specific executables
+cabal build exe:smp-server exe:xftp-server exe:ntf-server exe:xftp
+
+# Build with PostgreSQL server support
+cabal build -fserver_postgres
+
+# Client-only library build (no server code)
+cabal build -fclient_library
+
+# Find binary location
+cabal list-bin exe:smp-server
+```
+
+### Cabal Flags
+
+- `swift`: Enable Swift JSON format
+- `client_library`: Build without server code
+- `client_postgres`: Use PostgreSQL instead of SQLite for agent persistence
+- `server_postgres`: PostgreSQL support for server queue/notification store
+
+## External Dependencies
+
+Custom forks specified in `cabal.project`:
+- `aeson`, `hs-socks` (SimpleX forks)
+- `direct-sqlcipher`, `sqlcipher-simple` (encrypted SQLite)
+- `warp`, `warp-tls` (HTTP server)

contributing/PROJECT.md

@@ -0,0 +1,105 @@
+# SimpleXMQ repository
+
+This file provides guidance on the project structure to help working with code in this repository.
+
+## Project Overview
+
+SimpleXMQ is a Haskell message broker implementing unidirectional (simplex) queues for privacy-preserving messaging. 
+
+Key components:
+
+- **SimpleX Messaging Protocol**: SMP protocol definition and encodings ([code](../src/Simplex/Messaging/Protocol.hs), [transport code](../src/Simplex/Messaging/Transport.hs), [spec](../protocol/simplex-messaging.md)).
+- **SMP Server**: Message broker with TLS, in-memory queues, optional persistence ([main code](../src/Simplex/Messaging/Server.hs), [all code files](../src/Simplex/Messaging/Server/), [executable](../apps/smp-server/)). For proxying SMP commands the server uses [lightweight SMP client](../src/Simplex/Messaging/Client/Agent.hs).
+- **SMP Client**: Functional API with STM-based message delivery ([code](../src/Simplex/Messaging/Client.hs)).
+- **SMP Agent**: High-level duplex connections via multiple simplex queues with E2E encryption ([code](../src/Simplex/Messaging/Agent.hs)). Implements Agent-to-agent protocol ([code](../src/Simplex/Messaging/Agent/Protocol.hs), [spec](../protocol/agent-protocol.md)) via intermediary agent client ([code](../src/Simplex/Messaging/Agent/Client.hs)).
+- **XFTP**: SimpleX File Transfer Protocol, server and CLI client ([code](../src/Simplex/FileTransfer/), [spec](../protocol/xftp.md)).
+- **XRCP**: SimpleX Remote Control Protocol ([code](`../src/Simplex/RemoteControl/`), [spec](../protocol/xrcp.md)).
+- **Notifications**: Push notifications server requires PostgreSQL ([code](../src/Simplex/Messaging/Notifications), [executable](../apps/ntf-server/)). Client protocol is used for clients to communicate with the server ([code](../src/Simplex/Messaging/Notifications/Protocol.hs), [spec](../protocol/push-notifications.md)). For subscribing to SMP notifications the server uses [lightweight SMP client](../src/Simplex/Messaging/Client/Agent.hs).
+
+## Architecture
+
+For general overview see `../protocol/overview-tjr.md`.
+
+SMP Protocol Layers:
+
+```
+TLS Transport → SMP Protocol → Agent Protocol → Application protocol
+```
+
+XFTP Protocol Layers:
+
+```
+TLS Transport (HTTP2 encoding) → XFTP Protocol → Out-of-band file descriptions
+```
+
+## Key Patterns
+
+1. **Persistence**: All queue state managed via Software Transactional Memory or via PostgreSQL
+   - `Simplex.Messaging.Server.MsgStore.STM` - in-memory messages
+   - `Simplex.Messaging.Server.QueueStore.STM` - in-memory queue state
+   - `Simplex.Messaging.Server.MsgStore.Postgres` - message storage
+   - `Simplex.Messaging.Server.QueueStore.Postgres` - queue storage
+
+2. **Append-Only Store Log**: Optional persistence via journal for in-memory storage
+   - `Simplex.Messaging.Server.StoreLog` - queue creation log
+   - Compacted on restart
+
+3. **Agent Storage**:
+   - SQLite (default) or PostgreSQL
+   - Migrations in `src/Simplex/Messaging/Agent/Store/{SQLite,Postgres}/Migrations/`
+
+4. **Protocol Versioning**: All layers support version negotiation
+   - `Simplex.Messaging.Version` - version range utilities
+
+5. **Double Ratchet E2E**: Per-connection encryption
+   - `Simplex.Messaging.Crypto.Ratchet`
+   - SNTRUP761 post-quantum KEM (`src/Simplex/Messaging/Crypto/SNTRUP761/`)
+
+## Source Layout
+
+```
+src/Simplex/
+├── Messaging/
+│   ├── Agent.hs          # Main agent (~210KB)
+│   ├── Server.hs         # SMP server (~130KB)
+│   ├── Client.hs         # Client API (~65KB)
+│   ├── Protocol.hs       # Protocol types (~77KB)
+│   ├── Crypto.hs         # E2E encryption (~52KB)
+│   ├── Transport.hs      # Transport encoding over TLS
+│   ├── Agent/Store/      # SQLite/Postgres persistence
+│   ├── Server/           # Server internals (QueueStore, MsgStore, Control)
+│   └── Notifications/    # Push notification system
+├── FileTransfer/         # XFTP implementation for file transfers
+└── RemoteControl/        # XRCP implementation for device discovery & control
+```
+
+## Protocol Documentation
+
+- `protocol/overview-tjr.md`: SMP protocols stack overview
+- `protocol/simplex-messaging.md`: SMP protocol spec (v19)
+- `protocol/agent-protocol.md`: Agent protocol spec (v7)
+- `protocol/xftp.md`: File transfer protocol
+- `protocol/xrcp.md`: Remote control protocol
+- `rfcs/`: Design RFCs for features
+
+## Testing
+
+```bash
+# Run all tests
+cabal test --test-show-details=streaming
+
+# Run specific test group (uses HSpec)
+cabal test --test-option=--match="/Core tests/Encryption tests/"
+
+# Run single test
+cabal test --test-option=--match="/SMP client agent/functional API/"
+```
+
+Tests require PostgreSQL running on `localhost:5432` when using `-fserver_postgres` or `-fclient_postgres`.
+
+Test files are in `tests/` with structure:
+- `Test.hs`: Main runner
+- `AgentTests/`: Agent protocol and connection tests
+- `CoreTests/`: Crypto, encoding, storage tests
+- `ServerTests.hs`: SMP server tests
+- `XFTPServerTests.hs`: File transfer tests

contributing/README.md

@@ -0,0 +1,23 @@
+# Contributing to SimpleX repositories
+
+## Focus on user problems
+
+We do not make code changes to improve code - any change must address a specific user problem or request.
+
+## Discuss the plans as early as possible
+
+Please discuss the problem you want to solve and your detailed implementation plan with the project team prior to contributing, to avoid wasted time and additional changes. Acceptance of your contribution depends on your willingness and ability to iterate the proposed contribution to achieve the required quality level, coding style, test coverage, and alignment with user requirements as they are understood by the project team.
+
+## Follow project structure, coding style and approaches
+
+./PROJECT.md has information about the structure of this `simplexmq` repository.
+
+./CODE.md has details about general requirements common for `simplexmq` and `simplex-chat` repositories.
+
+This files can be used with LLM prompts, e.g. if you use Claude Code you can create CLAUDE.md file in project root importing content from these files:
+
+```markdown
+@README.md
+@contributing/PROJECT.md
+@contributing/CODE.md
+```

notes-flow.txt

@@ -1,23 +0,0 @@
-common:
-  corrId - random BS, used as CbNonce
-  entityId - p2r tlsUniq
-
-# setup
-s->p: "proxy", uri, auth?
-  # unless connected
-  p->r: "p_handshake"
-  p<-r: "r_key", tls-signed dh pub
-s<-r: "r_key", tls-signed dh pub # reply entityId contains tlsUniq
-
-# working
-s ; generate random dh priv, make shared secret
-s->p: s2r("forward", random dh pub, SEND command blob)
-  p->r: p2r("forward", random dh pub, s2r("forward", ...)))
-    r->c@ "msg", ...
-  p<-r: p2r("r_res", s2r("ok" / "error", error))
-s<-p@ s2r("ok" / "error", error)
-
-# expired
-  p<-r@ p2r("error", "key expired")
-s<-p@ "error", "key expired"
-s ; reconnect

rfcs/2025-07-15-multi-device.md

@@ -0,0 +1,104 @@
+# Using the same profile from multiple devices
+
+## Problem
+
+Double Ratchet algorithm makes it hard to send/receive messages sent to the user from different devices, as each message changes the state of Double Ratchet keys, and these state changes must be strictly sequential and they cannot be reversed (although skipping is possible).
+
+Traditional approach for multi-device converts each direct conversation into a group, where each device participates as a member. Likewise, for group conversations each device also participates as a member. While these members *look* as if they are the same user to others, a very simple client app modification may show device ID for each message, and the communication peers, both in direct chats and in groups would know how many devices a user has and which device the user sent the message from. In addition to that, with this approach communication peers can send different messages to different devices (it can be prevented by provider who would request that only message key is encrypted with DR, while the encrypted message is the same) or withheld from some devices (it cannot be prevented by provider, as it cannot add key to the communication in case it is missing, and cannot withhold the message completely too). These opens various vectors for targeted attacks, e.g.:
+- tracking movements of the user: once each devices is identified as "desk" and "phone" it would allow to know where the user is at a given time.
+- manipulating information by sending messages to one device (to have proof it was sent) and withholding from others, or sending different messages if the protocol allows it.
+
+In addition to that, the specific implementation of this approach in Signal compromises break-in recovery property (aka post-compromise security) of Double-Ratchet algorithm, making its design ineffective - the only reason to have the second ratchet in DR algorithm is to provide break-in recovery, without it a much simpler design with a single ratchet is sufficient. See [this paper](https://eprint.iacr.org/2021/626.pdf) for details.
+
+While this limitation can be addressed with notifications when a new device is added and per-device keys, we still find the remaining attack vectors on user security and privacy to be unacceptable, and opening unsuspecting users to various criminal actions - and it is wrong to say that would only affect security conscious users, and most people would not be affected by these risks. Allowing potential criminals in groups to know which device you are currently using is a real risk for all users.
+
+Another approach was offered by Threema that is ["mediator" server](https://threema.com/en/blog/md-architectural-overview) where the state of encryption ratchets is stored server-side. While it protects the user from their communication peers, it increases required level of trust to the servers, and in case of SimpleX network it would expose the knowledge of who communicates to whom. So while the idea of server-side storage of encryption state is promising, it has to be per-connection, to retain "no-accounts" property of SimpleX messaging network.
+
+Also see [FAQ](https://simplex.chat/faq/#why-cant-i-use-the-same-profile-on-different-devices) and [this issue](https://github.com/simplex-chat/simplex-chat/issues/444#issuecomment-3066968358).
+
+## Proposed solution
+
+One of the ideas presented in FAQ - to store the state of Double Ratchet algorithm in the encrypted container on the server seems promising. The RFC develops this idea.
+
+### Considerations for the design
+
+1. The largest ratchet state size with the current implementation is less than 8kb (which is achieved when both sides shared PQ keys and ciphertexts), so while it cannot fit in the same transport blocks together with sent and received messages, it would fit in one transport block.
+
+2. Protocol commands and events may be changed (even if at the cost of slightly reducing message size) can fit the hash of the ratchet state (32 bytes sha256 would be sufficient), so that the client can determine whether it has the most recent ratchet state or if it needs to retrieve the latest copy. Message size reduction won't affect the users because we use compression, and there is a substantial reserve.
+
+3. Client commands that modify ratchet state would include the hash of the previous ratchet state so that the server can reject or ignore the command in case the previous ratchet state is different or in case command is repeated in case of lost response).
+
+4. The client does not need to retrieve message state for each encryption and decryption operation - it can "speculatively" use the ratchet state it has, and receive correct ratchet state in the "error" response after attempting encryption based on incorrect ratchet state.
+
+## Proposed protocol design
+
+Ratchet state will be stored on the same server that stores message queue, as part of message queue record. 8kb is a sufficient size for this blob (the actual max size is 7800 bytes). The server would also store the hashes of the current and, possibly, the previous ratchet states (TBC).
+
+While ratchet is used for duplex connection, the connection still has primary queue, and with redundancy the same ratchet state can be stored on all secondary queues.
+
+Ratchet state will be encrypted using secret_box - a symmetric encryption scheme, so PQ-resistant. If ratchet state is stored on more than one server, it has to be encrypted with a different key for each server.
+
+Questions: how to rotate the key used to store ratchet? Should key used to encrypt ratchet rotate at the same time when queue is rotated? The latter is a logical option, as it prevents additional complexity and solves the problem anyway. A possible option is to have "ratchet version" that will be used to advance the key used to encrypt ratchet via HKDF.
+
+Security considerations: the scheme may reduce break-in recovery to the points queues are rotated, unless there is some randomness mixed-in into the key derivation (the key used to encrypt ratchet state). But including randomness would defeat the purpose, as other devices wouldn't be able to access the ratchets. Another approach would be to have each device use its own key for encryption, and encrypt to all keys of all devices (or to encrypt key, to avoid size increase). Having multiple encryptions would show how many devices use the queue, but servers already can observe it, so it is a better tradeoff. Another idea would be to rotate the key used to authorize queue commands - we already support multiple recipient keys, and it can be used for multi-device scenario. That would partially mitigate break-in attacks as the attacker who obtained the key from ratchet state would be able to decrypt it, but won't be able to decrypt it (the attacker collusion with the server is not mitigated). Yet another idea would be for each party (device) to share its private (or encapsulation) key and to have a symmetric key (used to encrypt the ratchet state) encrypted (encapsulated) separately for each device. This would reduce the size of the stored data to `ratchet size` + `encrypted key size` * N, so even in case of PQ encryption (e.g. sntrup) the size required to store the ratchet would be under transport block size, while limiting it to say 4-8 devices, which is sufficient.
+
+To participate in multi-device scheme the devices would join the usual group that will be used to share public (encapsulation) device keys and to communicate updates to conversations that were received by the currently "active" device. "Active" means the device that received or sent and processed the message, and while only one device can receive messages from a given queue, device "active" state may be determined per queue, allowing concurrent usage.
+
+The scheme must be resilient to state updates being lost, and in case of direct messages it would result in some messages not being shown (or shown as skipped), while conversation preference and profile updates can be re-requested from peers, while the current profile of the user would become the latest. Likewise, for groups state updates ca be requested from super-peers or for decentralized groups - from owners. Maintaining chat state consistency is an important consideration, but is not a focus of this RFC - the focus is managing message delivery and DR encryption for multiple devices. Other multi-device schemes have the same issues with state consistency. Partially, the profile state consistency can be improved by using a single shared queue (or set of queues) to store user's profile and chat preferences to synchronize profile updates asynchronously between the devices.
+
+## The protocol to send the message
+
+`rsi` - ratchet state on device `i`.
+
+`enc(rs)` - current authoritative ratchet state on the server.
+
+`pt` and `ct` - plaintext and ciphertext messages.
+
+Encryption is a state transition function ratchetEnc: `(ct, rs') = ratchetEnc(pt, rs)`.
+
+1. Device encrypts the message using the stored ratchet state: `(ct, rsi') = ratchetEnc(pt, rsi)`
+
+2. Device sends modified encrypted ratchet state and the hash of the previous encrypted state to the server that stores the queue: `RSET (hash(enc(rsi)), enc(rsi'))`.
+
+3. If the hash of the previous state matches state stored on the server (`hash(enc(rsi)) == hash(enc(rs))`), the server updates the state and responds with `ratchet_ok` (that may include the current state or it's hash, for validation). If the hash is different, the server responds with `bad_ratchet(enc(rs))` message that includes the correct ratchet state. These updates must be atomic. In this case device has to update the local ratchet state (provided it can decrypt it), and repeat encryption attempt. If device cannot decrypt the provided ratchet state, it means that the connection is disrupted (possibly, device is removed from device group, but missed the notifications).
+
+4. After successful state update in primary receiving queue, the device would update it in secondary receiving queues.
+
+5. Device sends encrypted message as usual, via proxy that must be different both from the server that stores the ratchet and from the destination server.
+
+6. Device broadcasts sent message and new ratchet state to other devices in the device group.
+
+This protocol is simple, and it minimizes requests when sending the message to one additional request to update ratchet state in most cases, only requiring two requests when device state was not updated via device group prior to message sending attempt.
+
+## The protocol to receive the message
+
+Decryption is also a state transition function: `(pt, rs') = ratchetDec(ct, rs)`
+
+1. Server sends the message to the device (can be in response to SUB or ACK commands, or with active subscription). Pushed message would include the hash of the currently stored ratchet state: `hash(enc(rs))`.
+
+2. If device has the ratchet state with the same hash (`hash(enc(rs)) == hash(enc(rsi))`), it decrypts the message: `(pt, rsi') = ratchetDec(ct, rsi)`.
+
+3. If device has ratchet state with a different hash, it requests ratchet from the server with additional protocol command `RGET` with response `RCHT (enc(rs))` and updates the local state.
+
+4. Device decrypts the message `(pt, rsi') = ratchetDec(ct, rsi)` and processes it as usual.
+
+5. Device sends acknowledgement to the server as usual, but now it includes the new ratchet state and the hash of the previous state: `ACK msgId (hash(enc(rsi)), enc(rsi'))`
+
+6. The server compares ratchet state with stored state hash, and in case it matches it processes `ACK` and responds with `OK` as usual (or `NO_MSG` in case msgId is incorrect, also as usual - it would happen in repeated ACK requests). If ratchet state hash does not match, the server would respond with `bad_ratchet(enc(rs))` - which means that the message was already processed by another device and ratchet was advanced. This is a complex scenario, as the client has to either revert the change from message processing or somehow combine the change with the updates communicated via device group (as a side note, device group can simply re-broadcast messages, not state updates, but it will result in state divergence between devices when different messages are lost).
+
+Unlike sending messages, this flow does not require any additional requests in most cases, only requiring requesting message state reconciliation when the same message was received and processed by more than one client, but it does not require re-acknowledgement.
+
+## Challenges
+
+This is an idea of the design rather than the actual design, as it requires more thinking about:
+- how to handle concurrent ratchet state updates,
+- "active" status transitions per queue,
+- avoiding concurrent subscriptions to queues from multiple devices,
+- state updates and synchronization between devices,
+- handling skipped messages,
+- costs to update ratchets in bulk send scenario - this scheme would substantially increase costs of preparing large broadcasts, and it makes this scheme not acceptable for chat relays. Which means that "profile" on desktop used as chat relay won't be synched to other devices.
+- etc.
+
+## Advantages
+
+The communication peers won't know how many devices the user has, and which device was used to send the message. Also, the communication peers won't be able to send different messages to different user's devices, or to withhold messages from some devices.

rfcs/2026-01-30-send-file-page/2026-01-31-xftp-web-server-changes.md

@@ -0,0 +1,154 @@
+# XFTP Server: SNI, CORS, and Web Support
+
+Implementation details for Phase 3 of `rfcs/2026-01-30-send-file-page.md` (sections 6.1-6.4).
+
+## 1. Overview
+
+The XFTP server is extended to support web browser clients by:
+
+1. **SNI-based TLS certificate switching** — Present a CA-issued web certificate (e.g., Let's Encrypt) to browsers, while continuing to present the self-signed XFTP identity certificate to native clients.
+2. **CORS headers** — Add CORS response headers on SNI connections so browsers allow cross-origin XFTP requests.
+3. **Configuration** — `[WEB]` INI section for HTTPS cert/key paths; opt-in (commented out by default).
+
+Web handshake (challenge-response identity proof, §6.3 of parent RFC) is not yet implemented and will be added separately.
+
+## 2. SNI Certificate Switching
+
+### 2.1 Reusing the SMP Pattern
+
+The SMP server already implements SNI-based certificate switching via `TLSServerCredential` and `runTransportServerState_` (see `rfcs/2024-09-15-shared-port.md`). The XFTP server applies the same pattern with one key difference: both native and web XFTP clients use HTTP/2 transport, whereas SMP switches between raw SMP protocol and HTTP entirely.
+
+### 2.2 Approach
+
+When `httpServerCreds` is configured, the XFTP server bypasses `runHTTP2Server` and uses `runTransportServerState_` directly to obtain the per-connection `sniUsed` flag. It then sets up HTTP/2 manually on each TLS connection using `withHTTP2` (same internals as `runHTTP2ServerWith_`). The `sniUsed` flag is captured in the closure and shared by all HTTP/2 requests on that connection.
+
+When `httpServerCreds` is absent, the existing `runHTTP2Server` path is unchanged.
+
+```
+Native client (no SNI)  ──TLS──> XFTP identity cert ──HTTP/2──> processRequest (no CORS)
+Browser client (SNI)    ──TLS──> Web CA cert        ──HTTP/2──> processRequest (+ CORS)
+```
+
+### 2.3 Certificate Chain
+
+The web certificate file (e.g., `web.crt`) must contain the full chain: leaf certificate followed by the signing CA certificate. `loadServerCredential` uses `T.credentialLoadX509Chain` which reads all PEM blocks from the file.
+
+The client validates the chain by comparing `idCert` fingerprint (the CA cert, second in the 2-cert chain) against the known `keyHash`. This is the same validation as for XFTP identity certificates — the CA that signed the web cert must match the XFTP server's identity.
+
+## 3. CORS Support
+
+### 3.1 Design
+
+CORS headers are only added when both conditions are true:
+- `addCORSHeaders` is `True` in `TransportServerConfig` (set in XFTP `Main.hs`)
+- `sniUsed` is `True` for the current TLS connection
+
+This ensures native clients never see CORS headers.
+
+### 3.2 Response Headers
+
+All POST responses on SNI connections include:
+```
+Access-Control-Allow-Origin: *
+Access-Control-Expose-Headers: *
+```
+
+### 3.3 OPTIONS Preflight
+
+OPTIONS requests are intercepted at the HTTP/2 dispatch level, before `processRequest`. This is necessary because `processRequest` rejects bodies that don't match `xftpBlockSize`.
+
+Preflight response:
+```
+HTTP/2 200
+Access-Control-Allow-Origin: *
+Access-Control-Allow-Methods: POST, OPTIONS
+Access-Control-Allow-Headers: *
+Access-Control-Max-Age: 86400
+```
+
+### 3.4 Security
+
+`Access-Control-Allow-Origin: *` is safe because:
+- All XFTP commands require Ed25519 authentication (per-chunk keys from file description).
+- No cookies or browser credentials are involved.
+- File content is end-to-end encrypted.
+
+## 4. Configuration
+
+### 4.1 INI Template
+
+```ini
+[WEB]
+# cert: /etc/opt/simplex-xftp/web.crt
+# key: /etc/opt/simplex-xftp/web.key
+```
+
+Commented out by default — web support is opt-in.
+
+### 4.2 Behavior
+
+- `[WEB]` section not configured: silently ignored, server operates normally for native clients only.
+- `[WEB]` section configured with valid cert/key paths: SNI + CORS enabled.
+- `[WEB]` section configured with missing cert files: warning + continue (non-fatal, unlike SMP where it is fatal).
+
+## 5. Files Modified
+
+### 5.1 `src/Simplex/Messaging/Transport/Server.hs`
+
+Added `addCORSHeaders :: Bool` field to `TransportServerConfig`. Updated `mkTransportServerConfig` to accept the new parameter. All existing SMP call sites pass `False`.
+
+### 5.2 `src/Simplex/Messaging/Transport/HTTP2/Server.hs`
+
+- Extracted `expireInactiveClient` from `runHTTP2ServerWith_`'s `where` clause to a module-level function.
+- Parameterized `runHTTP2ServerWith_`: setup type changed from `((TLS p -> IO ()) -> a)` to `(((Bool, TLS p) -> IO ()) -> a)`, callback from `HTTP2ServerFunc` to `Bool -> HTTP2ServerFunc`. The `Bool` is the per-connection `sniUsed` flag, threaded through `H.run` to the callback.
+- Extended `runHTTP2Server` with `Maybe T.Credential` parameter for SNI web certificate. Its setup uses `runTransportServerState_` with `TLSServerCredential`, which naturally provides `(sniUsed, tls)` pairs matching the new `runHTTP2ServerWith_` setup type.
+- Adapted `runHTTP2ServerWith` (client-side HTTP/2, no SNI): wraps its setup to inject `(False, tls)` and its callback with `const`.
+- Updated `getHTTP2Server` (test helper) to pass `Nothing` for httpCreds.
+
+### 5.3 `src/Simplex/FileTransfer/Server/Env.hs`
+
+- Added `httpCredentials :: Maybe ServerCredentials` to `XFTPServerConfig`.
+- Added `httpServerCreds :: Maybe T.Credential` to `XFTPEnv`.
+- `newXFTPServerEnv` loads HTTP credentials when configured.
+
+### 5.4 `src/Simplex/FileTransfer/Server/Main.hs`
+
+- Added `[WEB]` section to INI template.
+- Added `httpCredentials` parsing from INI `[WEB]` section (`cert` and `key` fields).
+- Set `addCORSHeaders = isJust httpCredentials_` in transport config (conditional on web cert presence).
+
+### 5.5 `src/Simplex/FileTransfer/Server.hs`
+
+Core server changes:
+
+- `runServer` calls `runHTTP2Server` with `httpCreds_` and a `\sniUsed -> handleRequest (sniUsed && addCORSHeaders transportConfig)` callback. TLS params are `defaultSupportedParamsHTTPS` when web creds present, `defaultSupportedParams` otherwise. SNI routing, HTTP/2 setup, and client expiration are handled inside `runHTTP2Server`.
+
+- `XFTPTransportRequest` carries `addCORS :: Bool` field, threaded through to `sendXFTPResponse`.
+
+- `sendXFTPResponse` conditionally includes CORS headers based on `addCORS`.
+
+- OPTIONS requests on SNI connections return CORS preflight headers before reaching `processRequest`.
+
+- Helper functions: `corsHeaders` (response headers), `corsPreflightHeaders` (preflight headers).
+
+### 5.6 `tests/XFTPClient.hs`
+
+- Added `httpCredentials = Nothing` to `testXFTPServerConfig`.
+- Added `testXFTPServerConfigSNI` with web cert config and `addCORSHeaders = True`.
+- Added `withXFTPServerSNI` helper.
+
+### 5.7 `tests/XFTPServerTests.hs`
+
+Added SNI and CORS tests as a subsection within `xftpServerTests` (6 tests):
+
+1. **SNI cert selection** — Connect with SNI + `h2` ALPN, verify RSA web certificate is presented.
+2. **Non-SNI cert selection** — Connect without SNI + `xftp/1` ALPN, verify Ed448 XFTP certificate is presented.
+3. **CORS headers** — SNI POST request includes `Access-Control-Allow-Origin: *` and `Access-Control-Expose-Headers: *`.
+4. **OPTIONS preflight** — SNI OPTIONS request returns all CORS preflight headers.
+5. **No CORS without SNI** — Non-SNI POST request has no CORS headers.
+6. **File chunk delivery** — Full XFTP file chunk upload/download through SNI-enabled server verifying no regression.
+
+## 6. Remaining Work
+
+- **Web handshake** (§6.3 of parent RFC): Challenge-response identity proof for SNI connections. The server detects web clients via the `sniUsed` flag and expects a 32-byte challenge in the first POST body (non-empty, unlike standard handshake). Response includes full cert chain + signature over `(challenge ++ sessionId)`.
+- **Static page serving** (§6.5 of parent RFC): Optional serving of the web page HTML/JS bundle on GET requests.

rfcs/2026-01-30-send-file-page/2026-02-02-xftp-web-handshake.md

@@ -0,0 +1,246 @@
+# Web Handshake — Challenge-Response Identity Proof
+
+RFC §6.3: Server proves XFTP identity to web clients independently of TLS CA infrastructure.
+
+## 1. Protocol
+
+**Standard handshake** (unchanged):
+```
+Client → empty POST                                        → Server
+Server → padded {vRange, sessionId, authPubKey, Nothing}    → Client
+Client → padded {version, keyHash, Nothing}                 → Server
+Server → empty                                              → Client
+```
+
+**Web handshake** (SNI connection, non-empty hello):
+```
+Client → padded {32 random bytes}                                → Server
+Server → padded {vRange, sessionId, authPubKey, Just sigBytes}   → Client
+  sigBytes = signatureBytes(sign(identityLeafKey, challenge <> sessionId))
+Client validates:
+  1. chainIdCaCerts(authPubKey.certChain) → CCValid {leafCert, idCert}
+  2. SHA-256(idCert) == keyHash   (server identity)
+  3. verify(leafCert.pubKey, sigBytes, challenge <> sessionId)  (challenge-response)
+  4. verify(leafCert.pubKey, signedPubKey.signature, signedPubKey.objectDer)  (DH key auth)
+Client → padded {version, keyHash, Just challenge}               → Server
+Server verifies: echoed challenge == stored challenge from step 1
+Server → empty                                                   → Client
+```
+
+**Detection**: `sniUsed` per-connection flag. Non-empty hello allowed only when `sniUsed`. Empty hello with SNI → standard handshake.
+
+**Why both steps 3 and 4**: Native clients verify `signedPubKey` using the TLS peer certificate (`serverKey` from `getServerVerifyKey`), which is the XFTP identity cert in non-SNI connections — TLS provides this binding. Web clients cannot access TLS peer certificate data (browser API limitation; TLS presents the web CA cert but provides no API to extract it). So web clients must verify at the application layer using `authPubKey.certChain`, which always contains the XFTP identity chain regardless of which cert TLS used. Step 3 proves the server holds its identity key *right now* (freshness via random challenge). Step 4 proves the DH session key was signed by the identity key holder (prevents MITM key substitution). Together they give web clients some assurance native clients get from TLS, except channel binding for commands.
+
+## 2. Type Changes — `src/Simplex/FileTransfer/Transport.hs`
+
+### `XFTPServerHandshake` (line 114)
+
+Add field: `webIdentityProof :: Maybe ByteString` — raw Ed448 signature bytes (114 bytes), or `Nothing` for standard handshake. No record needed — the cert chain is already in `authPubKey.certChain`.
+
+### `Encoding XFTPServerHandshake` (line 136)
+
+- `smpEncode`: append `smpEncode webIdentityProof`
+- `smpP`: `Tail compat`, if non-empty `eitherToMaybe $ smpDecode compat`
+
+Backward compat: old clients ignore via `Tail _compat`; new client + old server → empty compat → `Nothing`.
+
+### `XFTPClientHandshake` (line 121)
+
+Add field: `webChallenge :: Maybe ByteString`
+
+### `Encoding XFTPClientHandshake` (line 128)
+
+Same `Tail compat` pattern as server handshake.
+
+### Export list
+
+Both types use `(..)` export — new fields auto-exported.
+
+## 3. Server Changes — `src/Simplex/FileTransfer/Server.hs`
+
+### `XFTPTransportRequest` (line 88)
+
+Add field: `sniUsed :: SNICredentialUsed` (`Bool` from `Transport.Server`). Add import.
+
+### `Handshake` (line 117)
+
+`HandshakeSent C.PrivateKeyX25519` → `HandshakeSent C.PrivateKeyX25519 (Maybe ByteString)` — stores 32-byte web challenge or `Nothing`.
+
+### `runServer` handler (line 145–161)
+
+- Pass `sniUsed` into request construction (line 154)
+- SNI-first routing: when `sniUsed`, always route to `xftpServerHandshakeV1` (web ALPN `h2` would otherwise fall to `_` catch-all)
+
+### `xftpServerHandshakeV1` (line 162)
+
+- Destructure `sniUsed` from request
+- Match `HandshakeSent pk challenge_` → `processClientHandshake pk challenge_`
+
+### `processHello` (line 171)
+
+- Branch `(sniUsed, B.null bodyHead)`:
+  - `(_, True)` → standard: `challenge_ = Nothing`
+  - `(True, False)` → web: unpad, verify 32 bytes, `challenge_ = Just`
+  - `(False, False)` → `throwE HANDSHAKE`
+- Store: `HandshakeSent pk challenge_`
+- Compute: `webIdentityProof = C.signatureBytes . C.sign serverSignKey . (<> sessionId) <$> challenge_`
+- Construct `XFTPServerHandshake` with `webIdentityProof`
+
+### `processClientHandshake` (line 183)
+
+- Accept `challenge_` parameter
+- Decode `webChallenge` from `XFTPClientHandshake`
+- Add: `unless (challenge_ == webChallenge) $ throwE HANDSHAKE`
+  (standard: both `Nothing` → passes)
+
+## 4. Native Client — `src/Simplex/FileTransfer/Client.hs`
+
+### `xftpClientHandshakeV1` (line 142)
+
+Add `webChallenge = Nothing` in `sendClientHandshake` call.
+
+No other changes — parser handles new fields via `Tail`, native client ignores `webIdentityProof`.
+
+## 5. TypeScript Changes (DONE except Ed448)
+
+Sections 5.1 and 5.2 are implemented. Section 5.3 needs Ed448 support.
+
+## 10. Ed448 Support via `@noble/curves`
+
+**Problem**: Production servers use Ed448 certificates (default). `identity.ts` only supports Ed25519 via libsodium. libsodium has no Ed448 support and never will.
+
+**Solution**: Add `@noble/curves` dependency for Ed448 verification only. All other crypto stays with libsodium.
+
+### 10.1 `xftp-web/package.json` — Add dependency
+
+```json
+"dependencies": {
+  "libsodium-wrappers-sumo": "^0.7.13",
+  "@noble/curves": "^1.9.7"
+}
+```
+
+Use v1.x (supports both CJS and ESM). v2.x is ESM-only with `.js` extension requirement.
+
+### 10.2 `xftp-web/src/crypto/keys.ts` — Ed448 DER constants and decode
+
+Add Ed448 SPKI DER prefix (12 bytes, same prefix length as Ed25519):
+```
+30 43 30 05 06 03 2b 65 71 03 3a 00
+```
+
+| Property | Ed25519 | Ed448 |
+|----------|---------|-------|
+| OID | `2b 65 70` | `2b 65 71` |
+| SPKI prefix | `30 2a ...` | `30 43 ...` |
+| Raw key size | 32 bytes | 57 bytes |
+| SPKI total | 44 bytes | 69 bytes |
+| Signature size | 64 bytes | 114 bytes |
+
+New functions:
+- `decodePubKeyEd448(der: Uint8Array): Uint8Array` — 69 bytes → 57 bytes raw
+- `encodePubKeyEd448(raw: Uint8Array): Uint8Array` — 57 bytes → 69 bytes DER
+- `verifyEd448(publicKey: Uint8Array, sig: Uint8Array, msg: Uint8Array): boolean` — uses `ed448.verify(sig, msg, publicKey)` from `@noble/curves/ed448`
+
+Note: `@noble/curves` parameter order is `(signature, message, publicKey)`, not `(publicKey, signature, message)`.
+
+### 10.3 `xftp-web/src/crypto/identity.ts` — Algorithm-agnostic verification
+
+Replace `extractCertEd25519Key` + hardcoded Ed25519 `verify` with algorithm detection:
+
+1. `extractCertPublicKeyInfo(certDer)` → SPKI DER (already exists, works for any algorithm)
+2. Detect algorithm from SPKI: byte at offset 8 is `0x70` (Ed25519) or `0x71` (Ed448)
+3. Extract raw key with appropriate decoder
+4. Verify signatures with appropriate function
+
+```typescript
+type CertKeyAlgorithm = 'ed25519' | 'ed448'
+
+function detectKeyAlgorithm(spki: Uint8Array): CertKeyAlgorithm {
+  if (spki.length === 44 && spki[8] === 0x70) return 'ed25519'
+  if (spki.length === 69 && spki[8] === 0x71) return 'ed448'
+  throw new Error("unsupported certificate key algorithm")
+}
+```
+
+`verifyIdentityProof` changes:
+- Extract SPKI from leaf cert
+- Detect algorithm → choose `decodePubKeyEd25519`/`decodePubKeyEd448` and `verify`/`verifyEd448`
+- Both challenge signature and DH key signature use the same leaf key + algorithm
+
+Remove `extractCertEd25519Key` (replaced by generic path). Keep `extractCertPublicKeyInfo` (already generic).
+
+### 10.4 `xftp-web/src/protocol/handshake.ts` — Comment update
+
+`SignedKey.signature` comment: "raw Ed25519 signature bytes (64 bytes)" → "raw signature bytes (Ed25519: 64, Ed448: 114)"
+
+### 10.5 Tests — `tests/XFTPWebTests.hs`
+
+**Integration test**: Switch from `withXFTPServerEd25519SNI` (Ed25519 fixtures) to `withXFTPServerSNI` (default Ed448 fixtures). Update fingerprint source from `tests/fixtures/ed25519/ca.crt` to `tests/fixtures/ca.crt`.
+
+Optionally add a second integration test with Ed25519 to cover both paths, or rely on existing unit tests for Ed25519 coverage.
+
+### 10.6 Implementation order
+
+1. `npm install @noble/curves` in `xftp-web/`
+2. `keys.ts` — Ed448 constants, decode, encode, verifyEd448
+3. `identity.ts` — algorithm detection, generic verification
+4. `handshake.ts` — comment fix
+5. `XFTPWebTests.hs` — switch integration test to Ed448
+6. Build TS + run all tests
+
+## 6. Haskell Integration Test — `tests/XFTPServerTests.hs`
+
+Add `testWebHandshake` to "XFTP SNI and CORS" describe block.
+
+1. `withXFTPServerSNI` — server with web credentials
+2. Connect with SNI + `h2` ALPN
+3. Send padded 32-byte challenge
+4. Decode `XFTPServerHandshake`, assert `webIdentityProof` is `Just`
+5. `chainIdCaCerts` on `authPubKey.certChain` → `CCValid {leafCert, idCert}`
+6. Verify `SHA-256(idCert) == keyHash`
+7. Extract `leafCert` public key, verify challenge signature
+8. Verify `signedPubKey` signature using `leafCert` key (DH key auth)
+9. Send `XFTPClientHandshake` with `webChallenge = Just challenge`
+10. Assert empty response
+
+Imports: `XFTPServerHandshake (..)`, `XFTPClientHandshake (..)`, `ChainCertificates (..)`, `chainIdCaCerts`.
+
+## 7. TS Tests — `tests/XFTPWebTests.hs`
+
+### Unit tests
+
+- **`decodeServerHandshake` with proof**: Haskell-encode with `Just sigBytes`, TS-decode, verify bytes match.
+- **`encodeClientHandshake` with challenge**: TS-encode, compare with Haskell-encoded.
+- **`chainIdCaCerts`**: 2/3/4-cert chains return correct positions.
+- **`caFingerprint` (fixed)**: matches `sha256(idCert)` for 2 and 3-cert chains.
+
+### Integration test
+
+Node.js inline script against `withXFTPServerSNI`:
+1. Connect with SNI via `http2.connect`
+2. Send padded challenge, decode `XFTPServerHandshake` with TS
+3. `verifyIdentityProof` — full chain validation + challenge sig + DH key sig
+4. Send client handshake with echoed challenge
+5. Assert empty response
+
+## 8. Implementation Order
+
+1. `Transport.hs` — `Maybe` fields + encoding instances
+2. `Server.hs` — `sniUsed`, challenge in `Handshake`, `processHello`, `processClientHandshake`, SNI routing
+3. `Client.hs` — `webChallenge = Nothing`
+4. Build: `cabal build --ghc-options -O0`
+5. Run existing SNI/CORS tests
+6. `XFTPServerTests.hs` — `testWebHandshake`
+7. `handshake.ts` — types, decoding, `chainIdCaCerts`, fix `caFingerprint`
+8. `crypto/identity.ts` — Node.js verification functions
+9. `XFTPWebTests.hs` — unit + integration tests
+10. Build TS + run all tests
+
+## 9. Verification
+
+```bash
+cd xftp-web && npm install && npm run build && cd ..
+cabal test --ghc-options=-O0 --test-option='--match=/XFTP/XFTP server/XFTP SNI and CORS/' --test-show-details=streaming
+cabal test --ghc-options=-O0 --test-option='--match=/XFTP Web Client/' --test-show-details=streaming
+```

rfcs/2026-01-30-send-file-page/2026-02-03-xftp-web-browser-tests.md

@@ -0,0 +1,208 @@
+# Plan: Browser ↔ Haskell File Transfer Tests
+
+## Table of Contents
+1. Goal
+2. Current State
+3. Implementation
+4. Success Criteria
+5. Files
+6. Order
+
+## 1. Goal
+Run browser upload/download tests in headless Chromium via Vitest, proving fetch-based transport works in real browser environment.
+
+## 2. Current State
+- `client.ts`: Transport abstraction done — http2 for Node, fetch for browser ✓
+- `agent.ts`: Uses `node:crypto` (randomBytes) and `node:zlib` (deflateRawSync/inflateRawSync) — **won't run in browser**
+- `XFTPWebTests.hs`: Cross-language tests exist (Haskell calls TS via Node.js) ✓
+
+## 3. Implementation
+
+### 3.1 Make agent.ts isomorphic
+
+| Current (Node.js only) | Isomorphic replacement |
+|------------------------|------------------------|
+| `import crypto from "node:crypto"` | Remove import |
+| `import zlib from "node:zlib"` | `import pako from "pako"` |
+| `crypto.randomBytes(32)` | `crypto.getRandomValues(new Uint8Array(32))` |
+| `zlib.deflateRawSync(buf)` | `pako.deflateRaw(buf)` |
+| `zlib.inflateRawSync(buf)` | `pako.inflateRaw(buf)` |
+
+Note: `crypto.getRandomValues` available in both browser and Node.js (globalThis.crypto).
+
+### 3.2 Vitest browser mode setup
+
+`package.json` additions:
+```json
+"devDependencies": {
+  "vitest": "^3.0.0",
+  "@vitest/browser": "^3.0.0",
+  "playwright": "^1.50.0",
+  "@types/pako": "^2.0.3"
+},
+"dependencies": {
+  "pako": "^2.1.0"
+}
+```
+
+`vitest.config.ts`:
+```typescript
+import {defineConfig} from 'vitest/config'
+import {readFileSync} from 'fs'
+import {createHash} from 'crypto'
+
+// Compute fingerprint from ca.crt (same as Haskell's loadFileFingerprint)
+const caCert = readFileSync('../tests/fixtures/ca.crt')
+const fingerprint = createHash('sha256').update(caCert).digest('base64url')
+const serverAddr = `xftp://${fingerprint}@localhost:7000`
+
+export default defineConfig({
+  define: {
+    'import.meta.env.XFTP_SERVER': JSON.stringify(serverAddr)
+  },
+  test: {
+    browser: {
+      enabled: true,
+      provider: 'playwright',
+      instances: [{browser: 'chromium'}],
+      headless: true,
+      providerOptions: {
+        launch: {ignoreHTTPSErrors: true}
+      }
+    },
+    globalSetup: './test/globalSetup.ts'
+  }
+})
+```
+
+### 3.3 Server startup
+
+`test/globalSetup.ts`:
+```typescript
+import {spawn, ChildProcess} from 'child_process'
+import {resolve, join} from 'path'
+import {mkdtempSync, writeFileSync, copyFileSync} from 'fs'
+import {tmpdir} from 'os'
+
+let server: ChildProcess | null = null
+
+export async function setup() {
+  const fixtures = resolve(__dirname, '../../tests/fixtures')
+
+  // Create temp directories
+  const cfgDir = mkdtempSync(join(tmpdir(), 'xftp-cfg-'))
+  const logDir = mkdtempSync(join(tmpdir(), 'xftp-log-'))
+  const filesDir = mkdtempSync(join(tmpdir(), 'xftp-files-'))
+
+  // Copy certificates to cfgDir (xftp-server expects ca.crt, server.key, server.crt there)
+  copyFileSync(join(fixtures, 'ca.crt'), join(cfgDir, 'ca.crt'))
+  copyFileSync(join(fixtures, 'server.key'), join(cfgDir, 'server.key'))
+  copyFileSync(join(fixtures, 'server.crt'), join(cfgDir, 'server.crt'))
+
+  // Write INI config file
+  const iniContent = `[STORE_LOG]
+enable: off
+
+[TRANSPORT]
+host: localhost
+port: 7000
+
+[FILES]
+path: ${filesDir}
+
+[WEB]
+cert: ${join(fixtures, 'web.crt')}
+key: ${join(fixtures, 'web.key')}
+`
+  writeFileSync(join(cfgDir, 'file-server.ini'), iniContent)
+
+  // Spawn xftp-server with env vars
+  server = spawn('cabal', ['exec', 'xftp-server', '--', 'start'], {
+    env: {
+      ...process.env,
+      XFTP_SERVER_CFG_PATH: cfgDir,
+      XFTP_SERVER_LOG_PATH: logDir
+    },
+    stdio: ['ignore', 'pipe', 'pipe']
+  })
+
+  // Wait for "Listening on port 7000..."
+  await waitForServerReady(server)
+}
+
+export async function teardown() {
+  server?.kill('SIGTERM')
+  await new Promise(r => setTimeout(r, 500))
+}
+
+function waitForServerReady(proc: ChildProcess): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => reject(new Error('Server start timeout')), 15000)
+    proc.stdout?.on('data', (data: Buffer) => {
+      if (data.toString().includes('Listening on port')) {
+        clearTimeout(timeout)
+        resolve()
+      }
+    })
+    proc.stderr?.on('data', (data: Buffer) => {
+      console.error('[xftp-server]', data.toString())
+    })
+    proc.on('error', reject)
+    proc.on('exit', (code) => {
+      clearTimeout(timeout)
+      if (code !== 0) reject(new Error(`Server exited with code ${code}`))
+    })
+  })
+}
+```
+
+Server env vars (from `apps/xftp-server/Main.hs` + `getEnvPath`):
+- `XFTP_SERVER_CFG_PATH` — directory containing `file-server.ini` and certs (`ca.crt`, `server.key`, `server.crt`)
+- `XFTP_SERVER_LOG_PATH` — directory for logs
+
+### 3.4 Browser test
+
+`test/browser.test.ts`:
+```typescript
+import {test, expect} from 'vitest'
+import {encryptFileForUpload, uploadFile, downloadFile} from '../src/agent.js'
+import {parseXFTPServer} from '../src/protocol/address.js'
+
+const server = parseXFTPServer(import.meta.env.XFTP_SERVER)
+
+test('browser upload + download round-trip', async () => {
+  const data = new Uint8Array(50000)
+  crypto.getRandomValues(data)
+  const encrypted = encryptFileForUpload(data, 'test.bin')
+  const {rcvDescription} = await uploadFile(server, encrypted)
+  const {content} = await downloadFile(rcvDescription)
+  expect(content).toEqual(data)
+})
+```
+
+## 4. Success Criteria
+
+1. `npm run build` — agent.ts compiles without node: imports
+2. `cabal test --test-option='--match=/XFTP Web Client/'` — existing Node.js tests still pass
+3. `npm run test:browser` — browser round-trip test passes in headless Chromium
+
+## 5. Files to Create/Modify
+
+**Modify:**
+- `xftp-web/package.json` — add vitest, @vitest/browser, playwright, pako, @types/pako
+- `xftp-web/src/agent.ts` — replace node:crypto, node:zlib with isomorphic alternatives
+
+**Create:**
+- `xftp-web/vitest.config.ts` — browser mode config
+- `xftp-web/test/globalSetup.ts` — xftp-server lifecycle
+- `xftp-web/test/browser.test.ts` — browser round-trip test
+
+## 6. Order of Implementation
+
+1. **Add pako dependency** — `npm install pako @types/pako`
+2. **Make agent.ts isomorphic** — replace node:crypto, node:zlib
+3. **Verify Node.js tests pass** — `cabal test --test-option='--match=/XFTP Web Client/'`
+4. **Set up Vitest** — add devDeps, create vitest.config.ts
+5. **Create globalSetup.ts** — write INI config, spawn xftp-server
+6. **Write browser test** — upload + download round-trip
+7. **Verify browser test passes** — `npm run test:browser`

rfcs/2026-01-30-send-file-page/2026-02-04-xftp-web-browser-transport.md

@@ -0,0 +1,920 @@
+# Browser Transport & Web Worker Architecture
+
+## TOC
+
+1. Executive Summary
+2. Transport: fetch() API
+3. Architecture: Environment Abstraction
+4. Web Worker Implementation
+5. OPFS Implementation
+6. Implementation Plan
+7. Testing Strategy
+
+## 1. Executive Summary
+
+Adapt `client.ts` from `node:http2` to `fetch()` API for isomorphic Node.js/browser support. Add environment abstraction layer so the same upload/download pipeline works with or without Web Workers and with or without OPFS. In browsers, crypto runs in a Web Worker to keep UI responsive; in Node.js tests, crypto runs directly.
+
+**Key architectural constraint:** Existing crypto functions (`encryptFile`, `decryptChunks`, etc.) remain unchanged. The abstraction layer wraps them, choosing execution context (direct vs Worker) and storage (memory vs OPFS) based on environment.
+
+**Scope:**
+- Replace `node:http2` with `fetch()` in `client.ts`
+- Add `CryptoBackend` abstraction with three implementations
+- Create Web Worker that calls existing crypto functions
+- Add OPFS storage for large files in browser
+
+**Out of scope:** Web page UI (Phase 5 in main RFC).
+
+## 2. Transport: fetch() API
+
+### 2.1 Current State
+
+`client.ts` uses `node:http2`:
+```typescript
+import http2 from "node:http2"
+const session = http2.connect(url)
+const stream = session.request({':method': 'POST', ':path': '/'})
+stream.write(commandBlock)
+stream.end(chunkData)
+```
+
+### 2.2 Target State
+
+Isomorphic `fetch()` (Node.js 18+ and browsers):
+```typescript
+const response = await fetch(url, {
+  method: 'POST',
+  body: concatStreams(commandBlock, chunkData),
+  duplex: 'half',  // Required for streaming request body
+})
+const reader = response.body!.getReader()
+```
+
+### 2.3 Key Differences
+
+| Aspect | node:http2 | fetch() |
+|--------|-----------|---------|
+| Session management | Explicit `session.connect()` / `session.close()` | Per-request (HTTP/2 connection reuse is automatic) |
+| Streaming upload | `stream.write()` chunks | `ReadableStream` body + `duplex: 'half'` |
+| Streaming download | `stream.on('data')` | `response.body.getReader()` |
+| Connection pooling | Manual | Automatic per origin |
+
+### 2.4 API Changes
+
+```typescript
+// Before (node:http2)
+export interface XFTPClient {
+  session: http2.ClientHttp2Session
+  thParams: THParams
+  server: XFTPServer
+}
+
+// After (fetch)
+export interface XFTPClient {
+  baseUrl: string           // "https://host:port"
+  thParams: THParams
+  server: XFTPServer
+}
+```
+
+`connectXFTP()` performs handshake via fetch, returns `XFTPClient` with `baseUrl`.
+Subsequent commands use `fetch(client.baseUrl, ...)`.
+
+### 2.5 Handshake via fetch()
+
+**TLS session binding:** Multiple fetch() requests to the same origin reuse the HTTP/2 connection, which means they share the same TLS session. The server's `sessionId` (derived from TLS channel binding) remains consistent across the handshake round-trips and subsequent commands.
+
+```typescript
+async function connectXFTP(server: XFTPServer): Promise<XFTPClient> {
+  const baseUrl = `https://${server.host}:${server.port}`
+
+  // Round-trip 1: challenge → server handshake + identity proof
+  const challenge = crypto.getRandomValues(new Uint8Array(32))
+  const req1 = pad(encodeWebClientHello(challenge), xftpBlockSize)
+  const resp1 = await fetch(baseUrl, {method: 'POST', body: req1})
+
+  const reader = resp1.body!.getReader()
+  const serverBlock = await readExactly(reader, xftpBlockSize)
+  const serverHs = decodeServerHandshake(unPad(serverBlock))
+  const proofBody = await readRemaining(reader)
+  verifyIdentityProof(server.keyHash, challenge, serverHs.sessionId, proofBody)
+
+  // Round-trip 2: client handshake → server ack
+  const clientHs = encodeClientHandshake({xftpVersion: 3, keyHash: server.keyHash})
+  const req2 = pad(clientHs, xftpBlockSize)
+  await fetch(baseUrl, {method: 'POST', body: req2})
+
+  return {baseUrl, thParams: {sessionId: serverHs.sessionId, ...}, server}
+}
+```
+
+### 2.6 Command Execution
+
+```typescript
+async function sendXFTPCommand(
+  client: XFTPClient,
+  key: Uint8Array,
+  entityId: Uint8Array,
+  cmd: Uint8Array,
+  chunkData?: Uint8Array
+): Promise<{response: Uint8Array, body?: ReadableStream}> {
+  const block = xftpEncodeAuthTransmission(client.thParams, key, entityId, cmd)
+
+  const reqBody = chunkData
+    ? concatBytes(block, chunkData)
+    : block
+
+  const resp = await fetch(client.baseUrl, {
+    method: 'POST',
+    body: reqBody,
+    duplex: 'half',
+  })
+
+  const reader = resp.body!.getReader()
+  const responseBlock = await readExactly(reader, xftpBlockSize)
+  const parsed = xftpDecodeTransmission(responseBlock)
+
+  // For FGET: remaining body is encrypted chunk
+  const hasMore = await peekReader(reader)
+  return {
+    response: parsed,
+    body: hasMore ? wrapAsStream(reader) : undefined
+  }
+}
+```
+
+## 3. Architecture: Environment Abstraction
+
+### 3.1 Core Principle
+
+**Existing crypto functions remain unchanged.** The functions `encryptFile()`, `decryptChunks()`, `sha512()`, etc. in `crypto/file.ts` and `crypto/digest.ts` are pure computation — they take input bytes and produce output bytes. They have no knowledge of Workers, OPFS, or execution context.
+
+The abstraction layer sits between `agent.ts` (upload/download orchestration) and these crypto functions:
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│  agent.ts (upload/download orchestration)                            │
+│  - Unchanged logic: encrypt → chunk → upload → build description     │
+│  - Calls CryptoBackend interface, not crypto functions directly      │
+├─────────────────────────────────────────────────────────────────────┤
+│  CryptoBackend interface (env.ts)                                    │
+│  - Abstract interface for encrypt/decrypt/readChunk/writeChunk       │
+│  - Factory function selects implementation based on environment      │
+├──────────────┬──────────────────────┬───────────────────────────────┤
+│ DirectMemory │ WorkerMemory         │ WorkerOPFS                    │
+│ Backend      │ Backend              │ Backend                       │
+│ (Node.js)    │ (Browser, ≤50MB)     │ (Browser, >50MB)              │
+├──────────────┼──────────────────────┼───────────────────────────────┤
+│ Calls crypto │ Posts to Worker,     │ Posts to Worker,              │
+│ functions    │ Worker calls crypto  │ Worker calls crypto,          │
+│ directly     │ functions, returns   │ streams through OPFS          │
+│              │ via postMessage      │                               │
+├──────────────┴──────────────────────┴───────────────────────────────┤
+│  crypto/file.ts, crypto/digest.ts (unchanged)                        │
+│  - encryptFile(), decryptChunks(), sha512(), etc.                    │
+│  - Pure functions, no environment dependencies                       │
+└─────────────────────────────────────────────────────────────────────┘
+```
+
+### 3.2 CryptoBackend Interface
+
+```typescript
+// env.ts
+export interface CryptoBackend {
+  // Encrypt file, store result (in memory or OPFS depending on backend)
+  encrypt(
+    data: Uint8Array,
+    fileName: string,
+    onProgress?: (done: number, total: number) => void
+  ): Promise<EncryptResult>
+
+  // Decrypt from stored encrypted data
+  decrypt(
+    key: Uint8Array,
+    nonce: Uint8Array,
+    size: number,
+    onProgress?: (done: number, total: number) => void
+  ): Promise<DecryptResult>
+
+  // Read chunk from stored encrypted data (for upload)
+  readChunk(offset: number, size: number): Promise<Uint8Array>
+
+  // Write chunk to storage (for download, before decrypt)
+  writeChunk(data: Uint8Array, offset: number): Promise<void>
+
+  // Clean up temporary storage
+  cleanup(): Promise<void>
+}
+
+export interface EncryptResult {
+  digest: Uint8Array      // SHA-512 of encrypted data
+  key: Uint8Array         // Generated encryption key
+  nonce: Uint8Array       // Generated nonce
+  chunkSizes: number[]    // Chunk sizes for upload
+  totalSize: number       // Total encrypted size
+}
+
+export interface DecryptResult {
+  header: FileHeader      // Extracted file header (fileName, etc.)
+  content: Uint8Array     // Decrypted file content
+}
+```
+
+### 3.3 Backend Implementations
+
+**DirectMemoryBackend** (Node.js):
+```typescript
+class DirectMemoryBackend implements CryptoBackend {
+  private encryptedData: Uint8Array | null = null
+
+  async encrypt(data: Uint8Array, fileName: string, onProgress?): Promise<EncryptResult> {
+    const key = randomBytes(32)
+    const nonce = randomBytes(24)
+    // Call existing crypto function directly
+    this.encryptedData = encryptFile(data, fileName, key, nonce, onProgress)
+    const digest = sha512(this.encryptedData)
+    const chunkSizes = prepareChunkSizes(this.encryptedData.length)
+    return { digest, key, nonce, chunkSizes, totalSize: this.encryptedData.length }
+  }
+
+  async decrypt(key, nonce, size, onProgress): Promise<DecryptResult> {
+    // Call existing crypto function directly
+    return decryptChunks([this.encryptedData!], key, nonce, size, onProgress)
+  }
+
+  async readChunk(offset: number, size: number): Promise<Uint8Array> {
+    return this.encryptedData!.slice(offset, offset + size)
+  }
+
+  async writeChunk(data: Uint8Array, offset: number): Promise<void> {
+    if (!this.encryptedData) this.encryptedData = new Uint8Array(offset + data.length)
+    this.encryptedData.set(data, offset)
+  }
+
+  async cleanup(): Promise<void> {
+    this.encryptedData = null
+  }
+}
+```
+
+**WorkerMemoryBackend** and **WorkerOPFSBackend** are similar but post messages to a Web Worker instead of calling crypto directly. The Worker then calls the same `encryptFile()`, `decryptChunks()` functions. See §4 for Worker implementation details.
+
+### 3.4 Factory Function
+
+```typescript
+// env.ts
+export function createCryptoBackend(fileSize: number): CryptoBackend {
+  const hasWorker = typeof Worker !== 'undefined'
+  const hasOPFS = typeof navigator?.storage?.getDirectory !== 'undefined'
+  const isLargeFile = fileSize > 50 * 1024 * 1024
+
+  if (hasWorker && hasOPFS && isLargeFile) {
+    return new WorkerOPFSBackend()   // Browser + large file
+  } else if (hasWorker) {
+    return new WorkerMemoryBackend() // Browser + small file
+  } else {
+    return new DirectMemoryBackend() // Node.js
+  }
+}
+```
+
+### 3.5 Usage in agent.ts
+
+```typescript
+// agent.ts - upload orchestration (simplified)
+export async function uploadFile(
+  server: XFTPServer,
+  fileData: Uint8Array,
+  fileName: string,
+  onProgress?: ProgressCallback
+): Promise<string> {
+  // Create backend based on environment
+  const backend = createCryptoBackend(fileData.length)
+
+  try {
+    // Encrypt (runs in Worker in browser, directly in Node)
+    const enc = await backend.encrypt(fileData, fileName, onProgress)
+
+    // Upload chunks (same code regardless of backend)
+    const client = await connectXFTP(server)
+    const sentChunks = []
+    let offset = 0
+    for (const size of enc.chunkSizes) {
+      const chunk = await backend.readChunk(offset, size)
+      const sent = await uploadChunk(client, chunk, enc.digest)
+      sentChunks.push(sent)
+      offset += size
+    }
+
+    // Build description and URI
+    const fd = buildFileDescription(enc, sentChunks)
+    return encodeFileDescriptionURI(fd)
+  } finally {
+    await backend.cleanup()
+  }
+}
+```
+
+The key point: `uploadFile()` logic is identical regardless of whether crypto runs in a Worker or directly. The `CryptoBackend` abstraction hides that detail.
+
+### 3.6 Why This Matters for Testing
+
+- **Layer 1 tests** (per-function): Call `encryptFile()`, `decryptChunks()` directly via Node — unchanged
+- **Layer 2 tests** (full flow): Call `uploadFile()`, `downloadFile()` in Node — uses `DirectMemoryBackend`, same code path as browser except for Worker
+- **Layer 3 tests** (browser): Call `uploadFile()`, `downloadFile()` in Playwright — uses `WorkerMemoryBackend` or `WorkerOPFSBackend`
+
+All three layers exercise the same crypto functions. The only difference is execution context.
+
+## 4. Web Worker Implementation
+
+### 4.1 Why Web Worker
+
+File encryption (XSalsa20-Poly1305) is sequential and CPU-bound:
+- 100 MB file ≈ 1-2 seconds of continuous computation
+- Running on main thread blocks UI (no progress updates, frozen page)
+- Chunking into async microtasks adds complexity and still causes jank
+
+Web Worker runs crypto in parallel thread. Main thread stays responsive.
+
+### 4.2 Architecture
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│  Main Thread                                                 │
+│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────┐  │
+│  │ UI (upload/ │  │ Progress    │  │ Network (fetch)     │  │
+│  │ download)   │  │ display     │  │                     │  │
+│  └──────┬──────┘  └──────▲──────┘  └──────────▲──────────┘  │
+│         │                │                    │              │
+│         │ postMessage    │ progress          │ encrypted    │
+│         ▼                │ events            │ chunks       │
+├─────────────────────────────────────────────────────────────┤
+│  Web Worker                                                  │
+│  ┌─────────────────────────────────────────────────────────┐│
+│  │ Crypto Pipeline                                          ││
+│  │ - encryptFile() with progress callbacks                  ││
+│  │ - decryptChunks() with progress callbacks                ││
+│  │ - OPFS read/write for temp storage                       ││
+│  └─────────────────────────────────────────────────────────┘│
+└─────────────────────────────────────────────────────────────┘
+```
+
+### 4.3 Message Protocol
+
+**Main → Worker:**
+
+```typescript
+type WorkerRequest =
+  // Encrypt file, store result in OPFS (large) or memory (small)
+  | {type: 'encrypt', file: File, fileName: string, useOPFS: boolean}
+  // Read encrypted chunk from OPFS for upload
+  | {type: 'readChunk', offset: number, size: number}
+  // Write downloaded chunk to OPFS for later decryption
+  | {type: 'writeChunk', data: ArrayBuffer, offset: number}
+  // Decrypt from OPFS or provided chunks
+  | {type: 'decrypt', key: Uint8Array, nonce: Uint8Array, size: number, chunks?: ArrayBuffer[]}
+  // Delete OPFS temp files
+  | {type: 'cleanup'}
+  | {type: 'cancel'}
+```
+
+**Worker → Main:**
+
+```typescript
+type WorkerResponse =
+  | {type: 'progress', phase: 'encrypt' | 'decrypt', done: number, total: number}
+  // For OPFS: encData is empty, data lives in OPFS temp file
+  | {type: 'encrypted', encData: ArrayBuffer | null, digest: Uint8Array, key: Uint8Array, nonce: Uint8Array, chunkSizes: number[]}
+  | {type: 'chunk', data: ArrayBuffer}  // Response to readChunk
+  | {type: 'chunkWritten'}              // Response to writeChunk
+  | {type: 'decrypted', header: FileHeader, content: ArrayBuffer}
+  | {type: 'cleaned'}                   // Response to cleanup
+  | {type: 'error', message: string}
+```
+
+### 4.4 Worker Implementation
+
+```typescript
+// crypto.worker.ts
+import {encryptFile, encryptFileStreaming, decryptChunks, decryptFromOPFS} from './crypto/file.js'
+import {sha512} from './crypto/digest.js'
+import {prepareChunkSizes} from './protocol/chunks.js'
+
+let opfsHandle: FileSystemSyncAccessHandle | null = null
+
+self.onmessage = async (e: MessageEvent<WorkerRequest>) => {
+  const req = e.data
+
+  if (req.type === 'encrypt') {
+    const key = crypto.getRandomValues(new Uint8Array(32))
+    const nonce = crypto.getRandomValues(new Uint8Array(24))
+
+    if (req.useOPFS) {
+      // Large file: stream through OPFS to avoid memory pressure
+      const root = await navigator.storage.getDirectory()
+      const fileHandle = await root.getFileHandle('encrypted-temp', {create: true})
+      opfsHandle = await fileHandle.createSyncAccessHandle()
+
+      // Stream encrypt: read 64KB from File, encrypt, write to OPFS
+      const digest = await encryptFileStreaming(
+        req.file,
+        req.fileName,
+        key,
+        nonce,
+        opfsHandle,
+        (done, total) => self.postMessage({type: 'progress', phase: 'encrypt', done, total})
+      )
+
+      const encSize = opfsHandle.getSize()
+      const chunkSizes = prepareChunkSizes(encSize)
+
+      self.postMessage({
+        type: 'encrypted',
+        encData: null,  // Data in OPFS, not memory
+        digest, key, nonce, chunkSizes
+      })
+    } else {
+      // Small file: in-memory is fine
+      const source = new Uint8Array(await req.file.arrayBuffer())
+      const encData = encryptFile(source, req.fileName, key, nonce, (done, total) => {
+        self.postMessage({type: 'progress', phase: 'encrypt', done, total})
+      })
+
+      const digest = sha512(encData)
+      const chunkSizes = prepareChunkSizes(encData.length)
+
+      self.postMessage({
+        type: 'encrypted',
+        encData: encData.buffer,
+        digest, key, nonce, chunkSizes
+      }, [encData.buffer])
+    }
+  }
+
+  if (req.type === 'readChunk') {
+    // Read chunk from OPFS for upload
+    const chunk = new Uint8Array(req.size)
+    opfsHandle!.read(chunk, {at: req.offset})
+    self.postMessage({type: 'chunk', data: chunk.buffer}, [chunk.buffer])
+  }
+
+  if (req.type === 'writeChunk') {
+    // Write downloaded chunk to OPFS
+    if (!opfsHandle) {
+      const root = await navigator.storage.getDirectory()
+      const fileHandle = await root.getFileHandle('download-temp', {create: true})
+      opfsHandle = await fileHandle.createSyncAccessHandle()
+    }
+    opfsHandle.write(new Uint8Array(req.data), {at: req.offset})
+    self.postMessage({type: 'chunkWritten'})
+  }
+
+  if (req.type === 'decrypt') {
+    let result
+    if (req.chunks) {
+      // Small file: chunks provided in memory
+      const chunks = req.chunks.map(b => new Uint8Array(b))
+      result = decryptChunks(chunks, req.key, req.nonce, req.size, (done, total) => {
+        self.postMessage({type: 'progress', phase: 'decrypt', done, total})
+      })
+    } else {
+      // Large file: read from OPFS
+      result = decryptFromOPFS(opfsHandle!, req.key, req.nonce, req.size, (done, total) => {
+        self.postMessage({type: 'progress', phase: 'decrypt', done, total})
+      })
+    }
+
+    self.postMessage({
+      type: 'decrypted',
+      header: result.header,
+      content: result.content.buffer
+    }, [result.content.buffer])
+  }
+
+  if (req.type === 'cleanup') {
+    if (opfsHandle) {
+      opfsHandle.close()
+      opfsHandle = null
+    }
+    const root = await navigator.storage.getDirectory()
+    try { await root.removeEntry('encrypted-temp') } catch {}
+    try { await root.removeEntry('download-temp') } catch {}
+    self.postMessage({type: 'cleaned'})
+  }
+}
+```
+
+### 4.5 Main Thread Wrapper
+
+```typescript
+// crypto-worker.ts (main thread)
+export class CryptoWorker {
+  private worker: Worker
+  private pending: Map<string, {resolve: Function, reject: Function}> = new Map()
+  private onProgress?: (done: number, total: number) => void
+
+  constructor() {
+    this.worker = new Worker(new URL('./crypto.worker.js', import.meta.url), {type: 'module'})
+    this.worker.onmessage = (e) => this.handleMessage(e.data)
+  }
+
+  async encrypt(file: File, onProgress?: (done: number, total: number) => void): Promise<EncryptedFileInfo> {
+    const useOPFS = file.size > 50 * 1024 * 1024  // 50 MB threshold
+    return new Promise((resolve, reject) => {
+      this.pending.set('encrypt', {resolve, reject})
+      this.onProgress = onProgress
+      this.worker.postMessage({type: 'encrypt', file, fileName: file.name, useOPFS})
+    })
+  }
+
+  async decrypt(
+    chunks: Uint8Array[],
+    key: Uint8Array,
+    nonce: Uint8Array,
+    size: number,
+    onProgress?: (done: number, total: number) => void
+  ): Promise<DownloadResult> {
+    return new Promise((resolve, reject) => {
+      this.pending.set('decrypt', {resolve, reject})
+      this.onProgress = onProgress
+      this.worker.postMessage({
+        type: 'decrypt',
+        chunks: chunks.map(c => c.buffer),
+        key, nonce, size
+      }, chunks.map(c => c.buffer))
+    })
+  }
+
+  private handleMessage(msg: WorkerResponse) {
+    if (msg.type === 'progress') {
+      this.onProgress?.(msg.done, msg.total)
+    } else if (msg.type === 'encrypted') {
+      this.pending.get('encrypt')?.resolve({
+        encData: msg.encData ? new Uint8Array(msg.encData) : null,  // null when using OPFS
+        digest: msg.digest,
+        key: msg.key,
+        nonce: msg.nonce,
+        chunkSizes: msg.chunkSizes
+      })
+    } else if (msg.type === 'decrypted') {
+      this.pending.get('decrypt')?.resolve({
+        header: msg.header,
+        content: new Uint8Array(msg.content)
+      })
+    } else if (msg.type === 'error') {
+      // Reject all pending
+      for (const p of this.pending.values()) p.reject(new Error(msg.message))
+    }
+  }
+}
+```
+
+## 5. OPFS Implementation
+
+### 5.1 Purpose
+
+For files approaching 100 MB, holding encrypted data in memory while uploading creates memory pressure. OPFS provides temporary file storage:
+- Write encrypted data to OPFS as it's generated
+- Read chunks from OPFS for upload
+- Delete after upload completes
+
+### 5.2 When to Use
+
+- Files > 50 MB: Use OPFS
+- Files ≤ 50 MB: In-memory (simpler, no OPFS overhead)
+
+Threshold is configurable.
+
+### 5.3 OPFS API
+
+```typescript
+// In Web Worker (synchronous API for performance)
+const root = await navigator.storage.getDirectory()
+const fileHandle = await root.getFileHandle('encrypted-temp', {create: true})
+const accessHandle = await fileHandle.createSyncAccessHandle()
+
+// Write encrypted chunks as they're generated
+accessHandle.write(encryptedChunk, {at: offset})
+
+// Read chunk for upload
+const chunk = new Uint8Array(chunkSize)
+accessHandle.read(chunk, {at: chunkOffset})
+
+// Cleanup
+accessHandle.close()
+await root.removeEntry('encrypted-temp')
+```
+
+### 5.4 Upload Flow with OPFS
+
+```
+1. Main: user drops file
+2. Main → Worker: {type: 'encrypt', file}
+3. Worker:
+   - Create OPFS temp file
+   - Encrypt 64KB at a time, write to OPFS
+   - Post progress every 64KB
+   - Compute digest
+   - Return {digest, key, nonce, chunkSizes} (data stays in OPFS)
+4. Main: for each chunk:
+   - Main → Worker: {type: 'readChunk', offset, size}
+   - Worker: read from OPFS, return chunk
+   - Main: upload chunk via fetch()
+5. Main → Worker: {type: 'cleanup'}
+6. Worker: delete OPFS temp file
+```
+
+### 5.5 Download Flow with OPFS
+
+```
+1. Main: parse URL, get FileDescription
+2. Main: for each chunk:
+   - Download via fetch()
+   - Main → Worker: {type: 'writeChunk', data, offset}
+   - Worker: write to OPFS temp file
+3. Main → Worker: {type: 'decrypt', key, nonce, size}
+4. Worker:
+   - Read from OPFS
+   - Decrypt, verify auth tag
+   - Return {header, content}
+5. Main: trigger browser download
+6. Main → Worker: {type: 'cleanup'}
+```
+
+## 6. Implementation Plan
+
+### 6.1 Phase A: fetch() Transport
+
+**Goal:** Replace `node:http2` with `fetch()` in `client.ts`. All existing Node.js tests pass.
+
+1. Rewrite `connectXFTP()` to use fetch() for handshake
+2. Rewrite `sendXFTPCommand()` to use fetch()
+3. Update `createXFTPChunk`, `uploadXFTPChunk`, `downloadXFTPChunk`, etc.
+4. Remove `node:http2` import
+5. Run existing Haskell integration tests — must pass
+
+**Files:** `client.ts`
+
+### 6.2 Phase B: Environment Abstraction + Web Worker
+
+**Goal:** Add `CryptoBackend` abstraction (§3) so the same code works in Node (direct) and browser (Worker).
+
+1. Create `env.ts` with `CryptoBackend` interface and `createCryptoBackend()` factory (as specified in §3)
+2. Implement `DirectMemoryBackend` for Node.js
+3. Create `crypto.worker.ts` that imports and calls existing crypto functions
+4. Implement `WorkerMemoryBackend` for browser
+5. Update `agent.ts` to use `createCryptoBackend()` instead of direct crypto calls
+6. Existing tests pass (now using `DirectMemoryBackend`)
+
+**Files:** `env.ts`, `crypto.worker.ts`, `agent.ts`
+
+### 6.3 Phase C: OPFS Backend
+
+**Goal:** Large files (>50 MB) use OPFS for temp storage in browser.
+
+1. Implement `WorkerOPFSBackend` — uses OPFS sync API in worker
+2. Add OPFS helpers in worker: read/write to temp file
+3. Factory function now returns `WorkerOPFSBackend` for large files
+4. Same `agent.ts` code works — only backend implementation differs
+
+**Files:** `env.ts`, `crypto.worker.ts`
+
+### 6.4 Phase D: Browser Testing
+
+**Goal:** Verify everything works in real browsers.
+
+1. Create minimal test HTML page
+2. Test upload flow in Chrome, Firefox, Safari
+3. Test download flow
+4. Test progress reporting
+5. Test cancellation
+6. Test error handling (network failure, invalid file)
+
+## 7. Testing Strategy
+
+### 7.1 Test Layers
+
+The `CryptoBackend` abstraction (§3) enables testing at multiple levels without code duplication:
+
+```
+┌─────────────────────────────────────────────────────────────────┐
+│ Layer 3: Browser Integration (Playwright)                        │
+│ - Web Worker message passing                                     │
+│ - OPFS read/write                                                │
+│ - Progress UI updates                                            │
+│ - Real browser fetch() with CORS                                 │
+├─────────────────────────────────────────────────────────────────┤
+│ Layer 2: Full Flow (Haskell-driven, Node.js)                     │
+│ - fetch() transport against real xftp-server                     │
+│ - Upload: encrypt → chunk → upload → build description           │
+│ - Download: parse → download → verify → decrypt                  │
+│ - Cross-language: TS upload ↔ Haskell download (and vice versa)  │
+├─────────────────────────────────────────────────────────────────┤
+│ Layer 1: Per-Function (Haskell-driven, Node.js)                  │
+│ - 172 existing tests                                             │
+│ - Byte-identical output vs Haskell functions                     │
+└─────────────────────────────────────────────────────────────────┘
+```
+
+### 7.2 Layer 1: Per-Function Tests (Existing)
+
+Existing Haskell-driven tests in `XFTPWebTests.hs`. Each test calls a TypeScript function via Node and compares output with Haskell.
+
+```bash
+cabal test --ghc-options -O0 --test-option='--match=/XFTP Web Client/'
+```
+
+All 172 tests must pass. No changes needed for browser transport work.
+
+### 7.3 Layer 2: Full Flow Tests (Node.js + fetch)
+
+Haskell-driven integration tests using Node.js native fetch(). These test the complete upload/download flow without Worker/OPFS.
+
+```haskell
+-- XFTPWebTests.hs (extends existing test file)
+it "fetch transport: upload and download round-trip" $ do
+  withXFTPServer testXFTPServerConfigSNI $ \server -> do
+    -- TypeScript uploads via fetch(), returns URI
+    uri <- jsOut $ callTS "src/agent" "uploadFileTest" serverAddrHex <> testFileHex
+    -- TypeScript downloads via fetch()
+    content <- jsOut $ callTS "src/agent" "downloadFileTest" uriHex
+    content `shouldBe` testFileContent
+
+it "fetch transport: TS upload, Haskell download" $ do
+  withXFTPServer testXFTPServerConfigSNI $ \server -> do
+    uri <- jsOut $ callTS "src/agent" "uploadFileTest" serverAddrHex <> testFileHex
+    -- Haskell agent downloads using existing xftp CLI pattern
+    outPath <- withAgent 1 agentCfg initAgentServers testDB $ \a -> do
+      rfId <- xftpReceiveFile' a 1 uri Nothing
+      waitRfDone a
+    content <- B.readFile outPath
+    content `shouldBe` testFileContent
+```
+
+**What this tests:**
+- fetch() handshake (challenge-response, TLS session binding)
+- fetch() command execution (FNEW, FPUT, FGET, FACK)
+- Streaming request/response bodies
+- Full encrypt → upload → download → decrypt flow
+
+**What this doesn't test:**
+- Web Worker message passing
+- OPFS storage
+- Browser-specific fetch() behavior (CORS preflight, etc.)
+
+### 7.4 Layer 3: Browser Integration Tests (Playwright)
+
+Playwright tests run in real browsers, testing browser-specific functionality.
+
+**Test infrastructure:**
+
+```
+xftp-web/
+├── test/
+│   ├── browser.test.ts      # Playwright test file
+│   └── test-server.ts       # Spawns xftp-server for tests
+└── test-page/
+    ├── index.html           # Minimal test UI
+    └── test-harness.ts      # Exposes test functions to window
+```
+
+**Running browser tests:**
+
+```bash
+cd xftp-web
+npm run test:browser  # Spawns xftp-server, runs Playwright
+```
+
+**Test cases:**
+
+```typescript
+// test/browser.test.ts
+import { test, expect } from '@playwright/test'
+import { spawn } from 'child_process'
+
+let serverProcess: ChildProcess
+
+test.beforeAll(async () => {
+  // Spawn xftp-server with SNI cert for browser TLS
+  serverProcess = spawn('xftp-server', ['start', '-c', 'test-config.ini'])
+  await waitForServer()
+})
+
+test.afterAll(async () => {
+  serverProcess.kill()
+})
+
+test('small file upload/download (in-memory)', async ({ page }) => {
+  await page.goto('/test-page/')
+
+  const result = await page.evaluate(async () => {
+    const data = new Uint8Array(1024 * 1024)  // 1 MB
+    crypto.getRandomValues(data)
+    const file = new File([data], 'small.bin')
+
+    const uri = await window.xftp.uploadFile(file)
+    const downloaded = await window.xftp.downloadFile(uri)
+
+    return {
+      uploadedSize: data.length,
+      downloadedSize: downloaded.length,
+      match: arraysEqual(data, downloaded),
+      usedOPFS: window.xftp.lastUploadUsedOPFS
+    }
+  })
+
+  expect(result.match).toBe(true)
+  expect(result.usedOPFS).toBe(false)  // Small file, no OPFS
+})
+
+test('large file upload/download (OPFS)', async ({ page }) => {
+  await page.goto('/test-page/')
+
+  const result = await page.evaluate(async () => {
+    const data = new Uint8Array(60 * 1024 * 1024)  // 60 MB
+    crypto.getRandomValues(data)
+    const file = new File([data], 'large.bin')
+
+    const uri = await window.xftp.uploadFile(file)
+    const downloaded = await window.xftp.downloadFile(uri)
+
+    return {
+      match: arraysEqual(data, downloaded),
+      usedOPFS: window.xftp.lastUploadUsedOPFS
+    }
+  })
+
+  expect(result.match).toBe(true)
+  expect(result.usedOPFS).toBe(true)  // Large file, used OPFS
+})
+
+test('progress events fire during upload', async ({ page }) => {
+  await page.goto('/test-page/')
+
+  const progressEvents = await page.evaluate(async () => {
+    const events: number[] = []
+    const data = new Uint8Array(10 * 1024 * 1024)  // 10 MB
+    const file = new File([data], 'progress.bin')
+
+    await window.xftp.uploadFile(file, (done, total) => {
+      events.push(done / total)
+    })
+
+    return events
+  })
+
+  expect(progressEvents.length).toBeGreaterThan(1)
+  expect(progressEvents[progressEvents.length - 1]).toBe(1)  // 100% at end
+})
+
+test('Web Worker keeps UI responsive', async ({ page }) => {
+  await page.goto('/test-page/')
+
+  // Start upload and measure main thread responsiveness
+  const result = await page.evaluate(async () => {
+    const data = new Uint8Array(50 * 1024 * 1024)  // 50 MB
+    const file = new File([data], 'responsive.bin')
+
+    let frameCount = 0
+    let uploadDone = false
+
+    // Count animation frames during upload
+    function countFrames() {
+      frameCount++
+      if (!uploadDone) requestAnimationFrame(countFrames)
+    }
+    requestAnimationFrame(countFrames)
+
+    const start = performance.now()
+    await window.xftp.uploadFile(file)
+    uploadDone = true
+    const elapsed = performance.now() - start
+
+    // If main thread was blocked, frameCount would be very low
+    const expectedFrames = (elapsed / 1000) * 30  // ~30 fps minimum
+    return { frameCount, expectedFrames, elapsed }
+  })
+
+  // Should maintain reasonable frame rate (Worker offloaded crypto)
+  expect(result.frameCount).toBeGreaterThan(result.expectedFrames * 0.5)
+})
+```
+
+### 7.5 Cross-Browser Matrix
+
+| Browser | fetch streaming | Web Worker | OPFS sync | Status |
+|---------|----------------|------------|-----------|--------|
+| Chrome 105+ | ✓ | ✓ | ✓ | Primary target |
+| Firefox 111+ | ✓ | ✓ | ✓ | Supported |
+| Safari 16.4+ | ✓ | ✓ | ✓ | Supported |
+| Edge 105+ | ✓ | ✓ | ✓ | Supported (Chromium) |
+
+Playwright tests run against Chrome by default. CI can run against all browsers.
+
+### 7.6 Test Execution Summary
+
+| Phase | Test Layer | Command | What's Verified |
+|-------|-----------|---------|-----------------|
+| A | Layer 1 + 2 | `cabal test --test-option='--match=/XFTP Web Client/'` | fetch() transport, full flow |
+| B | Layer 3 | `npm run test:browser` | Worker message passing, progress |
+| C | Layer 3 | `npm run test:browser` | OPFS storage for large files |
+| D | Layer 3 | `npm run test:browser -- --project=firefox,webkit` | Cross-browser |

rfcs/2026-01-30-send-file-page/2026-02-04-xftp-web-page.md

@@ -0,0 +1,772 @@
+# Send File Web Page — Implementation Plan
+
+## TOC
+1. Executive Summary
+2. Architecture
+3. CryptoBackend & Web Worker
+4. Server Configuration
+5. Page Structure & UI
+6. Upload Flow
+7. Download Flow
+8. Build & Dev Setup
+9. agent.ts Changes
+10. Testing
+11. Files
+12. Implementation Order
+
+## 1. Executive Summary
+
+Build a static web page for browser-based XFTP file transfer (Phase 5 of master RFC). The page supports upload (drag-drop → encrypt → upload → shareable link) and download (open link → download → decrypt → save). Crypto runs in a Web Worker; large files use OPFS temp storage.
+
+Two build variants:
+- **Local**: single test server at `localhost:7000` (development/testing)
+- **Production**: 12 preset XFTP servers (6 SimpleX + 6 Flux)
+
+Uses Vite for bundling (already a dependency via vitest). No CSS framework — plain CSS per RFC spec.
+
+## 2. Architecture
+
+```
+xftp-web/
+├── src/                        # Library (existing, targeted changes)
+│   ├── agent.ts                # Modified: uploadFile readChunk, downloadFileRaw
+│   ├── client.ts               # Modified: downloadXFTPChunkRaw
+│   ├── crypto/                 # Unchanged
+│   ├── download.ts             # Unchanged
+│   └── protocol/
+│       └── description.ts      # Fix: SHA-256 → SHA-512 comment on digest field
+├── web/                        # Web page (new)
+│   ├── index.html              # Entry point (CSP meta tag)
+│   ├── main.ts                 # Router + sodium.ready init
+│   ├── upload.ts               # Upload UI + orchestration
+│   ├── download.ts             # Download UI + orchestration
+│   ├── progress.ts             # Circular progress canvas component
+│   ├── servers.ts              # Server list (build-time configured, imports servers.json)
+│   ├── servers.json            # Preset server addresses (shared with vite.config.ts)
+│   ├── crypto-backend.ts       # CryptoBackend interface + WorkerBackend
+│   ├── crypto.worker.ts        # Web Worker: encrypt/decrypt/OPFS
+│   └── style.css               # Minimal styling
+├── vite.config.ts              # Page build config (new)
+├── tsconfig.web.json           # IDE/CI type-check for web/ (new)
+├── tsconfig.worker.json        # IDE/CI type-check for worker (new)
+├── playwright.config.ts        # Page E2E test config (new)
+├── vitest.config.ts            # Test config (existing)
+├── .gitignore                  # Existing (add dist-web/)
+└── test/                       # Tests (existing + new page test)
+```
+
+Data flow:
+
+```
+                  ┌───────────────────────────────────────────┐
+                  │ Main Thread                                 │
+                  │                                             │
+                  │  Upload:  upload.ts ──► agent.ts ──► fetch()│
+                  │  Download: download.ts ──► agent.ts ──► fetch()
+                  │         │                                   │
+                  │    postMessage                        HTTP/2 │
+                  │         ▼                                   ▼
+                  │ ┌─────────────────┐             ┌──────────┐│
+                  │ │ Web Worker       │             │ XFTP     ││
+                  │ │ crypto.worker.ts │             │ Server   ││
+                  │ │ ┌─────────────┐ │             └──────────┘│
+                  │ │ │ OPFS temp   │ │                         │
+                  │ │ └─────────────┘ │                         │
+                  │ └─────────────────┘                         │
+                  └───────────────────────────────────────────┘
+```
+
+Both upload and download use `agent.ts` for orchestration (connection pooling, parallel chunk transfers, redirect handling). Upload uses a `readChunk` callback for Worker data access. Download uses an `onRawChunk` callback to route raw encrypted chunks to the Worker for decryption (see §7.2). ACK is the caller's responsibility — `downloadFileRaw` returns the resolved `FileDescription` without ACKing, so the caller can verify integrity before acknowledging.
+
+## 3. CryptoBackend & Web Worker
+
+### 3.1 Interface
+
+```typescript
+// crypto-backend.ts
+export interface CryptoBackend {
+  // Upload: encrypt file, store encrypted data in OPFS
+  encrypt(data: Uint8Array, fileName: string,
+          onProgress?: (done: number, total: number) => void
+  ): Promise<EncryptResult>
+
+  // Upload: read encrypted chunk from OPFS (called by agent.ts via readChunk callback)
+  readChunk(offset: number, size: number): Promise<Uint8Array>
+
+  // Download: transit-decrypt raw chunk and store in OPFS
+  decryptAndStoreChunk(
+    dhSecret: Uint8Array, nonce: Uint8Array,
+    body: Uint8Array, digest: Uint8Array, chunkNo: number
+  ): Promise<void>
+
+  // Download: verify digest + file-level decrypt all stored chunks
+  // Only needs size/digest/key/nonce — not the full FileDescription (avoids sending private keys to Worker)
+  verifyAndDecrypt(params: {size: number, digest: Uint8Array, key: Uint8Array, nonce: Uint8Array}
+  ): Promise<{header: FileHeader, content: Uint8Array}>
+
+  cleanup(): Promise<void>
+}
+
+// Structurally identical to EncryptedFileMetadata from agent.ts (§9.1).
+// Kept separate to avoid crypto-backend.ts importing from agent.ts
+// (which would pull in node:http2 via client.ts, breaking Worker bundling).
+// TypeScript structural typing makes them assignment-compatible.
+export interface EncryptResult {
+  digest: Uint8Array
+  key: Uint8Array
+  nonce: Uint8Array
+  chunkSizes: number[]
+}
+```
+
+### 3.2 Factory
+
+```typescript
+export function createCryptoBackend(): CryptoBackend {
+  if (typeof Worker === 'undefined') {
+    throw new Error('Web Workers required — update your browser')
+  }
+  return new WorkerBackend()
+}
+```
+
+The Worker always uses OPFS for temp storage (single code path — no memory/disk branching). OPFS I/O overhead is negligible relative to crypto and network time. Each Worker session creates a unique directory in OPFS root named `session-<Date.now()>-<crypto.randomUUID()>`, containing `upload.bin` and `download.bin` as needed. `cleanup()` deletes the entire session directory. On Worker startup (before processing messages), sweep OPFS root and delete any `session-*` directories whose embedded timestamp (parsed from the name) is older than 1 hour — this handles stale files from crashed tabs. The OPFS API does not expose directory timestamps, so the name-encoded timestamp is the only reliable mechanism. This prevents cross-tab collisions and unbounded OPFS growth.
+
+### 3.3 Worker message protocol
+
+Every request carries a numeric `id`. Responses carry the same `id`. WorkerBackend maintains a `Map<number, {resolve, reject}>` to match responses to pending promises.
+
+Main → Worker (fields marked `†` are Transferable — arrive as `ArrayBuffer` in Worker, must be wrapped with `new Uint8Array(...)` before use):
+- `{id: number, type: 'encrypt', data†: ArrayBuffer, fileName: string}` — encrypt file, store in OPFS
+- `{id: number, type: 'readChunk', offset: number, size: number}` — read encrypted chunk from OPFS
+- `{id: number, type: 'decryptAndStoreChunk', dhSecret: Uint8Array, nonce: Uint8Array, body†: ArrayBuffer, chunkDigest: Uint8Array, chunkNo: number}` — transit-decrypt + store in OPFS. `chunkDigest` is the per-chunk SHA-256 digest (verified by `decryptReceivedChunk`). Distinct from the file-level SHA-512 digest in `verifyAndDecrypt`.
+- `{id: number, type: 'verifyAndDecrypt', size: number, digest: Uint8Array, key: Uint8Array, nonce: Uint8Array}` — verify digest + file-level decrypt all chunks. Only the four fields needed for verification/decryption are sent — not the full `FileDescription`, which contains private replica keys that the Worker doesn't need.
+- `{id: number, type: 'cleanup'}` — delete OPFS temp files
+
+Worker → Main (fields marked `†` are Transferable):
+- `{id: number, type: 'progress', done: number, total: number}` — encryption/decryption progress (fire-and-forget, no promise)
+- `{id: number, type: 'encrypted', digest: Uint8Array, key: Uint8Array, nonce: Uint8Array, chunkSizes: number[]}` — all fields structured-cloned (not transferred)
+- `{id: number, type: 'chunk', data†: ArrayBuffer}` — readChunk response
+- `{id: number, type: 'stored'}` — decryptAndStore acknowledgment
+- `{id: number, type: 'decrypted', header: FileHeader, content†: ArrayBuffer}` — verifyAndDecrypt response
+- `{id: number, type: 'cleaned'}`
+- `{id: number, type: 'error', message: string}` — rejects the pending promise for this `id`
+
+All messages carrying large `ArrayBuffer` payloads use `postMessage(msg, [transferables])` to transfer ownership instead of structured-clone copying. Only `ArrayBuffer` can be transferred — `Uint8Array`, `number[]`, and other types are always structured-cloned. This applies to: `encrypt` request (`data`), `readChunk` response (`data`), `decryptAndStoreChunk` request (`body`), and `verifyAndDecrypt` response (`content`). The `WorkerBackend` implementation must ensure the transferred `ArrayBuffer` covers the full `Uint8Array` — if `byteOffset !== 0` or `byteLength !== buffer.byteLength`, slice first: `data.buffer.slice(data.byteOffset, data.byteOffset + data.byteLength)`. This is required for `decryptAndStore` request bodies: `sendXFTPCommand` returns `body = fullResp.subarray(XFTP_BLOCK_SIZE)`, which has `byteOffset = XFTP_BLOCK_SIZE`. Other payloads are full-buffer views (§6 step 3 creates `new Uint8Array(await file.arrayBuffer())`; Worker responses allocate fresh buffers) but `WorkerBackend` should guard unconditionally.
+
+### 3.4 Worker internals
+
+**Imports:** The Worker imports directly from `libsodium-wrappers-sumo` (for `await sodium.ready`), `src/crypto/file.js` (`encryptFile`, `encodeFileHeader`, `decryptChunks`), `src/crypto/digest.js` (`sha512`), `src/protocol/chunks.js` (`prepareChunkSizes`, `fileSizeLen`, `authTagSize`), `src/protocol/encoding.js` (`concatBytes`), and `src/download.js` (`decryptReceivedChunk`). `download.js` directly imports `src/protocol/client.js` (for `decryptTransportChunk`). These transitively pull in `src/crypto/secretbox.js`, `src/crypto/keys.js`, and `src/crypto/padding.js`. None of these import `src/agent.ts` or `src/client.ts` — those pull in `node:http2` via dynamic import which would break Worker bundling. Vite tree-shakes the transitive deps automatically. Note: `download.js` → `protocol/client.js` → `crypto/keys.js` transitively pulls in `@noble/curves` (~50-80KB). This is unavoidable since `decryptTransportChunk` needs `dh` from `keys.js`. If Worker bundle size becomes a concern, `decryptReceivedChunk` could be refactored out of `download.js` into a separate module that doesn't import `protocol/client.js`.
+
+**ArrayBuffer → Uint8Array conversion:** All Transferable fields arrive in the Worker as `ArrayBuffer`. The Worker's message handler must wrap them before passing to library functions: `new Uint8Array(msg.data)` for encrypt, `new Uint8Array(msg.body)` for decryptAndStore. Non-transferred fields (`dhSecret`, `nonce`, `digest`, `chunkSizes`) arrive as their original types (`Uint8Array` / `number[]`) via structured clone.
+
+The Worker's encrypt handler calls the same functions as `encryptFileForUpload` in agent.ts (key/nonce generation → `encryptFile` → `sha512` → `prepareChunkSizes`). This is not reimplementation — it's calling the same library functions from a different entry point.
+
+**Libsodium init:** Both the Worker and the main thread must `await sodium.ready` before calling any crypto functions that use libsodium. The Worker does this once on startup before processing messages. The main thread needs it before `connectXFTP` (which uses libsodium via `verifyIdentityProof`) and before `downloadXFTPChunkRaw` (which uses libsodium via `generateX25519KeyPair` + `dh`). In practice, `main.ts` calls `await sodium.ready` at page load, before any XFTP calls.
+
+Encrypt (mirrors `encryptFileForUpload` in agent.ts):
+1. Generate key (32B) + nonce (24B) via `crypto.getRandomValues`
+2. `fileHdr = encodeFileHeader({fileName, fileExtra: null})`
+3. `fileSize = BigInt(fileHdr.length + source.length)`
+4. `payloadSize = Number(fileSize) + fileSizeLen + authTagSize`
+5. `chunkSizes = prepareChunkSizes(payloadSize)`
+6. `encSize = BigInt(chunkSizes.reduce((a, b) => a + b, 0))`
+7. `encData = encryptFile(source, fileHdr, key, nonce, fileSize, encSize)`
+8. `digest = sha512(encData)` — note: the `digest` field comment in `FileDescription` in `description.ts` says "SHA-256" but the actual hash is SHA-512 everywhere (`sha512` in agent.ts and download.ts). Fix the comment during implementation.
+9. Open OPFS upload file via `createSyncAccessHandle`, write `encData`, flush, close handle. Null out `encData` reference.
+10. Reopen the same OPFS file with `createSyncAccessHandle` as a persistent read handle (stored on the Worker module scope). This handle is used by all subsequent `readChunk` calls and closed on `cleanup`.
+11. Post back `{digest, key, nonce, chunkSizes}` (no encData transfer — data stays in OPFS)
+
+readChunk:
+- Use the persistent read handle: `handle.read(buf, {at: offset})` → return slice as transferable ArrayBuffer. OPFS allows only one `FileSystemSyncAccessHandle` per file; the persistent handle avoids per-call open/close overhead.
+
+decryptAndStoreChunk (removes transport encryption only — stored data is still file-level encrypted):
+1. `decryptReceivedChunk(dhSecret, nonce, new Uint8Array(body), chunkDigest)` → transit-decrypted chunk data (still file-level encrypted — only the transport layer is removed). Argument order matches signature `(dhSecret, cbNonce, encData, expectedDigest)` from download.ts. `body` arrives as `ArrayBuffer` via Transferable and must be wrapped; `dhSecret`, `nonce`, `chunkDigest` arrive as `Uint8Array` via structured clone.
+2. On first call, open the OPFS download temp file via `createSyncAccessHandle` and store as a persistent write handle. Record `{chunkNo, size: decrypted.length}` in an in-memory `chunkMeta: Map<number, {offset: number, size: number}>` — offset is the running sum of sizes for chunks stored so far (chunks may arrive out of order with `concurrency > 1`, so offset is assigned as `currentFileOffset`, then `currentFileOffset += size`)
+3. Write decrypted chunk to the persistent handle at the recorded offset
+
+verifyAndDecrypt (mirrors size/digest checks in agent.ts `downloadFile`):
+1. Close the persistent download write handle (flush first), then reopen as a read handle. Read each chunk from OPFS into a `Uint8Array[]` array, ordered by `chunkNo`: for each entry in `chunkMeta` sorted by `chunkNo`, `handle.read(buf, {at: offset})` with the recorded offset and size
+2. Concatenate for verification: `combined = concatBytes(...chunks)`
+3. Verify total size: `combined.length === params.size`
+4. Verify SHA-512 digest: `sha512(combined)` matches `params.digest`
+5. Decrypt: `decryptChunks(BigInt(params.size), chunks, params.key, params.nonce)` — `params.size` is the encrypted file size (`fd.size` = `sum(chunkSizes)` = `decryptChunks`' first param `encSize`). Called directly instead of via `processDownloadedFile` (which expects a full `FileDescription`). Pass the original `chunks` array (not `combined`), as `decryptChunks` handles concatenation internally.
+6. Delete OPFS download temp file
+7. Return `{header, content}` via transferable ArrayBuffer
+
+### 3.5 Browser requirements
+
+The page requires a modern browser with Web Worker and OPFS support:
+- Chrome 102+, Firefox 114+, Safari 15.2+ (Workers + OPFS + ES module Workers — Firefox added module Worker support in 114)
+- If Worker or OPFS is unavailable, the page shows an error message rather than falling back silently.
+
+No `DirectBackend` is needed — the page is browser-only, and tests run in vitest browser mode (real Chromium). The existing library tests (`test/browser.test.ts`) test the crypto/upload/download pipeline directly without Workers.
+
+## 4. Server Configuration
+
+### 4.1 Server lists
+
+`web/servers.json` — single source of truth for preset server addresses (imported by both `servers.ts` and `vite.config.ts`):
+
+```json
+{
+  "simplex": [
+    "xftp://da1aH3nOT-9G8lV7bWamhxpDYdJ1xmW7j3JpGaDR5Ug=@xftp1.simplex.im",
+    "xftp://5vog2Imy1ExJB_7zDZrkV1KDWi96jYFyy9CL6fndBVw=@xftp2.simplex.im",
+    "xftp://PYa32DdYNFWi0uZZOprWQoQpIk5qyjRJ3EF7bVpbsn8=@xftp3.simplex.im",
+    "xftp://k_GgQl40UZVV0Y4BX9ZTyMVqX5ZewcLW0waQIl7AYDE=@xftp4.simplex.im",
+    "xftp://-bIo6o8wuVc4wpZkZD3tH-rCeYaeER_0lz1ffQcSJDs=@xftp5.simplex.im",
+    "xftp://6nSvtY9pJn6PXWTAIMNl95E1Kk1vD7FM2TeOA64CFLg=@xftp6.simplex.im"
+  ],
+  "flux": [
+    "xftp://92Sctlc09vHl_nAqF2min88zKyjdYJ9mgxRCJns5K2U=@xftp1.simplexonflux.com",
+    "xftp://YBXy4f5zU1CEhnbbCzVWTNVNsaETcAGmYqGNxHntiE8=@xftp2.simplexonflux.com",
+    "xftp://ARQO74ZSvv2OrulRF3CdgwPz_AMy27r0phtLSq5b664=@xftp3.simplexonflux.com",
+    "xftp://ub2jmAa9U0uQCy90O-fSUNaYCj6sdhl49Jh3VpNXP58=@xftp4.simplexonflux.com",
+    "xftp://Rh19D5e4Eez37DEE9hAlXDB3gZa1BdFYJTPgJWPO9OI=@xftp5.simplexonflux.com",
+    "xftp://0AznwoyfX8Od9T_acp1QeeKtxUi676IBIiQjXVwbdyU=@xftp6.simplexonflux.com"
+  ]
+}
+```
+
+`web/servers.ts`:
+
+```typescript
+import {parseXFTPServer, type XFTPServer} from '../src/protocol/address.js'
+import presets from './servers.json'
+
+declare const __XFTP_SERVERS__: string[]
+
+const serverAddresses: string[] = typeof __XFTP_SERVERS__ !== 'undefined'
+  ? __XFTP_SERVERS__
+  : [...presets.simplex, ...presets.flux]
+
+export function getServers(): XFTPServer[] {
+  return serverAddresses.map(parseXFTPServer)
+}
+
+export function pickRandomServer(servers: XFTPServer[]): XFTPServer {
+  return servers[Math.floor(Math.random() * servers.length)]
+}
+```
+
+### 4.2 Build-time injection
+
+`vite.config.ts` defines `__XFTP_SERVERS__`:
+- `mode === 'local'`: `["xftp://<test-fingerprint>@localhost:7000"]`
+- `mode === 'production'`: not defined → falls through to hardcoded list
+
+### 4.3 Assumption
+
+Production XFTP servers must have `[WEB]` section configured with a CA-signed certificate for browser TLS. Without this, browsers will reject the self-signed XFTP identity cert. The local test server uses `tests/fixtures/` certs which Chromium accepts via `ignoreHTTPSErrors`.
+
+## 5. Page Structure & UI
+
+### 5.1 Routing
+
+`main.ts` checks `window.location.hash` once on page load:
+- Hash present → download mode
+- Hash absent → upload mode
+
+No `hashchange` listener — the shareable link opens in a new tab. Simple page-load routing.
+
+### 5.2 Upload UI states
+
+1. **Landing**: Drag-drop zone centered, file picker button, size limit note
+2. **Uploading**: Circular progress (canvas), percentage, cancel button
+3. **Complete**: Shareable link (input + copy button), "Install SimpleX" CTA
+4. **Error**: Error message + retry button. On server-unreachable, auto-retry with exponential backoff (1s, 2s, 4s, up to 3 attempts) before showing the error state.
+
+### 5.3 Download UI states
+
+1. **Ready**: Approximate file size displayed (encrypted size from `fd.size` or `fd.redirect.size` — see §7 step 2; file name is unavailable — it's inside the encrypted content), download button
+2. **Downloading**: Circular progress, percentage
+3. **Complete**: Browser save dialog triggered automatically
+4. **Error**: Error message (expired, corrupted, unreachable)
+
+### 5.4 Security summary (RFC §7.4)
+
+Both upload-complete and download-ready states display a brief non-technical security summary:
+- Files are encrypted in the browser before upload — the server never sees file contents.
+- The link contains the decryption key in the hash fragment, which the browser never sends to any server.
+- For maximum security, use the SimpleX app.
+
+### 5.5 File expiry
+
+Display on upload-complete state: "Files are typically available for 48 hours." This is an approximation — actual expiry depends on each XFTP server's `[STORE_LOG]` retention configuration. The 48-hour figure matches the current preset server defaults.
+
+### 5.6 Styling
+
+Plain CSS, no framework. White background, centered content, responsive. Circular progress via `<canvas>` (arc drawing, percentage text in center).
+
+File size limit: 100MB. Displayed on upload page.
+
+### 5.7 CSP
+
+`index.html` includes a `<meta>` Content-Security-Policy tag with a build-time placeholder:
+
+```html
+<meta http-equiv="Content-Security-Policy"
+  content="default-src 'self'; worker-src 'self' blob:; style-src 'self' 'unsafe-inline'; connect-src __CSP_CONNECT_SRC__;">
+```
+
+Vite's `transformIndexHtml` hook (in `vite.config.ts`) replaces `__CSP_CONNECT_SRC__` at build time with origins derived from the server list:
+- Local mode: `https://localhost:7000`
+- Production: `https://xftp1.simplex.im:443 https://xftp2.simplex.im:443 ...` (all 12 servers)
+
+## 6. Upload Flow
+
+`web/upload.ts`:
+
+1. User drops/picks file → `File` object
+2. Validate `file.size <= 100 * 1024 * 1024` — show error if exceeded
+3. Read file: `new Uint8Array(await file.arrayBuffer())` — note: after `backend.encrypt()` transfers the buffer to the Worker, `fileData` is detached (zero-length). Peak memory is ~2× file size (main thread holds original until transfer, Worker holds encrypted copy before OPFS write). Acceptable for the 100MB limit; do not raise the limit without considering memory implications.
+4. Create `CryptoBackend` via factory
+5. Create `XFTPClientAgent`
+6. `backend.encrypt(fileData, file.name, onProgress)` → `EncryptResult`
+   - Encryption progress shown on canvas (Worker posts progress messages)
+7. Pick one random server from configured list (V1: all chunks to same server)
+8. Call `uploadFile(agent, server, metadata, {onProgress, readChunk: (off, sz) => backend.readChunk(off, sz)})`:
+   - `metadata` = `{digest, key, nonce, chunkSizes}` from EncryptResult
+   - Network progress shown on canvas
+   - Returns `{rcvDescription, sndDescription, uri}`
+9. Construct full URL: `window.location.origin + window.location.pathname + '#' + uri`
+10. Display link, copy button
+11. Cleanup: `backend.cleanup()`, `closeXFTPAgent(agent)`
+
+**Cancel:** User can abort via cancel button. Sets an `AbortController` signal that:
+- Sends `{type: 'cleanup'}` to Worker
+- Closes the XFTPClientAgent (drops HTTP/2 connections)
+- Resets UI to landing state
+
+## 7. Download Flow
+
+`web/download.ts`:
+
+1. Parse `window.location.hash.slice(1)` → `decodeDescriptionURI(fragment)` → `FileDescription`
+2. Display file size (`fd.size` bytes, formatted human-readable). Note: `fd.size` is the encrypted size (slightly larger than plaintext due to padding + auth tag). The plaintext size is not available until decryption — display it as an approximate file size. If `fd.redirect !== null`, size comes from `fd.redirect.size` (which is the inner encrypted size).
+3. User clicks "Download"
+4. Create `CryptoBackend` and `XFTPClientAgent`
+5. Call `downloadFileRaw(agent, fd, onRawChunk, {onProgress, concurrency: 3})`:
+   - `onRawChunk` forwards each raw chunk to the Worker: `backend.decryptAndStoreChunk(raw.dhSecret, raw.nonce, raw.body, raw.digest, raw.chunkNo)`
+   - `downloadFileRaw` handles redirect resolution internally (see §7.1), parallel downloads, and connection pooling
+   - Returns the resolved `FileDescription` (inner fd for redirect case, original fd otherwise)
+6. `backend.verifyAndDecrypt({size: resolvedFd.size, digest: resolvedFd.digest, key: resolvedFd.key, nonce: resolvedFd.nonce})` → `{header, content}`
+   - Verifies size + SHA-512 digest + file-level decryption inside Worker. Only the four needed fields are sent — private replica keys stay on the main thread.
+7. ACK: `ackFileChunks(agent, resolvedFd)` — best-effort, after verification succeeds
+8. Sanitize `header.fileName` before use: strip path separators (`/`, `\`), replace null/control characters (U+0000-U+001F, U+007F), strip Unicode bidi override characters (U+202A-U+202E, U+2066-U+2069 — prevents `doc.pdf.exe` appearing as `doc.exe.pdf`), limit length to 255 chars. The filename is user-controlled (set by the uploader) and arrives via decrypted content. Then trigger browser save: `new Blob([content])` → `<a download="${sanitizedName}">` click
+9. Cleanup: `backend.cleanup()`, `closeXFTPAgent(agent)`
+
+### 7.1 Redirect handling
+
+Handled inside `downloadFileRaw` in agent.ts — the web page doesn't see it. When `fd.redirect !== null`:
+
+1. Download redirect chunks via `downloadXFTPChunkRaw` (parallel, same as regular chunks)
+2. Transit-decrypt + verify + file-level decrypt on main thread (redirect data is always small — a few KB of YAML, so main thread decryption is fine)
+3. Parse YAML → inner `FileDescription`, validate against `fd.redirect.{size, digest}`
+4. ACK redirect chunks (best-effort)
+5. Continue downloading inner description's chunks, calling `onRawChunk` for each
+
+### 7.2 Architecture note: download refactoring
+
+Both upload and download use `agent.ts` for orchestration. The key difference is where the crypto/network split happens:
+
+- **Upload**: agent.ts reads encrypted chunks from the Worker via `readChunk` callback, sends them over the network.
+- **Download**: agent.ts receives raw encrypted responses from the network via `downloadXFTPChunkRaw` (DH key exchange + network only, no decryption), passes them to the web page via `onRawChunk` callback, which routes them to the Worker for transit decryption.
+
+This split keeps all expensive crypto off the main thread. Transit decryption uses a custom JS Salsa20 implementation (`xorKeystream` in secretbox.ts) that would block the UI for ~50-200ms on a 4MB chunk. File-level decryption (`decryptChunks`) is similarly expensive. Both happen in the Worker.
+
+The cheap operations stay on the main thread: DH key exchange (`generateX25519KeyPair` + `dh` — ~1ms via libsodium WASM), XFTP command encoding/decoding, connection management.
+
+## 8. Build & Dev Setup
+
+### 8.1 vite.config.ts (new, separate from vitest.config.ts)
+
+```typescript
+import {defineConfig, type Plugin} from 'vite'
+import {readFileSync} from 'fs'
+import {createHash} from 'crypto'
+import presets from './web/servers.json'
+
+function parseHost(addr: string): string {
+  const m = addr.match(/@(.+)$/)
+  if (!m) throw new Error('bad server address: ' + addr)
+  const host = m[1].split(',')[0]
+  return host.includes(':') ? host : host + ':443'
+}
+
+function cspPlugin(servers: string[]): Plugin {
+  const origins = servers.map(s => 'https://' + parseHost(s)).join(' ')
+  return {
+    name: 'csp-connect-src',
+    transformIndexHtml: {
+      order: 'pre',
+      handler(html, ctx) {
+        if (ctx.server) {
+          // Dev mode: remove CSP meta tag entirely — Vite HMR needs inline scripts
+          return html.replace(/<meta\s[^>]*?Content-Security-Policy[\s\S]*?>/i, '')
+        }
+        return html.replace('__CSP_CONNECT_SRC__', origins)
+      }
+    }
+  }
+}
+
+export default defineConfig(({mode}) => {
+  const define: Record<string, string> = {}
+  let servers: string[]
+
+  if (mode === 'local') {
+    const pem = readFileSync('../tests/fixtures/ca.crt', 'utf-8')
+    const der = Buffer.from(pem.replace(/-----[^-]+-----/g, '').replace(/\s/g, ''), 'base64')
+    const fp = createHash('sha256').update(der).digest('base64')
+      .replace(/\+/g, '-').replace(/\//g, '_')
+    servers = [`xftp://${fp}@localhost:7000`]
+    define['__XFTP_SERVERS__'] = JSON.stringify(servers)
+  } else {
+    servers = [...presets.simplex, ...presets.flux]
+  }
+
+  return {
+    root: 'web',
+    build: {outDir: '../dist-web'},
+    define,
+    worker: {format: 'es'},
+    plugins: [cspPlugin(servers)],
+  }
+})
+```
+
+### 8.2 package.json scripts
+
+```json
+"dev": "vite --mode local",
+"build:local": "vite build --mode local",
+"build:prod": "vite build --mode production",
+"preview": "vite preview",
+"check:web": "tsc -p tsconfig.web.json --noEmit && tsc -p tsconfig.worker.json --noEmit"
+```
+
+Note: `check:web` type-checks `src/` twice (once per config) — acceptable for this small library.
+
+Add `vite` as an explicit devDependency (`^6.0.0` — matching the version vitest 3.x depends on transitively). Relying on transitive resolution is fragile across package managers.
+
+### 8.3 TypeScript configuration
+
+The existing `tsconfig.json` has `rootDir: "src"` and `include: ["src/**/*.ts"]` — this is for library compilation only (output to `dist/`). Vite handles `web/` TypeScript compilation independently via esbuild, so the main tsconfig is unchanged. `web/*.ts` files import from `../src/*.js` using relative paths.
+
+Add two tsconfigs for `web/` type-checking — split by environment to avoid type pollution between DOM and WebWorker globals:
+
+`tsconfig.web.json` — main-thread files (DOM globals: `document`, `window`, etc.):
+
+```json
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "rootDir": ".",
+    "noEmit": true,
+    "types": [],
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "DOM"]
+  },
+  "include": ["web/**/*.ts", "src/**/*.ts"],
+  "exclude": ["web/crypto.worker.ts"]
+}
+```
+
+`tsconfig.worker.json` — Worker file (`self`, `FileSystemSyncAccessHandle`, etc.):
+
+```json
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "rootDir": ".",
+    "noEmit": true,
+    "types": [],
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "WebWorker"]
+  },
+  "include": ["web/crypto.worker.ts", "src/**/*.ts"]
+}
+```
+
+Both configs set `"types": []` to prevent auto-inclusion of `@types/node` and `"moduleResolution": "bundler"` for Vite-compatible resolution (JSON imports, `.js` extension mapping). The base config's `"moduleResolution": "node"` would cause false type errors on `import ... from './servers.json'`. Both override `@types/node`, which would pollute DOM/WebWorker environments with Node.js globals (`process`, `Buffer`, etc.). This means `src/client.ts`'s dynamic `import("node:http2")` will produce a type error in these configs. This is acceptable — `src/client.ts` provides `createNodeTransport` which is never used in browser code (Vite tree-shakes it out), and full `src/` type-checking is handled by the base `tsconfig.json`. If the error is distracting, add `src/client.ts` to both configs' `exclude` arrays.
+
+Both extend the library tsconfig (inheriting `strict`, `module`, etc.) and include `src/**/*.ts` so imports from `../src/*.js` resolve. `"noEmit": true` means they're only used for type-checking — Vite handles actual compilation. The inherited `"exclude": ["node_modules", "dist", "test"]` intentionally excludes `test/` — test files are type-checked by their own vitest/playwright configs, not by `check:web`.
+
+### 8.4 Dev workflow
+
+`npm run dev` → Vite dev server at `localhost:5173`, configured for local test server. Start `xftp-server` on port 7000 separately (or via the existing globalSetup).
+
+Note: The CSP meta tag's `default-src 'self'` blocks Vite's injected HMR inline scripts in dev mode. The `cspPlugin` handles this by removing the entire CSP `<meta>` tag in serve mode (dev server), so HMR works without restrictions. Production builds always have the correct CSP.
+
+## 9. Library Changes (agent.ts + client.ts)
+
+Changes to support the web page: upload `readChunk` callback, download `onRawChunk` callback with parallel chunk downloads.
+
+### 9.1 Type changes
+
+Split the existing `EncryptedFileInfo` (which currently has `encData`, `digest`, `key`, `nonce`, `chunkSizes` as direct fields) into a metadata-only base and an extension:
+
+```typescript
+// Metadata-only variant (no encData — data lives in Worker/OPFS)
+export interface EncryptedFileMetadata {
+  digest: Uint8Array
+  key: Uint8Array
+  nonce: Uint8Array
+  chunkSizes: number[]
+}
+
+// Full variant (existing, extends metadata with data)
+export interface EncryptedFileInfo extends EncryptedFileMetadata {
+  encData: Uint8Array
+}
+```
+
+### 9.2 uploadFile signature change
+
+Replace positional optional params with an options bag. Add optional `readChunk`. When provided, `encrypted.encData` is not accessed.
+
+```typescript
+export interface UploadOptions {
+  onProgress?: (uploaded: number, total: number) => void
+  redirectThreshold?: number
+  readChunk?: (offset: number, size: number) => Promise<Uint8Array>
+}
+
+export async function uploadFile(
+  agent: XFTPClientAgent,
+  server: XFTPServer,
+  encrypted: EncryptedFileMetadata,
+  options?: UploadOptions
+): Promise<UploadResult>
+```
+
+Inside `uploadFile`:
+- Chunk read: if `options?.readChunk` is provided, use it. Otherwise, verify `'encData' in encrypted` at runtime (throws `"uploadFile: readChunk required when encData is absent"` if missing), then use `(off, sz) => Promise.resolve((encrypted as EncryptedFileInfo).encData.subarray(off, off + sz))`. This guards against calling `uploadFile` with `EncryptedFileMetadata` but no `readChunk`. For each chunk, call `readChunk(offset, size)` once and use the returned `Uint8Array` for both `getChunkDigest(chunkData)` and `uploadXFTPChunk(..., chunkData)` — do not call `readChunk` twice per chunk.
+- Progress total: `const total = encrypted.chunkSizes.reduce((a, b) => a + b, 0)` — replaces `encrypted.encData.length` (line 129) since `EncryptedFileMetadata` has no `encData`. The values are identical: `encData.length === sum(chunkSizes)`.
+- `buildDescription` parameter type: change from `EncryptedFileInfo` to `EncryptedFileMetadata` — it only accesses `chunkSizes`, `digest`, `key`, `nonce` (not `encData`).
+
+`uploadRedirectDescription` (internal) is unchanged — redirect descriptions are always small and created in-memory by `encryptFileForUpload`.
+
+### 9.3 Backward compatibility
+
+The signature change from positional params `(agent, server, encrypted, onProgress?, redirectThreshold?)` to `(agent, server, encrypted, options?)` is a breaking change for callers that pass `onProgress` or `redirectThreshold`. In practice, the only callers are the browser test (which passes no options — no change needed) and the web page (new code). `EncryptedFileInfo` extends `EncryptedFileMetadata`, so existing callers that pass `EncryptedFileInfo` work without change.
+
+### 9.4 client.ts: downloadXFTPChunkRaw
+
+Split `downloadXFTPChunk` at the network/crypto boundary. The new function does DH key exchange and network I/O but skips transit decryption:
+
+```typescript
+export interface RawChunkResponse {
+  dhSecret: Uint8Array
+  nonce: Uint8Array
+  body: Uint8Array
+}
+
+export async function downloadXFTPChunkRaw(
+  c: XFTPClient, rpKey: Uint8Array, fId: Uint8Array
+): Promise<RawChunkResponse> {
+  const {publicKey, privateKey} = generateX25519KeyPair()
+  const cmd = encodeFGET(encodePubKeyX25519(publicKey))
+  const {response, body} = await sendXFTPCommand(c, rpKey, fId, cmd)
+  if (response.type !== "FRFile") throw new Error("unexpected response: " + response.type)
+  const dhSecret = dh(response.rcvDhKey, privateKey)
+  return {dhSecret, nonce: response.nonce, body}
+}
+```
+
+`RawChunkResponse` contains only what client.ts produces (DH secret, nonce, encrypted body). The chunk metadata (`chunkNo`, `digest`) is added by agent.ts when constructing `RawDownloadedChunk` (see §9.5).
+
+The existing `downloadXFTPChunk` is refactored to call `downloadXFTPChunkRaw` + `decryptReceivedChunk`:
+
+```typescript
+export async function downloadXFTPChunk(
+  c: XFTPClient, rpKey: Uint8Array, fId: Uint8Array, digest?: Uint8Array
+): Promise<Uint8Array> {
+  const {dhSecret, nonce, body} = await downloadXFTPChunkRaw(c, rpKey, fId)
+  return decryptReceivedChunk(dhSecret, nonce, body, digest ?? null)
+}
+```
+
+### 9.5 agent.ts: downloadFileRaw, ackFileChunks, RawDownloadedChunk
+
+New type combining client.ts's `RawChunkResponse` with chunk metadata from agent.ts:
+
+```typescript
+export interface RawDownloadedChunk {
+  chunkNo: number
+  dhSecret: Uint8Array
+  nonce: Uint8Array
+  body: Uint8Array
+  digest: Uint8Array
+}
+```
+
+New function providing download orchestration with a raw chunk callback. Handles connection pooling, parallel downloads, redirect resolution, and progress. Does **not** ACK — the caller ACKs after verification.
+
+```typescript
+export interface DownloadRawOptions {
+  onProgress?: (downloaded: number, total: number) => void
+  concurrency?: number  // max parallel chunk downloads, default 1
+}
+
+export async function downloadFileRaw(
+  agent: XFTPClientAgent,
+  fd: FileDescription,
+  onRawChunk: (chunk: RawDownloadedChunk) => Promise<void>,
+  options?: DownloadRawOptions
+): Promise<FileDescription>
+```
+
+Returns the resolved `FileDescription` — for redirect files this is the inner fd, for non-redirect files this is the original fd. The caller uses this for verification and ACK.
+
+Internal structure:
+
+1. Validate `fd` via `validateFileDescription` (may double-validate if caller already validated via `decodeDescriptionURI` — harmless)
+2. If `fd.redirect !== null`: resolve redirect on main thread (redirect data is small):
+   a. Download redirect chunks via `downloadXFTPChunk` (not raw — main thread decryption is fine for a few KB)
+   b. Verify size + digest, `processDownloadedFile` → YAML bytes
+   c. Parse inner `FileDescription`, validate against `fd.redirect.{size, digest}`
+   d. ACK redirect chunks (best-effort — redirect chunks are small and separate from the file chunks)
+   e. Replace `fd` with inner description
+3. Pre-connect: call `getXFTPServerClient(agent, server)` for each unique server before launching concurrent workers. This ensures the client connection exists in the agent's map, avoiding a race condition where multiple concurrent workers all see the client as missing and each call `connectXFTP` independently (leaking all but the last connection). Known limitation: if a connection drops mid-download and multiple workers attempt reconnection simultaneously, the same TOCTOU race reappears. This is a pre-existing issue in `getXFTPServerClient`; a proper fix (per-key connection promise) is out of scope for this plan but should be tracked for follow-up.
+4. Download file chunks in parallel (concurrency-limited via sliding window):
+   - Create a queue of chunk indices `[0, 1, ..., N-1]`. Launch `min(concurrency, N)` async workers, each pulling the next index from the queue until empty. Each worker loops: pull index → derive key → `getXFTPServerClient` → `downloadXFTPChunkRaw` → `await onRawChunk(...)` → update progress → next index. `await Promise.all(workers)` to wait for completion.
+   - For each chunk: derive key (`decodePrivKeyEd25519` → `ed25519KeyPairFromSeed`), get client (`getXFTPServerClient`), call `downloadXFTPChunkRaw`, `await onRawChunk(...)` with result + `chunkNo` + `chunk.digest`
+   - Each concurrency slot awaits its `onRawChunk` before starting the next download on that slot. With `concurrency > 1`, multiple `onRawChunk` calls may be in-flight concurrently (one per slot). The Worker handles this correctly — messages are queued and processed sequentially.
+   - Update progress after each chunk: `downloaded += chunk.chunkSize; onProgress?.(downloaded, resolvedFd.size)` — both values use encrypted sizes for consistency
+5. Return the resolved `fd`
+
+New helper for ACKing after verification:
+
+```typescript
+export async function ackFileChunks(
+  agent: XFTPClientAgent, fd: FileDescription
+): Promise<void> {
+  for (const chunk of fd.chunks) {
+    const replica = chunk.replicas[0]
+    if (!replica) continue
+    try {
+      const client = await getXFTPServerClient(agent, parseXFTPServer(replica.server))
+      const seed = decodePrivKeyEd25519(replica.replicaKey)
+      const kp = ed25519KeyPairFromSeed(seed)
+      await ackXFTPChunk(client, kp.privateKey, replica.replicaId)
+    } catch (_) {}
+  }
+}
+```
+
+The existing `downloadFile` is refactored to use `downloadFileRaw` internally:
+
+```typescript
+export async function downloadFile(
+  agent: XFTPClientAgent,
+  fd: FileDescription,
+  onProgress?: (downloaded: number, total: number) => void
+): Promise<DownloadResult> {
+  const chunks: Uint8Array[] = []
+  const resolvedFd = await downloadFileRaw(agent, fd, async (raw) => {
+    chunks[raw.chunkNo - 1] = decryptReceivedChunk(
+      raw.dhSecret, raw.nonce, raw.body, raw.digest
+    )
+  }, {onProgress})
+  // verify + file-level decrypt using resolvedFd (inner fd for redirect case)
+  const combined = chunks.length === 1 ? chunks[0] : concatBytes(...chunks)
+  if (combined.length !== resolvedFd.size) throw new Error("downloadFile: file size mismatch")
+  const digest = sha512(combined)
+  if (!digestEqual(digest, resolvedFd.digest)) throw new Error("downloadFile: file digest mismatch")
+  // processDownloadedFile re-concatenates chunks internally — this mirrors the
+  // existing downloadFile pattern (verify on concatenated data, then pass chunks
+  // array to decryptChunks which concatenates again). Acceptable overhead for
+  // correctness: verification must happen on transit-decrypted data before
+  // file-level decryption transforms it.
+  const result = processDownloadedFile(resolvedFd, chunks)
+  await ackFileChunks(agent, resolvedFd)
+  return result
+}
+```
+
+Existing callers retain serial behavior (`concurrency` defaults to 1). The web page opts into parallelism by passing `concurrency: 3`. The browser test (`test/browser.test.ts`) continues to work unchanged. The chunks array is initialized empty (`[]`) and populated by sparse index assignment (`chunks[raw.chunkNo - 1] = ...`), so it correctly handles both redirect and non-redirect cases regardless of the outer fd's chunk count. `digestEqual` is an existing module-private helper in agent.ts (line 327) that performs constant-time byte comparison.
+
+### 9.6 Backward compatibility (download)
+
+`downloadFile` signature is unchanged — existing callers are unaffected. The refactoring adds `downloadFileRaw`, `ackFileChunks`, and `RawDownloadedChunk` as new exports from agent.ts, and `downloadXFTPChunkRaw` + `RawChunkResponse` as new exports from client.ts.
+
+## 10. Testing
+
+### 10.1 Existing tests (unchanged)
+
+- `npm run test:browser` — vitest browser round-trip (library-level)
+- `cabal test --test-option='--match=/XFTP Web Client/'` — Haskell per-function tests
+
+### 10.2 New: page E2E test
+
+Add `test/page.spec.ts` using `@playwright/test` (not vitest browser mode — vitest tests run IN the browser and can't control page navigation; Playwright tests run in Node.js and control the browser). Add `@playwright/test` as a devDependency.
+
+Add `playwright.config.ts` at the project root (`xftp-web/`):
+- `webServer: { command: 'vite build --mode local && vite preview', url: 'http://localhost:4173', reuseExistingServer: !process.env.CI }` — the `url` property tells Playwright to wait until the preview server is ready before running tests
+- `use.ignoreHTTPSErrors: true` (test server uses self-signed cert)
+- `use.launchOptions: { args: ['--ignore-certificate-errors'] }` — required because Playwright's `ignoreHTTPSErrors` only affects page navigation, not `fetch()` calls from in-page JavaScript. Without this flag, the page's `createBrowserTransport` fetch to `https://localhost:7000` would fail TLS validation.
+- `globalSetup`: `'./test/globalSetup.ts'` (starts xftp-server, shared with vitest)
+
+```typescript
+import {test, expect} from '@playwright/test'
+
+test('page upload + download round-trip', async ({page}) => {
+  await page.goto(PAGE_URL)
+  // Set file input via page.setInputFiles()
+  // Wait for upload link to appear: page.waitForSelector('[data-testid="share-link"]')
+  // Extract hash from link text
+  // Navigate to PAGE_URL + '#' + hash
+  // Wait for download complete state
+  // Verify file was offered for save (check download event)
+})
+```
+
+Add script: `"test:page": "playwright test test/page.spec.ts"`
+
+This tests the real bundle including Worker loading, OPFS, and CSP. The existing `test/browser.test.ts` continues to test the library-level pipeline (vitest browser mode, no Workers).
+
+### 10.3 Manual testing
+
+`npm run dev` → open `localhost:5173` in browser → drag file → get link → open link in new tab → download. Requires xftp-server running on port 7000 (local mode).
+
+## 11. Files
+
+**Create:**
+- `xftp-web/web/index.html` — page entry point (includes CSP meta tag)
+- `xftp-web/web/main.ts` — router + libsodium init
+- `xftp-web/web/upload.ts` — upload UI + orchestration
+- `xftp-web/web/download.ts` — download UI + orchestration
+- `xftp-web/web/progress.ts` — circular progress canvas component
+- `xftp-web/web/servers.json` — preset server addresses (shared by servers.ts and vite.config.ts)
+- `xftp-web/web/servers.ts` — server configuration (imports servers.json)
+- `xftp-web/web/crypto-backend.ts` — CryptoBackend interface + WorkerBackend + factory
+- `xftp-web/web/crypto.worker.ts` — Web Worker implementation
+- `xftp-web/web/style.css` — styles
+- `xftp-web/vite.config.ts` — page build config (CSP generation, server list)
+- `xftp-web/tsconfig.web.json` — IDE/CI type-checking for `web/` main-thread files (DOM)
+- `xftp-web/tsconfig.worker.json` — IDE/CI type-checking for `web/crypto.worker.ts` (WebWorker)
+- `xftp-web/playwright.config.ts` — Playwright E2E test config (webServer, globalSetup)
+- `xftp-web/test/page.spec.ts` — page E2E test (Playwright)
+
+**Modify:**
+- `xftp-web/src/agent.ts` — add `EncryptedFileMetadata` type, `uploadFile` options bag with `readChunk`, `downloadFileRaw` with `onRawChunk` callback + parallel downloads, `ackFileChunks`, `RawDownloadedChunk` type, refactor `downloadFile` on top of `downloadFileRaw`, add `import {decryptReceivedChunk} from "./download.js"` (needed by refactored `downloadFile`)
+- `xftp-web/src/client.ts` — add `downloadXFTPChunkRaw`, `RawChunkResponse` type, refactor `downloadXFTPChunk` to use raw variant
+- `xftp-web/package.json` — add dev/build/check:web/test:page scripts, add `vite` + `@playwright/test` devDeps
+- `xftp-web/src/protocol/description.ts` — fix stale "SHA-256" comment on `FileDescription.digest` to "SHA-512"
+- `xftp-web/.gitignore` — add `dist-web/`
+
+## 12. Implementation Order
+
+1. **Library refactoring** — `client.ts`: add `downloadXFTPChunkRaw`; `agent.ts`: add `downloadFileRaw` + parallel downloads, `uploadFile` options bag with `readChunk`; refactor existing `downloadFile` on top of `downloadFileRaw`. Run existing tests to verify no regressions.
+2. **Vite config + HTML shell** — `vite.config.ts`, `index.html`, `main.ts`, verify dev server works
+3. **Server config** — `servers.ts` with both local and production server lists
+4. **CryptoBackend + Worker** — interface, WorkerBackend, Worker implementation, OPFS logic
+5. **Upload flow** — `upload.ts` with drag-drop, encrypt via Worker, upload via agent, show link
+6. **Download flow** — `download.ts` with URL parsing, download via agent `downloadFileRaw`, Worker decrypt, browser save
+7. **Progress component** — `progress.ts` canvas drawing
+8. **Styling** — `style.css`
+9. **Testing** — page E2E test, manual browser verification
+10. **Build scripts** — `build:local`, `build:prod` in package.json

rfcs/2026-01-30-send-file-page/2026-02-04-xftp-web-persistent-connections.md

@@ -0,0 +1,53 @@
+# XFTPClientAgent Pattern
+
+## TOC
+1. Executive Summary
+2. Changes: client.ts
+3. Changes: agent.ts
+4. Changes: test/browser.test.ts
+5. Verification
+
+## Executive Summary
+
+Add `XFTPClientAgent` — a per-server connection pool matching the Haskell pattern. The agent caches `XFTPClient` instances by server URL. All orchestration functions (`uploadFile`, `downloadFile`, `deleteFile`) take `agent` as first parameter and use `getXFTPServerClient(agent, server)` instead of calling `connectXFTP` directly. Connections stay open on success; the caller creates and closes the agent.
+
+`connectXFTP` and `closeXFTP` stay exported (used by `XFTPWebTests.hs` Haskell tests). The `browserClients` hack, per-function `connections: Map`, and `getOrConnect` are deleted.
+
+## Changes: client.ts
+
+**Add** after types section: `XFTPClientAgent` interface, `newXFTPAgent`, `getXFTPServerClient`, `closeXFTPServerClient`, `closeXFTPAgent`.
+
+**Delete**: `browserClients` Map and all `isNode` browser-cache checks in `connectXFTP` and `closeXFTP`.
+
+**Revert `closeXFTP`** to unconditional `c.transport.close()` (browser transport.close() is already a no-op).
+
+`connectXFTP` stays exported (backward compat) but becomes a raw low-level function — no caching.
+
+## Changes: agent.ts
+
+**Imports**: replace `connectXFTP`/`closeXFTP` with `getXFTPServerClient`/`closeXFTPAgent` etc.
+
+**Re-export** from agent.ts: `newXFTPAgent`, `closeXFTPAgent`, `XFTPClientAgent`.
+
+**`uploadFile`**: add `agent: XFTPClientAgent` as first param. Replace `connectXFTP` → `getXFTPServerClient`. Remove `finally { closeXFTP }`. Pass `agent` to `uploadRedirectDescription`.
+
+**`uploadRedirectDescription`**: change from `(client, server, innerFd)` to `(agent, server, innerFd)`. Get client via `getXFTPServerClient`.
+
+**`downloadFile`**: add `agent` param. Delete local `connections: Map`. Replace `getOrConnect` → `getXFTPServerClient`. Remove finally cleanup. Pass `agent` to `downloadWithRedirect`.
+
+**`downloadWithRedirect`**: add `agent` param. Same replacements. Remove try/catch cleanup. Recursive call passes `agent`.
+
+**`deleteFile`**: add `agent` param. Same pattern.
+
+**Delete**: `getOrConnect` function entirely.
+
+## Changes: test/browser.test.ts
+
+Create agent before operations, pass to upload/download, close in finally.
+
+## Verification
+
+1. `npx vitest --run` — browser round-trip test passes
+2. No remaining `browserClients`, `getOrConnect`, or per-function `connections: Map` locals
+3. `connectXFTP` and `closeXFTP` still exported (XFTPWebTests.hs compat)
+4. All orchestration functions take `agent` as first param

rfcs/2026-01-30-send-file-page/2026-02-05-xftp-web-e2e-tests.md

@@ -0,0 +1,859 @@
+# XFTP Web Page E2E Tests Plan
+
+## Table of Contents
+
+1. [Executive Summary](#1-executive-summary)
+2. [Test Infrastructure](#2-test-infrastructure)
+3. [Test Infrastructure - Page Objects](#3-test-infrastructure---page-objects)
+4. [Upload Flow Tests](#4-upload-flow-tests)
+5. [Download Flow Tests](#5-download-flow-tests)
+6. [Edge Cases](#6-edge-cases)
+7. [Implementation Order](#7-implementation-order)
+8. [Test Utilities](#8-test-utilities)
+
+---
+
+## 1. Executive Summary
+
+This document specifies comprehensive Playwright E2E tests for the XFTP web page. The existing test (`page.spec.ts`) performs a basic upload/download round-trip. This plan extends coverage to:
+
+- **Upload flow**: File selection (picker + drag-drop), validation, progress, cancellation, link sharing, error handling
+- **Download flow**: Invalid link handling, download button, progress, file save, error states
+- **Edge cases**: Boundary file sizes, special characters, network failures, multi-chunk files with redirect, UI information display
+
+**Key constraints**:
+- Tests run against a local XFTP server (started via `globalSetup.ts`)
+- Server port is dynamic (read from `/tmp/xftp-test-server.port`)
+- Browser uses `--ignore-certificate-errors` for self-signed certs
+- OPFS and Web Workers are required (Chromium supports both)
+
+**Test file location**: `/code/simplexmq/xftp-web/test/page.spec.ts`
+
+**Architecture**: Tests use the Page Object Model pattern to encapsulate UI interactions, making tests read as domain-specific scenarios rather than raw Playwright API calls.
+
+---
+
+## 2. Test Infrastructure
+
+### 2.1 Current Setup
+
+```
+xftp-web/
+├── playwright.config.ts      # Playwright config (webServer, globalSetup)
+├── test/
+│   ├── globalSetup.ts        # Starts xftp-server, writes port to PORT_FILE
+│   ├── page.spec.ts          # E2E tests (to be extended)
+│   └── pages/                # Page Objects (new)
+│       ├── UploadPage.ts
+│       └── DownloadPage.ts
+```
+
+### 2.2 Prerequisites
+
+- `globalSetup.ts` starts the XFTP server and writes port to `PORT_FILE`
+- Tests must read the port dynamically: `readFileSync(PORT_FILE, 'utf-8').trim()`
+- Vite builds and serves the page at `http://localhost:4173`
+
+---
+
+## 3. Test Infrastructure - Page Objects
+
+Page Objects encapsulate page-specific selectors and actions, providing a clean API for tests. This follows the standard Page Object Model pattern used in simplex-chat and most professional test suites.
+
+### 3.1 UploadPage
+
+```typescript
+// test/pages/UploadPage.ts
+import {Page, Locator, expect} from '@playwright/test'
+
+export class UploadPage {
+  readonly page: Page
+  readonly dropZone: Locator
+  readonly fileInput: Locator
+  readonly progressStage: Locator
+  readonly progressCanvas: Locator
+  readonly statusText: Locator
+  readonly cancelButton: Locator
+  readonly completeStage: Locator
+  readonly shareLink: Locator
+  readonly copyButton: Locator
+  readonly errorStage: Locator
+  readonly errorMessage: Locator
+  readonly retryButton: Locator
+  readonly expiryNote: Locator
+  readonly securityNote: Locator
+
+  constructor(page: Page) {
+    this.page = page
+    this.dropZone = page.locator('#drop-zone')
+    this.fileInput = page.locator('#file-input')
+    this.progressStage = page.locator('#upload-progress')
+    this.progressCanvas = page.locator('#progress-container canvas')
+    this.statusText = page.locator('#upload-status')
+    this.cancelButton = page.locator('#cancel-btn')
+    this.completeStage = page.locator('#upload-complete')
+    this.shareLink = page.locator('[data-testid="share-link"]')
+    this.copyButton = page.locator('#copy-btn')
+    this.errorStage = page.locator('#upload-error')
+    this.errorMessage = page.locator('#error-msg')
+    this.retryButton = page.locator('#retry-btn')
+    this.expiryNote = page.locator('.expiry')
+    this.securityNote = page.locator('.security-note')
+  }
+
+  async goto() {
+    await this.page.goto('http://localhost:4173')
+  }
+
+  async selectFile(name: string, content: Buffer, mimeType = 'application/octet-stream') {
+    await this.fileInput.setInputFiles({name, mimeType, buffer: content})
+  }
+
+  async selectTextFile(name: string, content: string) {
+    await this.selectFile(name, Buffer.from(content, 'utf-8'), 'text/plain')
+  }
+
+  async selectLargeFile(name: string, sizeBytes: number) {
+    // Create large file in browser to avoid memory issues in test process
+    await this.page.evaluate(({name, size}) => {
+      const input = document.getElementById('file-input') as HTMLInputElement
+      const buffer = new ArrayBuffer(size)
+      new Uint8Array(buffer).fill(0x55)
+      const file = new File([buffer], name, {type: 'application/octet-stream'})
+      const dt = new DataTransfer()
+      dt.items.add(file)
+      input.files = dt.files
+      input.dispatchEvent(new Event('change', {bubbles: true}))
+    }, {name, size: sizeBytes})
+  }
+
+  async dragDropFile(name: string, content: Buffer) {
+    // Drag-drop uses same file input handler internally
+    await this.selectFile(name, content)
+  }
+
+  async waitForEncrypting(timeout = 10_000) {
+    await expect(this.statusText).toContainText('Encrypting', {timeout})
+  }
+
+  async waitForUploading(timeout = 30_000) {
+    await expect(this.statusText).toContainText('Uploading', {timeout})
+  }
+
+  async waitForShareLink(timeout = 60_000): Promise<string> {
+    await expect(this.shareLink).toBeVisible({timeout})
+    return await this.shareLink.inputValue()
+  }
+
+  async clickCopy() {
+    await this.copyButton.click()
+    await expect(this.copyButton).toContainText('Copied!')
+  }
+
+  async clickCancel() {
+    await this.cancelButton.click()
+  }
+
+  async clickRetry() {
+    await this.retryButton.click()
+  }
+
+  async expectError(messagePattern: string | RegExp) {
+    await expect(this.errorStage).toBeVisible()
+    await expect(this.errorMessage).toContainText(messagePattern)
+  }
+
+  async expectDropZoneVisible() {
+    await expect(this.dropZone).toBeVisible()
+  }
+
+  async expectProgressVisible() {
+    await expect(this.progressStage).toBeVisible()
+    await expect(this.progressCanvas).toBeVisible()
+  }
+
+  async expectCompleteWithExpiry() {
+    await expect(this.completeStage).toBeVisible()
+    await expect(this.expiryNote).toContainText('48 hours')
+  }
+
+  async expectSecurityNote() {
+    await expect(this.securityNote).toBeVisible()
+    await expect(this.securityNote).toContainText('encrypted')
+  }
+
+  getHashFromLink(url: string): string {
+    return new URL(url).hash
+  }
+}
+```
+
+### 3.2 DownloadPage
+
+```typescript
+// test/pages/DownloadPage.ts
+import {Page, Locator, expect, Download} from '@playwright/test'
+
+export class DownloadPage {
+  readonly page: Page
+  readonly readyStage: Locator
+  readonly downloadButton: Locator
+  readonly progressStage: Locator
+  readonly progressCanvas: Locator
+  readonly statusText: Locator
+  readonly errorStage: Locator
+  readonly errorMessage: Locator
+  readonly retryButton: Locator
+  readonly securityNote: Locator
+
+  constructor(page: Page) {
+    this.page = page
+    this.readyStage = page.locator('#dl-ready')
+    this.downloadButton = page.locator('#dl-btn')
+    this.progressStage = page.locator('#dl-progress')
+    this.progressCanvas = page.locator('#dl-progress-container canvas')
+    this.statusText = page.locator('#dl-status')
+    this.errorStage = page.locator('#dl-error')
+    this.errorMessage = page.locator('#dl-error-msg')
+    this.retryButton = page.locator('#dl-retry-btn')
+    this.securityNote = page.locator('.security-note')
+  }
+
+  async goto(hash: string) {
+    await this.page.goto(`http://localhost:4173${hash}`)
+  }
+
+  async gotoWithLink(fullUrl: string) {
+    const hash = new URL(fullUrl).hash
+    await this.goto(hash)
+  }
+
+  async expectFileReady() {
+    await expect(this.readyStage).toBeVisible()
+    await expect(this.downloadButton).toBeVisible()
+  }
+
+  async expectFileSizeDisplayed() {
+    await expect(this.readyStage).toContainText(/\d+(?:\.\d+)?\s*(?:KB|MB|B)/)
+  }
+
+  async clickDownload(): Promise<Download> {
+    const downloadPromise = this.page.waitForEvent('download')
+    await this.downloadButton.click()
+    return downloadPromise
+  }
+
+  async waitForDownloading(timeout = 30_000) {
+    await expect(this.statusText).toContainText('Downloading', {timeout})
+  }
+
+  async waitForDecrypting(timeout = 30_000) {
+    await expect(this.statusText).toContainText('Decrypting', {timeout})
+  }
+
+  async expectProgressVisible() {
+    await expect(this.progressStage).toBeVisible()
+    await expect(this.progressCanvas).toBeVisible()
+  }
+
+  async expectInitialError(messagePattern: string | RegExp) {
+    // For malformed links - error shown in card without #dl-error stage
+    await expect(this.page.locator('.card .error')).toBeVisible()
+    await expect(this.page.locator('.card .error')).toContainText(messagePattern)
+  }
+
+  async expectRuntimeError(messagePattern: string | RegExp) {
+    // For runtime download errors - uses #dl-error stage
+    await expect(this.errorStage).toBeVisible()
+    await expect(this.errorMessage).toContainText(messagePattern)
+  }
+
+  async expectSecurityNote() {
+    await expect(this.securityNote).toBeVisible()
+    await expect(this.securityNote).toContainText('encrypted')
+  }
+}
+```
+
+### 3.3 Test Fixtures
+
+```typescript
+// test/fixtures.ts
+import {test as base} from '@playwright/test'
+import {UploadPage} from './pages/UploadPage'
+import {DownloadPage} from './pages/DownloadPage'
+import {readFileSync} from 'fs'
+
+// Extend Playwright test with page objects
+export const test = base.extend<{
+  uploadPage: UploadPage
+  downloadPage: DownloadPage
+}>({
+  uploadPage: async ({page}, use) => {
+    const uploadPage = new UploadPage(page)
+    await uploadPage.goto()
+    await use(uploadPage)
+  },
+  downloadPage: async ({page}, use) => {
+    await use(new DownloadPage(page))
+  },
+})
+
+export {expect} from '@playwright/test'
+
+// Test data helpers
+export function createTestContent(size: number, fill = 0x41): Buffer {
+  return Buffer.alloc(size, fill)
+}
+
+export function createTextContent(text: string): Buffer {
+  return Buffer.from(text, 'utf-8')
+}
+
+export function uniqueFileName(base: string, ext = 'txt'): string {
+  return `${base}-${Date.now()}.${ext}`
+}
+```
+
+---
+
+## 4. Upload Flow Tests
+
+### 4.1 File Selection - File Picker Button
+
+**Test ID**: `upload-file-picker`
+
+```typescript
+test('upload via file picker button', async ({uploadPage}) => {
+  await uploadPage.expectDropZoneVisible()
+
+  await uploadPage.selectTextFile('picker-test.txt', 'test content ' + Date.now())
+  await uploadPage.waitForEncrypting()
+  await uploadPage.waitForUploading()
+
+  const link = await uploadPage.waitForShareLink()
+  expect(link).toMatch(/^http:\/\/localhost:\d+\/#/)
+})
+```
+
+### 4.2 File Selection - Drag and Drop
+
+**Test ID**: `upload-drag-drop`
+
+```typescript
+test('upload via drag and drop', async ({uploadPage}) => {
+  await uploadPage.dragDropFile('dragdrop-test.txt', createTextContent('drag drop test'))
+  await uploadPage.expectProgressVisible()
+
+  const link = await uploadPage.waitForShareLink()
+  expect(link).toContain('#')
+})
+```
+
+### 4.3 File Size Validation - Too Large
+
+**Test ID**: `upload-file-too-large`
+
+```typescript
+test('upload rejects file over 100MB', async ({uploadPage}) => {
+  await uploadPage.selectLargeFile('large.bin', 100 * 1024 * 1024 + 1)
+  await uploadPage.expectError('too large')
+  await uploadPage.expectError('100 MB')
+})
+```
+
+### 4.4 File Size Validation - Empty File
+
+**Test ID**: `upload-file-empty`
+
+```typescript
+test('upload rejects empty file', async ({uploadPage}) => {
+  await uploadPage.selectFile('empty.txt', Buffer.alloc(0))
+  await uploadPage.expectError('empty')
+})
+```
+
+### 4.5 Progress Display
+
+**Test ID**: `upload-progress-display`
+
+```typescript
+test('upload shows progress during encryption and upload', async ({uploadPage}) => {
+  await uploadPage.selectFile('progress-test.bin', createTestContent(500 * 1024))
+
+  await uploadPage.expectProgressVisible()
+  await uploadPage.waitForEncrypting()
+  await uploadPage.waitForUploading()
+  await uploadPage.waitForShareLink()
+})
+```
+
+### 4.6 Cancel Button
+
+**Test ID**: `upload-cancel`
+
+```typescript
+test('cancel button aborts upload and returns to landing', async ({uploadPage}) => {
+  await uploadPage.selectFile('cancel-test.bin', createTestContent(1024 * 1024))
+  await uploadPage.expectProgressVisible()
+
+  await uploadPage.clickCancel()
+
+  await uploadPage.expectDropZoneVisible()
+  await expect(uploadPage.shareLink).toBeHidden()
+})
+```
+
+### 4.7 Share Link Display and Copy
+
+**Test ID**: `upload-share-link-copy`
+
+```typescript
+test('share link copy button works', async ({uploadPage, context}) => {
+  await context.grantPermissions(['clipboard-read', 'clipboard-write'])
+
+  await uploadPage.selectTextFile('copy-test.txt', 'copy test content')
+  const link = await uploadPage.waitForShareLink()
+
+  await uploadPage.clickCopy()
+
+  // Verify clipboard (may fail in headless)
+  try {
+    const clipboardText = await uploadPage.page.evaluate(() => navigator.clipboard.readText())
+    expect(clipboardText).toBe(link)
+  } catch {
+    // Clipboard API may not be available
+  }
+})
+```
+
+### 4.8 Error Handling and Retry
+
+**Test ID**: `upload-error-retry`
+
+```typescript
+test('error state shows retry button', async ({uploadPage}) => {
+  await uploadPage.selectFile('error-test.txt', Buffer.alloc(0))
+  await uploadPage.expectError('empty')
+  await expect(uploadPage.retryButton).toBeVisible()
+})
+```
+
+---
+
+## 5. Download Flow Tests
+
+### 5.1 Invalid Link Handling - Malformed Hash
+
+**Test ID**: `download-invalid-hash-malformed`
+
+```typescript
+test('download shows error for malformed hash', async ({downloadPage}) => {
+  await downloadPage.goto('#not-valid-base64!!!')
+  await downloadPage.expectInitialError(/[Ii]nvalid|corrupted/)
+  await expect(downloadPage.downloadButton).not.toBeVisible()
+})
+```
+
+### 5.2 Invalid Link Handling - Valid Base64 but Invalid Structure
+
+**Test ID**: `download-invalid-hash-structure`
+
+```typescript
+test('download shows error for invalid structure', async ({downloadPage}) => {
+  await downloadPage.goto('#AAAA')
+  await downloadPage.expectInitialError(/[Ii]nvalid|corrupted/)
+})
+```
+
+### 5.3 Download Button Click
+
+**Test ID**: `download-button-click`
+
+```typescript
+test('download button initiates download', async ({uploadPage, downloadPage}) => {
+  // Upload first
+  await uploadPage.selectTextFile('dl-btn-test.txt', 'download test content')
+  const link = await uploadPage.waitForShareLink()
+
+  // Navigate to download
+  await downloadPage.gotoWithLink(link)
+  await downloadPage.expectFileReady()
+
+  // Click download
+  const download = await downloadPage.clickDownload()
+  expect(download.suggestedFilename()).toBe('dl-btn-test.txt')
+})
+```
+
+### 5.4 Progress Display
+
+**Test ID**: `download-progress-display`
+
+```typescript
+test('download shows progress', async ({uploadPage, downloadPage}) => {
+  await uploadPage.selectFile('dl-progress.bin', createTestContent(500 * 1024))
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const downloadPromise = downloadPage.clickDownload()
+
+  await downloadPage.expectProgressVisible()
+  await downloadPage.waitForDownloading()
+
+  await downloadPromise
+})
+```
+
+### 5.5 File Save Verification
+
+**Test ID**: `download-file-save`
+
+```typescript
+test('downloaded file content matches upload', async ({uploadPage, downloadPage}) => {
+  const content = 'verification content ' + Date.now()
+  const fileName = 'verify.txt'
+
+  await uploadPage.selectTextFile(fileName, content)
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).toBe(fileName)
+
+  const path = await download.path()
+  if (path) {
+    const downloadedContent = (await import('fs')).readFileSync(path, 'utf-8')
+    expect(downloadedContent).toBe(content)
+  }
+})
+```
+
+---
+
+## 6. Edge Cases
+
+### 6.1 Very Small Files
+
+**Test ID**: `edge-small-file`
+
+```typescript
+test('upload and download 1-byte file', async ({uploadPage, downloadPage}) => {
+  await uploadPage.selectFile('tiny.bin', Buffer.from([0x42]))
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).toBe('tiny.bin')
+
+  const path = await download.path()
+  if (path) {
+    const content = (await import('fs')).readFileSync(path)
+    expect(content.length).toBe(1)
+    expect(content[0]).toBe(0x42)
+  }
+})
+```
+
+### 6.2 Files Near 100MB Limit
+
+**Test ID**: `edge-near-limit`
+
+```typescript
+test.slow()
+test('upload file at exactly 100MB', async ({uploadPage}) => {
+  await uploadPage.selectLargeFile('exactly-100mb.bin', 100 * 1024 * 1024)
+
+  // Should succeed (not show error)
+  await expect(uploadPage.errorStage).toBeHidden({timeout: 5000})
+  await uploadPage.expectProgressVisible()
+
+  // Wait for completion (may take a while)
+  await uploadPage.waitForShareLink(300_000)
+})
+```
+
+### 6.3 Special Characters in Filename
+
+**Test ID**: `edge-special-chars-filename`
+
+```typescript
+test('upload and download file with unicode filename', async ({uploadPage, downloadPage}) => {
+  const fileName = 'test-\u4e2d\u6587-\u0420\u0443\u0441\u0441\u043a\u0438\u0439.txt'
+
+  await uploadPage.selectTextFile(fileName, 'unicode filename test')
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).toBe(fileName)
+})
+
+test('upload and download file with spaces', async ({uploadPage, downloadPage}) => {
+  const fileName = 'my document (final) v2.txt'
+
+  await uploadPage.selectTextFile(fileName, 'spaces test')
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).toBe(fileName)
+})
+
+test('filename with path separators is sanitized', async ({uploadPage, downloadPage}) => {
+  await uploadPage.selectTextFile('../../../etc/passwd', 'path traversal test')
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).not.toContain('/')
+  expect(download.suggestedFilename()).not.toContain('\\')
+})
+```
+
+### 6.4 Network Errors (Mocked)
+
+**Test ID**: `edge-network-error`
+
+```typescript
+test('upload handles network error gracefully', async ({uploadPage}) => {
+  // Intercept and abort POST requests
+  await uploadPage.page.route('**/localhost:*', route => {
+    if (route.request().method() === 'POST') {
+      route.abort('failed')
+    } else {
+      route.continue()
+    }
+  })
+
+  await uploadPage.selectTextFile('network-error.txt', 'network error test')
+  await uploadPage.expectError(/.+/) // Any error message
+})
+```
+
+### 6.5 Binary File Content Integrity
+
+**Test ID**: `edge-binary-content`
+
+```typescript
+test('binary file with all byte values', async ({uploadPage, downloadPage}) => {
+  // Create buffer with all 256 byte values
+  const buffer = Buffer.alloc(256)
+  for (let i = 0; i < 256; i++) buffer[i] = i
+
+  await uploadPage.selectFile('all-bytes.bin', buffer)
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  const path = await download.path()
+  if (path) {
+    const content = (await import('fs')).readFileSync(path)
+    expect(content.length).toBe(256)
+    for (let i = 0; i < 256; i++) {
+      expect(content[i]).toBe(i)
+    }
+  }
+})
+```
+
+### 6.6 Multiple Concurrent Downloads
+
+**Test ID**: `edge-concurrent-downloads`
+
+```typescript
+test('concurrent downloads from same link', async ({browser}) => {
+  const context = await browser.newContext({ignoreHTTPSErrors: true})
+  const page1 = await context.newPage()
+  const upload = new UploadPage(page1)
+
+  await upload.goto()
+  await upload.selectTextFile('concurrent.txt', 'concurrent download test')
+  const link = await upload.waitForShareLink()
+  const hash = upload.getHashFromLink(link)
+
+  // Open two tabs and download concurrently
+  const page2 = await context.newPage()
+  const page3 = await context.newPage()
+  const dl2 = new DownloadPage(page2)
+  const dl3 = new DownloadPage(page3)
+
+  await dl2.goto(hash)
+  await dl3.goto(hash)
+
+  const [download2, download3] = await Promise.all([
+    dl2.clickDownload(),
+    dl3.clickDownload()
+  ])
+
+  expect(download2.suggestedFilename()).toBe('concurrent.txt')
+  expect(download3.suggestedFilename()).toBe('concurrent.txt')
+
+  await context.close()
+})
+```
+
+### 6.7 Redirect File Handling (Multi-chunk)
+
+**Test ID**: `edge-redirect-file`
+
+```typescript
+test.slow()
+test('upload and download multi-chunk file with redirect', async ({uploadPage, downloadPage}) => {
+  // Use ~5MB file to get multiple chunks
+  await uploadPage.selectLargeFile('multi-chunk.bin', 5 * 1024 * 1024)
+  const link = await uploadPage.waitForShareLink(120_000)
+
+  await downloadPage.gotoWithLink(link)
+  const download = await downloadPage.clickDownload()
+
+  expect(download.suggestedFilename()).toBe('multi-chunk.bin')
+
+  const path = await download.path()
+  if (path) {
+    const stat = (await import('fs')).statSync(path)
+    expect(stat.size).toBe(5 * 1024 * 1024)
+  }
+})
+```
+
+### 6.8 UI Information Display
+
+**Test ID**: `edge-ui-info`
+
+```typescript
+test('upload complete shows expiry and security note', async ({uploadPage}) => {
+  await uploadPage.selectTextFile('ui-test.txt', 'ui test')
+  await uploadPage.waitForShareLink()
+
+  await uploadPage.expectCompleteWithExpiry()
+  await uploadPage.expectSecurityNote()
+})
+
+test('download page shows file size and security note', async ({uploadPage, downloadPage}) => {
+  await uploadPage.selectFile('size-test.bin', createTestContent(1024))
+  const link = await uploadPage.waitForShareLink()
+
+  await downloadPage.gotoWithLink(link)
+  await downloadPage.expectFileSizeDisplayed()
+  await downloadPage.expectSecurityNote()
+})
+```
+
+---
+
+## 7. Implementation Order
+
+### Phase 1: Core Infrastructure (Priority: High)
+1. Create `test/pages/UploadPage.ts` with Page Object
+2. Create `test/pages/DownloadPage.ts` with Page Object
+3. Create `test/fixtures.ts` with extended test function
+4. Refactor existing test to use Page Objects
+
+### Phase 2: Core Happy Path (Priority: High)
+5. `upload-file-picker` - Basic upload via file picker
+6. `download-button-click` - Basic download
+7. `download-file-save` - Content verification
+
+### Phase 3: Validation (Priority: High)
+8. `upload-file-too-large` - Size validation
+9. `upload-file-empty` - Empty file validation
+10. `download-invalid-hash-malformed` - Invalid link handling
+11. `download-invalid-hash-structure` - Invalid structure handling
+
+### Phase 4: Progress and Cancel (Priority: Medium)
+12. `upload-progress-display` - Progress visibility
+13. `upload-cancel` - Cancel functionality
+14. `download-progress-display` - Download progress
+
+### Phase 5: Link Sharing (Priority: Medium)
+15. `upload-share-link-copy` - Copy button functionality
+16. `upload-drag-drop` - Drag-drop upload
+
+### Phase 6: Edge Cases (Priority: Low)
+17. `edge-small-file` - 1-byte file
+18. `edge-special-chars-filename` - Unicode/special characters
+19. `edge-binary-content` - Binary content integrity
+20. `edge-near-limit` - 100MB file (slow test)
+21. `edge-network-error` - Network error handling
+
+### Phase 7: Error Recovery and Advanced (Priority: Low)
+22. `upload-error-retry` - Retry after error
+23. `edge-concurrent-downloads` - Concurrent access
+24. `edge-redirect-file` - Multi-chunk file with redirect (slow)
+25. `edge-ui-info` - Expiry message, security notes
+
+---
+
+## 8. Test Utilities
+
+### 8.1 Shared Test Setup
+
+```typescript
+// test/page.spec.ts
+import {test, expect, createTestContent, createTextContent, uniqueFileName} from './fixtures'
+
+test.describe('Upload Flow', () => {
+  test('upload via file picker', async ({uploadPage}) => {
+    // Tests use uploadPage fixture which navigates automatically
+  })
+})
+
+test.describe('Download Flow', () => {
+  test('download works', async ({uploadPage, downloadPage}) => {
+    // Both pages available via fixtures
+  })
+})
+
+test.describe('Edge Cases', () => {
+  // Edge case tests
+})
+```
+
+### 8.2 File Structure
+
+```
+xftp-web/test/
+├── fixtures.ts           # Playwright fixtures with page objects
+├── pages/
+│   ├── UploadPage.ts     # Upload page object
+│   └── DownloadPage.ts   # Download page object
+├── page.spec.ts          # All E2E tests
+└── globalSetup.ts        # Server startup (existing)
+```
+
+---
+
+## Appendix: Test Matrix
+
+| Test ID | Category | Priority | Estimated Time | Dependencies |
+|---------|----------|----------|----------------|--------------|
+| upload-file-picker | Upload | High | 30s | - |
+| upload-drag-drop | Upload | Medium | 30s | - |
+| upload-file-too-large | Upload | High | 5s | - |
+| upload-file-empty | Upload | High | 5s | - |
+| upload-progress-display | Upload | Medium | 45s | - |
+| upload-cancel | Upload | Medium | 30s | - |
+| upload-share-link-copy | Upload | Medium | 30s | - |
+| upload-error-retry | Upload | Low | 30s | - |
+| download-invalid-hash-malformed | Download | High | 5s | - |
+| download-invalid-hash-structure | Download | High | 5s | - |
+| download-button-click | Download | High | 45s | upload |
+| download-progress-display | Download | Medium | 60s | upload |
+| download-file-save | Download | High | 45s | upload |
+| edge-small-file | Edge | Low | 30s | - |
+| edge-near-limit | Edge | Low | 300s | - |
+| edge-special-chars-filename | Edge | Low | 30s | - |
+| edge-network-error | Edge | Low | 45s | - |
+| edge-binary-content | Edge | Low | 30s | - |
+| edge-concurrent-downloads | Edge | Low | 60s | upload |
+| edge-redirect-file | Edge | Low | 120s | - |
+| edge-ui-info | Edge | Low | 60s | upload |
+
+**Total estimated time**: ~18 minutes (excluding 100MB and 5MB tests)

rfcs/2026-01-30-send-file-page/2026-02-08-xftp-web-hello-header.md

@@ -0,0 +1,221 @@
+# XFTP Web Hello Header — Session Re-handshake for Browser Connection Reuse
+
+## 1. Problem Statement
+
+Browser HTTP/2 connection pooling reuses TLS connections across page navigations (same origin = same connection pool). The XFTP server maintains per-TLS-connection session state in `TMap SessionId Handshake` keyed by `tlsUniq tls`. When a browser navigates from the upload page to the download page (or reloads), the new page sends a fresh ClientHello on the reused HTTP/2 connection. The server is already in `HandshakeAccepted` state for that connection, so it routes the request to `processRequest`, which expects a 16384-byte command block but receives a 34-byte ClientHello → `ERR BLOCK`.
+
+**Root cause**: The server cannot distinguish a ClientHello from a command on an already-handshaked connection because both arrive on the same HTTP/2 connection (same `tlsUniq`), and there is no content-level discriminator (ClientHello is unpadded, but the server never gets to parse it — the size check in `processRequest` rejects it first).
+
+**Browser limitation**: `fetch()` provides zero control over HTTP/2 connection pooling. There is no browser API to force a new connection or detect connection reuse before a request is sent.
+
+## 2. Solution Summary
+
+Add an HTTP header `xftp-web-hello` to web ClientHello requests. When the server sees this header on an already-handshaked connection (`HandshakeAccepted` state), it re-runs `processHello` **reusing the existing session keys** (same X25519 key pair from the original handshake). The client then completes the normal handshake flow (sends ClientHandshake, receives ack) and proceeds with commands.
+
+Key properties:
+- Server reuses existing `serverPrivKey` — no new key material generated on re-handshake, so `thAuth` remains consistent with any in-flight commands on concurrent HTTP/2 streams.
+- Header is only checked when `sniUsed` is true (web/browser connections). Native XFTP clients are unaffected.
+- CORS preflight already allows all headers (`Access-Control-Allow-Headers: *`).
+- Web clients always send this header on ClientHello — it's harmless on first connection (`Nothing` state) and enables re-handshake on reused connections (`HandshakeAccepted` state).
+
+## 3. Detailed Technical Design
+
+### 3.1 Server change: parameterize `processHello` (`src/Simplex/FileTransfer/Server.hs`)
+
+The entire server change is parameterizing the existing `processHello` with `Maybe C.PrivateKeyX25519`. Zero new functions.
+
+#### Current code (lines 165-191):
+
+```haskell
+xftpServerHandshakeV1 chain serverSignKey sessions
+  XFTPTransportRequest {thParams = thParams0@THandleParams {sessionId}, reqBody = HTTP2Body {bodyHead}, sendResponse, sniUsed, addCORS} = do
+    s <- atomically $ TM.lookup sessionId sessions
+    r <- runExceptT $ case s of
+      Nothing -> processHello
+      Just (HandshakeSent pk) -> processClientHandshake pk
+      Just (HandshakeAccepted thParams) -> pure $ Just thParams
+    either sendError pure r
+    where
+      processHello = do
+        challenge_ <-
+          if
+            | B.null bodyHead -> pure Nothing
+            | sniUsed -> do
+                XFTPClientHello {webChallenge} <- liftHS $ smpDecode bodyHead
+                pure webChallenge
+            | otherwise -> throwE HANDSHAKE
+        (k, pk) <- atomically . C.generateKeyPair =<< asks random
+        atomically $ TM.insert sessionId (HandshakeSent pk) sessions
+        -- ...build and send ServerHandshake...
+        pure Nothing
+```
+
+#### After (diff is ~10 lines):
+
+```haskell
+xftpServerHandshakeV1 chain serverSignKey sessions
+  XFTPTransportRequest {thParams = thParams0@THandleParams {sessionId}, request, reqBody = HTTP2Body {bodyHead}, sendResponse, sniUsed, addCORS} = do
+--                                                                      ^^^^^^^ bind request
+    s <- atomically $ TM.lookup sessionId sessions
+    r <- runExceptT $ case s of
+      Nothing -> processHello Nothing
+      Just (HandshakeSent pk) -> processClientHandshake pk
+      Just (HandshakeAccepted thParams)
+        | webHello -> processHello (serverPrivKey <$> thAuth thParams)
+        | otherwise -> pure $ Just thParams
+    either sendError pure r
+    where
+      webHello = sniUsed && any (\(t, _) -> tokenKey t == "xftp-web-hello") (fst $ H.requestHeaders request)
+      processHello pk_ = do
+        challenge_ <-
+          if
+            | B.null bodyHead -> pure Nothing
+            | sniUsed -> do
+                XFTPClientHello {webChallenge} <- liftHS $ smpDecode bodyHead
+                pure webChallenge
+            | otherwise -> throwE HANDSHAKE
+        (k, pk) <- maybe
+          (atomically . C.generateKeyPair =<< asks random)
+          (\pk -> pure (C.publicKey pk, pk))
+          pk_
+        atomically $ TM.insert sessionId (HandshakeSent pk) sessions
+        -- ...rest unchanged...
+        pure Nothing
+```
+
+#### What changes:
+
+1. **Bind `request`** in the `XFTPTransportRequest` pattern (+1 field)
+2. **Add `webHello`** binding in `where` clause (1 line) — checks header only when `sniUsed`
+3. **Add `pk_` parameter** to `processHello` (change signature)
+4. **Replace key generation** with `maybe` that generates fresh keys when `pk_ = Nothing`, or derives public from existing private when `pk_ = Just pk` (3 lines replace 1 line)
+5. **Add guard** in `HandshakeAccepted` branch (2 lines replace 1 line)
+6. **Call site** `Nothing -> processHello Nothing` (+1 word)
+7. **One import** added: `Network.HPACK.Token (tokenKey)`
+
+#### Imports to add:
+
+```haskell
+import Network.HPACK.Token (tokenKey)
+```
+
+`OverloadedStrings` (already enabled in Server.hs) provides the `IsString` instance for `CI ByteString`, so `tokenKey t == "xftp-web-hello"` works without importing `Data.CaseInsensitive`. Verified on Hackage: `requestHeaders :: Request -> HeaderTable`, `tokenKey :: Token -> CI ByteString`.
+
+### 3.2 Re-handshake flow
+
+When `webHello` is true in `HandshakeAccepted` state:
+
+1. `processHello (serverPrivKey <$> thAuth thParams)` is called with `Just pk` (existing private key)
+2. `(k, pk) <- pure (C.publicKey pk, pk)` — reuses same key pair, no generation
+3. `TM.insert sessionId (HandshakeSent pk) sessions` — transitions state back to `HandshakeSent` with same `pk`
+4. Server sends `ServerHandshake` response (same format as initial handshake)
+5. Client sends `ClientHandshake` on next stream → enters `Just (HandshakeSent pk) -> processClientHandshake pk` → normal flow
+6. `processClientHandshake` stores `HandshakeAccepted thParams` with same `serverPrivKey = pk`
+
+### 3.3 Web client change (`xftp-web/src/client.ts`)
+
+Add optional `headers?` parameter to `Transport.post()`, thread it through `fetch()` and `session.request()`, and pass `{"xftp-web-hello": "1"}` in the ClientHello call in `connectXFTP`.
+
+### 3.4 What does NOT change
+
+- **CORS**: Already has `Access-Control-Allow-Headers: *` (Server.hs:106).
+- **Native Haskell client**: Uses `[]` headers. No header = existing behavior.
+- **Protocol wire format**: ClientHello, ServerHandshake, ClientHandshake, commands — all unchanged.
+- **`processRequest`**, **`processClientHandshake`**, **`sendError`**, **`encodeXftp`** — unchanged.
+
+### 3.5 Haskell test (`tests/XFTPServerTests.hs`)
+
+Add `testWebReHandshake` next to the existing `testWebHandshake` (line 504). It reuses the same SNI + HTTP/2 setup pattern, performs a full handshake, then sends a second ClientHello with the `xftp-web-hello` header on the same connection and verifies the server responds with a valid ServerHandshake (same `sessionId`), then completes the second handshake.
+
+```haskell
+-- Register in xftpServerTests (after line 86):
+it "should re-handshake on same connection with xftp-web-hello header" testWebReHandshake
+
+-- Test (after testWebHandshake):
+testWebReHandshake :: Expectation
+testWebReHandshake =
+  withXFTPServerSNI $ \_ -> do
+    Fingerprint fp <- loadFileFingerprint "tests/fixtures/ca.crt"
+    let keyHash = C.KeyHash fp
+        cfg = defaultTransportClientConfig {clientALPN = Just ["h2"], useSNI = True}
+    runTLSTransportClient defaultSupportedParamsHTTPS Nothing cfg Nothing "localhost" xftpTestPort (Just keyHash) $ \(tls :: TLS 'TClient) -> do
+      let h2cfg = HC.defaultHTTP2ClientConfig {HC.bodyHeadSize = 65536}
+      h2 <- either (error . show) pure =<< HC.attachHTTP2Client h2cfg (THDomainName "localhost") xftpTestPort mempty 65536 tls
+      g <- C.newRandom
+      -- First handshake (same as testWebHandshake)
+      challenge1 <- atomically $ C.randomBytes 32 g
+      let helloReq1 = H2.requestBuilder "POST" "/" [] $ byteString (smpEncode (XFTPClientHello {webChallenge = Just challenge1}))
+      resp1 <- either (error . show) pure =<< HC.sendRequest h2 helloReq1 (Just 5000000)
+      shs1 <- either error pure $ smpDecode =<< C.unPad (bodyHead (HC.respBody resp1))
+      let XFTPServerHandshake {sessionId = sid1} = shs1
+      clientHsPadded <- either (error . show) pure $ C.pad (smpEncode (XFTPClientHandshake {xftpVersion = VersionXFTP 1, keyHash})) xftpBlockSize
+      resp1b <- either (error . show) pure =<< HC.sendRequest h2 (H2.requestBuilder "POST" "/" [] $ byteString clientHsPadded) (Just 5000000)
+      B.length (bodyHead (HC.respBody resp1b)) `shouldBe` 0
+      -- Second handshake on same connection with xftp-web-hello header
+      challenge2 <- atomically $ C.randomBytes 32 g
+      let helloReq2 = H2.requestBuilder "POST" "/" [("xftp-web-hello", "1")] $ byteString (smpEncode (XFTPClientHello {webChallenge = Just challenge2}))
+      resp2 <- either (error . show) pure =<< HC.sendRequest h2 helloReq2 (Just 5000000)
+      shs2 <- either error pure $ smpDecode =<< C.unPad (bodyHead (HC.respBody resp2))
+      let XFTPServerHandshake {sessionId = sid2} = shs2
+      sid2 `shouldBe` sid1  -- same TLS connection → same sessionId
+      -- Complete second handshake
+      resp2b <- either (error . show) pure =<< HC.sendRequest h2 (H2.requestBuilder "POST" "/" [] $ byteString clientHsPadded) (Just 5000000)
+      B.length (bodyHead (HC.respBody resp2b)) `shouldBe` 0
+```
+
+The only difference from `testWebHandshake`: the second `helloReq2` passes `[("xftp-web-hello", "1")]` instead of `[]`. The test verifies:
+1. Server responds with `ServerHandshake` (not `ERR BLOCK`)
+2. Same `sessionId` (same TLS connection)
+3. Second `ClientHandshake` completes with empty ACK
+
+## 4. Implementation Plan
+
+### Step 1: Server — parameterize `processHello`
+
+Apply the diff from Section 3.1 to `src/Simplex/FileTransfer/Server.hs`.
+
+### Step 2: Test — add `testWebReHandshake`
+
+Add the test from Section 3.5 to `tests/XFTPServerTests.hs`.
+
+### Step 3: Client — add `xftp-web-hello` header
+
+Add optional `headers?` to `Transport.post()`, pass `{"xftp-web-hello": "1"}` on ClientHello in `connectXFTP`.
+
+### Step 4: Test
+
+Run Haskell tests (`cabal test`) and E2E Playwright tests (`npx playwright test` in `xftp-web/`).
+
+## 5. Race Condition Analysis
+
+### Single-tab navigation (the common case)
+
+1. Upload page completes, all fetch() requests finish
+2. Browser navigates to download page (or reloads)
+3. All upload-page fetches are aborted on page unload
+4. Download page sends ClientHello with `xftp-web-hello` header
+5. Server is in `HandshakeAccepted` → `processHello (Just pk)` → `HandshakeSent pk` (same key)
+6. No concurrent streams → no race
+
+**Safe.**
+
+### Multi-tab (edge case)
+
+Tab A (upload) and Tab B (download) share the same HTTP/2 connection.
+
+1. Tab A has active command streams (e.g., FPUT upload in progress)
+2. Tab B sends ClientHello with header
+3. Server reads `HandshakeAccepted` atomically for both streams
+4. Tab A's stream already has its `thParams` snapshot → proceeds with `processRequest` using old `thParams`
+5. Tab B's stream triggers `processHello (Just pk)` → stores `HandshakeSent pk` (same pk!)
+6. Tab A's in-progress FPUT continues with snapshot `thParams` → completes normally (same `serverPrivKey`)
+7. Tab A's NEXT command reads `HandshakeSent` from TMap → enters `processClientHandshake` → fails (command body ≠ ClientHandshake format) → HANDSHAKE error
+
+**Tab A's in-flight commands succeed. Tab A's subsequent commands fail with HANDSHAKE error.** This is the inherent multi-tab problem — unavoidable with per-connection session state and HTTP/2 connection sharing. The failure is clean (HANDSHAKE error, not silent corruption).
+
+## 6. Security Considerations
+
+- **No new key material**: Re-handshake reuses existing `serverPrivKey`. No opportunity for key confusion or downgrade.
+- **Identity re-verification**: Server re-signs the web challenge with its long-term signing key. Client verifies identity again.
+- **Header cannot escalate privileges**: The header only triggers re-handshake (which the server was already capable of doing on first connection). It does not bypass any authentication.
+- **Timing**: Re-handshake takes the same code path as initial handshake, so timing side-channels are unchanged.

rfcs/2026-01-30-send-file-page/2026-02-11-xftp-web-error-handling.md

@@ -0,0 +1,948 @@
+# XFTP Web Error Handling and Connection Resilience
+
+## 1. Problem Statement
+
+The XFTP web client is fundamentally fragile: any transient error (browser opening a new HTTP/2 connection, network hiccup, server restart) causes an unrecoverable failure with a cryptic error message. There is no retry logic, no fetch timeout, no error categorization, and the upload uses a single server instead of distributing chunks across preset servers. This makes the app frustrating — it works most of the time but fails unpredictably, which is worse than being completely broken.
+
+### Confirmed root cause (from diagnostic logs)
+
+When the browser opens a new HTTP/2 connection mid-operation, the new connection has a different TLS SessionId with no handshake state in the server's `TMap SessionId Handshake`. The server's `Nothing` branch in `xftpServerHandshakeV1` (Server.hs:169) unconditionally calls `processHello`, which tries to decode the command body as `XFTPClientHello`, fails, and sends a raw padded "HANDSHAKE" error string. The client cannot parse this as a proper transmission (first byte 'H' = 72 is read as batch count), producing `"expected batch count 1, got 72"`.
+
+Server log confirming the SessionId change:
+```
+DEBUG dispatch: Accepted+command sessId="ZSo1GGETgIvjbB7CWHbvGPpbMjx_b2IlC1eTI6aKfqc="
+...20 successful commands...
+DEBUG dispatch: Nothing sessId="mJC7Sck9xxW5UsXoPGoUWduuHghSVgf6CnD6ZC6SBhU=" webHello=False
+```
+
+### Why re-handshake is required (cannot be made optional)
+
+1. **SessionId is baked into signed command data.** `encodeAuthTransmission` signs `concat(encode(sessionId), tInner)` with Ed25519. Server's `tDecodeServer` (Protocol.hs:2242) verifies `sessId == sessionId`. New connection = different sessionId = signature mismatch.
+2. **Server generates per-session DH keys.** `processHello` creates fresh X25519 keypair stored in `HandshakeSent`. For SMP browser clients (future), `verifyCmdAuth` (Protocol.hs:1322) requires the matching `serverPrivKey` from `thAuth`.
+3. **This applies to both XFTP and future SMP browser clients** — the session management approach is the same.
+
+### Why multiple preset servers cannot work
+
+Upload (`agent.ts:105-157`) takes a single `server: XFTPServer` parameter and uploads ALL chunks to it. `web/upload.ts:133` calls `pickRandomServer(servers)` which selects ONE random server from all presets. The multi-server preset configuration is pointless — only one server is ever used per upload. The design intent (RFC section 11.6: "upload in parallel to 8 randomly selected servers") is not implemented. This must be fixed in Phase 2 (section 3.7).
+
+## 2. Solution Summary
+
+### Phase 1: Error handling and connection resilience
+
+1. **Server: strict dispatch for allowed protocol combinations** — reject all invalid combinations
+2. **Client: automatic retry with re-handshake** on SESSION/HANDSHAKE errors
+3. **Client: fetch timeout** with configurable duration
+4. **UI: error categorization and retry** — auto-retry temporary, human-readable permanent
+5. **Client: connection state with Promise-based lock and per-server queues** — `ServerConnection` with `client: Promise<XFTPClient>` + `queue: Promise<void>`
+6. **Client: fix cache key** — include keyHash
+
+### Phase 2: Multi-server upload (after Phase 1)
+
+7. **Multi-server upload with server selection and failover** — distribute chunks across servers, retry FNEW on different server if one fails
+
+## 3. Detailed Technical Design
+
+### 3.1 Server: strict dispatch for allowed protocol combinations
+
+**Principle:** Everything not explicitly done by existing Haskell/TS clients is prohibited. It is better to fail on impossible combinations than to be permissive — permissiveness complicates debugging and creates attack vectors via unexpected behaviors.
+
+**Allowed behaviors by client type:**
+
+| Client | SNI | webHello header | Hello body | When |
+|--------|-----|----------------|------------|------|
+| Haskell | No | No | Empty | New connection only |
+| Web | Yes | Yes | Non-empty (XFTPClientHello) | New OR existing connection |
+
+**Minimal surgical change.** The existing dispatch (Server.hs:169-189) already correctly handles `HandshakeSent` and `HandshakeAccepted` — their guards cover all valid and invalid combinations. The ONLY missing case is `Nothing` + web client sending a command on a stale session.
+
+`processHello` (Server.hs:194-217) already internally routes: `B.null bodyHead` → Haskell hello, `sniUsed` → web hello decode, else → HANDSHAKE. For stale web sessions, it currently tries to decode a command body as `XFTPClientHello`, fails, and throws HANDSHAKE. The fix: detect this case BEFORE calling processHello and throw SESSION instead, so the client knows to re-handshake (not that its hello was malformed).
+
+**Change: add one guard to `Nothing` branch, remove debug logging.**
+
+```haskell
+-- Before (1 line):
+Nothing -> processHello Nothing
+
+-- After (3 lines):
+Nothing
+  | sniUsed && not webHello -> throwE SESSION  -- web command on stale session
+  | otherwise -> processHello Nothing          -- normal hello (web or Haskell)
+```
+
+`throwE SESSION` is caught by `either sendError pure r` (line 190). `sendError` pads `smpEncode SESSION` = `"SESSION"` (Transport.hs:298) to `xftpBlockSize`. The client's padded error detection (section 3.2) catches this as a retriable error and triggers re-handshake. SESSION is a valid `XFTPErrorType` constructor (Transport.hs:225) — no new helpers needed.
+
+**All other branches remain unchanged.** `HandshakeSent` guards (`webHello` → processHello, `otherwise` → processClientHandshake with body size check inside) are correct. `HandshakeAccepted` guards (`webHello`, `webHandshake`, `otherwise` → command) are correct.
+
+### 3.2 Client: automatic retry with re-handshake
+
+**Location:** `sendXFTPCommand` in `client.ts`
+
+**Design:** Retry loop inside `sendXFTPCommand`. Maximum 3 attempts. On retriable error, close old client, re-handshake, retry.
+
+**Error classification:**
+
+| Error | Type | Retriable? | Human-readable message |
+|-------|------|-----------|----------------------|
+| Padded "HANDSHAKE" | Temporary | Yes (auto) | "Connection interrupted, reconnecting..." |
+| Padded "SESSION" | Temporary | Yes (auto) | "Session expired, reconnecting..." |
+| `FRErr SESSION` | Temporary | Yes (auto) | "Session expired, reconnecting..." |
+| `FRErr HANDSHAKE` | Temporary | Yes (auto) | "Connection interrupted, reconnecting..." |
+| `fetch()` TypeError | Temporary | Yes (auto) | "Network error, retrying..." |
+| AbortError (timeout) | Temporary | Yes (auto) | "Server timeout, retrying..." |
+| `FRErr AUTH` | Permanent | No | "File is invalid, expired, or has been removed" |
+| `FRErr NO_FILE` | Permanent | No | "File not found — it may have expired" |
+| `FRErr SIZE` | Permanent | No | "File size exceeds server limit" |
+| `FRErr QUOTA` | Permanent | No | "Server storage quota exceeded" |
+| `FRErr BLOCKED` | Permanent | No | "File has been blocked by server" |
+| `FRErr DIGEST` | Permanent | No | "File integrity check failed" |
+| `FRErr INTERNAL` | Permanent | No | "Server internal error" |
+| `CMD *` | Permanent | No | "Protocol error" |
+
+**Retry behavior:**
+- Auto-retry up to 3 times for temporary errors, transparent to user
+- After 3 failures: show human-readable error with diagnosis, offer manual retry button
+- Permanent errors: show human-readable error immediately, NO manual retry button (user can reload page)
+
+**Implementation:**
+
+```typescript
+async function sendXFTPCommand(
+  agent: XFTPClientAgent,
+  server: XFTPServer,
+  privateKey: Uint8Array,
+  entityId: Uint8Array,
+  cmdBytes: Uint8Array,
+  chunkData?: Uint8Array,
+  maxRetries: number = 3
+): Promise<{response: FileResponse, body: Uint8Array}> {
+  let clientP = getXFTPServerClient(agent, server)
+  let client = await clientP
+  for (let attempt = 1; attempt <= maxRetries; attempt++) {
+    try {
+      return await sendXFTPCommandOnce(client, privateKey, entityId, cmdBytes, chunkData)
+    } catch (e) {
+      if (!isRetriable(e)) {
+        // Permanent error (AUTH, NO_FILE, etc.) — connection is fine, don't touch it
+        throw categorizeError(e)
+      }
+      if (attempt === maxRetries) {
+        // Retriable error exhausted — connection is bad, remove stale promise
+        removeStaleConnection(agent, server, clientP)
+        throw categorizeError(e)
+      }
+      clientP = reconnectClient(agent, server)
+      client = await clientP
+    }
+  }
+  throw new Error("unreachable")
+}
+```
+
+**`sendXFTPCommandOnce`** — renamed from current `sendXFTPCommand`. Two changes:
+
+1. **Padded error detection** (before `decodeTransmission`):
+
+```typescript
+// After getting respBlock, before decodeTransmission:
+const raw = blockUnpad(respBlock)
+if (raw.length < 20) {
+  const text = new TextDecoder().decode(raw)
+  if (/^[A-Z_]+$/.test(text)) {
+    throw new XFTPRetriableError(text)  // "HANDSHAKE" or "SESSION"
+  }
+}
+```
+
+2. **FRErr classification** (replaces current unconditional throw):
+
+```typescript
+// After decodeResponse, instead of throw new Error("Server error: " + err.type):
+if (response.type === "FRErr") {
+  const err = response.err
+  if (err.type === "SESSION" || err.type === "HANDSHAKE") {
+    throw new XFTPRetriableError(err.type)
+  }
+  throw new XFTPPermanentError(err.type, humanReadableMessage(err))
+}
+```
+
+### 3.3 Client: fetch timeout
+
+**Location:** `createBrowserTransport` and `createNodeTransport` in `client.ts`
+
+**Design:** `AbortController` with configurable timeout on every `fetch()`.
+
+```typescript
+interface TransportConfig {
+  timeoutMs: number  // default 30000, lower for tests
+}
+
+function createBrowserTransport(baseUrl: string, config: TransportConfig): Transport {
+  return {
+    async post(body: Uint8Array, headers?: Record<string, string>): Promise<Uint8Array> {
+      const controller = new AbortController()
+      const timer = setTimeout(() => controller.abort(), config.timeoutMs)
+      try {
+        const resp = await fetch(effectiveUrl, {
+          method: "POST", headers, body,
+          signal: controller.signal
+        })
+        if (!resp.ok) throw new Error(`Server request failed: ${resp.status}`)
+        return new Uint8Array(await resp.arrayBuffer())
+      } finally {
+        clearTimeout(timer)
+      }
+    },
+    close() {}
+  }
+}
+```
+
+For Node.js transport, use `setTimeout` on the HTTP/2 request stream.
+
+Default: 30s for production, 5s for tests. Threaded through `connectXFTP` → `createTransport`.
+
+### 3.4 UI: error categorization and retry
+
+**Behavior (Option D):**
+
+- **Temporary errors:** Auto-retry loop (3 attempts). After 3 failures, show human-readable diagnosis with manual retry button. Diagnosis examples: "Server timeout — the server may be temporarily unavailable", "Connection interrupted — your network may be unstable".
+- **Permanent errors:** Show human-readable error immediately, NO retry button. User can reload page if they want to retry. Examples: "File is invalid, expired, or has been removed" (AUTH), "File not found" (NO_FILE).
+
+**Current UI retry buttons:**
+- `upload.ts:73-75` — retry calls `startUpload(pendingFile)` from scratch
+- `download.ts:60` — retry calls `startDownload()` from scratch
+
+**Improvement:** Track uploaded/downloaded chunk indices. On manual retry, skip completed chunks:
+
+```typescript
+// Upload: track which chunks completed
+const completedChunks: Set<number> = new Set()
+for (let i = 0; i < specs.length; i++) {
+  if (completedChunks.has(i)) continue
+  // ... create + upload chunk
+  completedChunks.add(i)
+}
+
+// Download: already naturally resumable — each chunk is independent
+```
+
+### 3.5 Client: connection state with Promise-based lock and per-server queues
+
+**Design:** Each server gets a `ServerConnection` record containing a `Promise<XFTPClient>` (the connection lock) and a `Promise<void>` (the sequential command queue). The `XFTPClientAgent` maps server keys to these records.
+
+The promise IS the lock — every consumer awaits the same promise. When reconnect is needed, the promise is replaced atomically.
+
+```typescript
+interface ServerConnection {
+  client: Promise<XFTPClient>   // resolves to connected client; replaced on reconnect
+  queue: Promise<void>          // tail of sequential command chain
+}
+
+interface XFTPClientAgent {
+  connections: Map<string, ServerConnection>
+}
+
+function newXFTPAgent(): XFTPClientAgent {
+  return {connections: new Map()}
+}
+```
+
+**Connection lifecycle — `getXFTPServerClient` and `reconnectClient`:**
+
+```typescript
+function getXFTPServerClient(agent: XFTPClientAgent, server: XFTPServer): Promise<XFTPClient> {
+  const key = formatXFTPServer(server)
+  let conn = agent.connections.get(key)
+  if (!conn) {
+    const p = connectXFTP(server)
+    conn = {client: p, queue: Promise.resolve()}
+    agent.connections.set(key, conn)
+    // On connection failure, remove from map so next call retries
+    p.catch(() => {
+      const cur = agent.connections.get(key)
+      if (cur && cur.client === p) agent.connections.delete(key)
+    })
+  }
+  return conn.client
+}
+
+function reconnectClient(agent: XFTPClientAgent, server: XFTPServer): Promise<XFTPClient> {
+  const key = formatXFTPServer(server)
+  const old = agent.connections.get(key)
+  // Close old client (fire-and-forget)
+  old?.client.then(c => c.transport.close(), () => {})
+  // Replace with new connection promise — all concurrent callers will await this
+  // Queue survives reconnect — pending operations stay ordered
+  const p = connectXFTP(server)
+  const conn: ServerConnection = {client: p, queue: old?.queue ?? Promise.resolve()}
+  agent.connections.set(key, conn)
+  p.catch(() => {
+    const cur = agent.connections.get(key)
+    if (cur && cur.client === p) agent.connections.delete(key)
+  })
+  return p
+}
+
+function closeXFTPServerClient(agent: XFTPClientAgent, server: XFTPServer): void {
+  const key = formatXFTPServer(server)
+  const conn = agent.connections.get(key)
+  if (conn) {
+    agent.connections.delete(key)
+    conn.client.then(c => c.transport.close(), () => {})
+  }
+}
+
+function closeXFTPAgent(agent: XFTPClientAgent): void {
+  for (const conn of agent.connections.values()) {
+    conn.client.then(c => c.transport.close(), () => {})
+  }
+  agent.connections.clear()
+}
+```
+
+**Precise semantics:**
+
+1. `getXFTPServerClient(agent, server)` — returns existing `conn.client` promise if present, otherwise creates a new `ServerConnection` with fresh connection and empty queue
+2. When error detected, first caller calls `reconnectClient` which replaces `conn.client` with a new connection promise. The queue is preserved across reconnect.
+3. All concurrent callers awaiting the OLD promise receive the error
+4. They then call `getXFTPServerClient` which returns the NEW promise
+5. If reconnection fails, auto-cleanup (`p.catch(() => delete)`) removes the entry so the next caller starts fresh
+
+**Stale error cleanup rule:** When a caller exhausts retries for a retriable error, it removes the failed entry from the map (only if no concurrent caller has already replaced it via `reconnectClient`). This prevents the next caller from receiving a stale rejected promise. Permanent errors (AUTH, NO_FILE, etc.) do NOT remove the connection — the transport is fine, only the command failed.
+
+```typescript
+function removeStaleConnection(
+  agent: XFTPClientAgent, server: XFTPServer, failedP: Promise<XFTPClient>
+): void {
+  const key = formatXFTPServer(server)
+  const conn = agent.connections.get(key)
+  // Only remove if current promise is the one that failed — not if already replaced by reconnect
+  if (conn && conn.client === failedP) {
+    agent.connections.delete(key)
+    failedP.then(c => c.transport.close(), () => {})
+  }
+}
+```
+
+**Per-server sequential queue:** `queue` is a `Promise<void>` — the tail of the sequential operation chain. Each new operation `.then()`s onto it. It's `void` because callers hold their own typed promises; the queue only tracks completion order:
+
+```typescript
+async function enqueueCommand<T>(
+  agent: XFTPClientAgent,
+  server: XFTPServer,
+  fn: () => Promise<T>   // no client param — fn uses command wrappers (agent+server)
+): Promise<T> {
+  const key = formatXFTPServer(server)
+  // Ensure connection exists (with auto-cleanup on failure)
+  await getXFTPServerClient(agent, server)
+  const conn = agent.connections.get(key)!  // guaranteed to exist after getXFTPServerClient
+  // Chain onto the queue — fn runs after previous operation completes
+  let resolve_: (v: T) => void, reject_: (e: any) => void
+  const result = new Promise<T>((res, rej) => { resolve_ = res; reject_ = rej })
+  conn.queue = conn.queue.then(
+    () => fn().then(resolve_!, reject_!),
+    () => fn().then(resolve_!, reject_!)
+  ).then(() => {}, () => {})  // swallow errors in the chain
+  return result
+}
+```
+
+Commands to the same server execute one at a time via the queue. Commands to different servers execute concurrently because each has its own queue. `enqueueCommand` provides sequencing; `sendXFTPCommand` (called inside `fn` via command wrappers) provides retry. They compose as: `enqueueCommand` sequences calls to wrappers that internally use `sendXFTPCommand`.
+
+**Download change:** Group chunks by server, process each server's chunks sequentially, servers in parallel. Uses `for` loop for per-server sequencing (same pattern as Stage 2 upload). `enqueueCommand` is available for cases where different callers target the same server.
+
+```typescript
+const byServer = new Map<string, FileChunk[]>()
+for (const chunk of resolvedFd.chunks) {
+  const srv = chunk.replicas[0]?.server ?? ""
+  if (!byServer.has(srv)) byServer.set(srv, [])
+  byServer.get(srv)!.push(chunk)
+}
+await Promise.all([...byServer.entries()].map(async ([srv, chunks]) => {
+  const server = parseXFTPServer(srv)
+  for (const chunk of chunks) {
+    const seed = decodePrivKeyEd25519(chunk.replicas[0].replicaKey)
+    const kp = ed25519KeyPairFromSeed(seed)
+    const raw = await downloadXFTPChunkRaw(agent, server, kp.privateKey, chunk.replicas[0].replicaId)
+    await onRawChunk({chunkNo: chunk.chunkNo, dhSecret: raw.dhSecret, nonce: raw.nonce, body: raw.body, digest: chunk.digest})
+    downloaded += chunk.chunkSize
+    onProgress?.(downloaded, resolvedFd.size)
+  }
+}))
+```
+
+### 3.6 Fix cache key
+
+**Bug:** `getXFTPServerClient` (client.ts:110) uses `"https://" + server.host + ":" + server.port` as cache key, ignoring `keyHash`. Two servers with same host:port but different keyHash share a cached connection, bypassing identity verification.
+
+**Fix:** Use `formatXFTPServer(server)` as cache key (includes keyHash). Already available in `protocol/address.ts:52-54`.
+
+```typescript
+// Before:
+const key = "https://" + server.host + ":" + server.port
+
+// After:
+const key = formatXFTPServer(server)
+```
+
+Note: With the redesign in 3.5, the cache key fix is inherent — the `connections` Map uses `formatXFTPServer(server)` everywhere.
+
+### 3.7 Phase 2: Multi-server upload with server selection and failover
+
+**Problem:** Current upload (`agent.ts:105-157`) takes a single `server: XFTPServer` and uploads ALL chunks to it. The 12 preset servers (6 SimpleX + 6 Flux) are pointless — only one is ever used.
+
+**Design goal:** Distribute chunks across servers. Retry FNEW on a different server if one fails. Once working servers are found, prefer them (heuristic: server unlikely to fail mid-process, more likely to be broken initially due to maintenance/downtime).
+
+**Reference implementation:** Haskell `Agent.hs:457-486` (`createChunk` / `createWithNextSrv`) + `Client.hs:2335-2385` (`getNextServer_` / `withNextSrv`).
+
+#### Haskell algorithm summary
+
+Two-stage architecture:
+
+1. **Allocate stage (serial per file in Haskell):** For each chunk, call FNEW on a randomly-selected server. If FNEW fails, pick a different server and retry. Track tried hosts to avoid retrying the same server. After all chunks are assigned to servers, spawn one upload worker per server.
+
+2. **Upload stage (parallel per server):** Each server worker uploads its assigned chunks sequentially (FPUT). On FPUT failure, retry on the same server with backoff (because the chunk replica already exists on that server). No server failover for FPUT.
+
+Server selection constraints (hierarchical, `getNextServer_` Client.hs:2335-2350):
+1. Prefer servers from unused operators (operator diversity)
+2. Prefer servers with unused hosts (host diversity)
+3. Random pick from the most-constrained candidate set
+4. If all exhausted, reset tried set and start over
+
+#### Web client adaptation
+
+The web client doesn't have operators or a database. Simplified algorithm with two stages:
+
+**Stage 1 — Allocate:** Create chunk records on servers (FNEW). Unlike Haskell which is serial here, web FNEW runs concurrently within a concurrency limit. FNEW is a small command — concurrent FNEW on the same connection is not a problem, and concurrent FNEW across servers improves upload startup time.
+
+**Stage 2 — Upload:** Upload chunk data (FPUT). Parallel across servers, sequential per server (reuses per-server queues from 3.5). FPUT retries on the same server with backoff — no server rotation because the chunk replica already exists on that server. Stage 2 reads chunk data by offset (via `readChunk`), so `SentChunk` must be extended with `chunkOffset: number` (from ChunkSpec).
+
+```typescript
+interface UploadState {
+  untriedServers: XFTPServer[]    // servers not yet attempted — initially all servers
+  workingServers: XFTPServer[]    // servers that succeeded FNEW
+}
+
+const MAX_FNEW_ATTEMPTS = 5  // per chunk: try up to 5 different servers
+
+async function uploadFile(
+  agent: XFTPClientAgent,
+  allServers: XFTPServer[],
+  encrypted: EncryptedFileMetadata,
+  options?: UploadOptions
+): Promise<UploadResult> {
+  const state: UploadState = {untriedServers: [...allServers], workingServers: []}
+  const specs = prepareChunkSpecs(encrypted.chunkSizes)
+  const concurrency = options?.concurrency ?? 4
+
+  // Stage 1: Allocate — concurrent FNEW within concurrency limit
+  const sentChunks: SentChunk[] = new Array(specs.length)
+  const queue = specs.map((spec, i) => ({spec, chunkNo: i + 1, index: i}))
+  let idx = 0
+  async function allocateWorker() {
+    while (idx < queue.length) {
+      const item = queue[idx++]
+      const {server, chunk} = await createChunkWithFailover(
+        agent, allServers, state, concurrency, item.spec, item.chunkNo
+      )
+      sentChunks[item.index] = chunk
+    }
+  }
+  const allocateWorkers = Array.from(
+    {length: Math.min(concurrency, queue.length)},
+    () => allocateWorker()
+  )
+  await Promise.all(allocateWorkers)
+
+  // Stage 2: Upload — parallel across servers, sequential per server
+  // readChunk reads from the encrypted file by offset (same as Phase 1 uploadFile)
+  let uploaded = 0
+  const total = encrypted.chunkSizes.reduce((a, b) => a + b, 0)
+  const byServer = groupBy(sentChunks, c => formatXFTPServer(c.server))
+  await Promise.all([...byServer.entries()].map(async ([srvKey, chunks]) => {
+    for (const chunk of chunks) {
+      const chunkData = await readChunk(chunk.chunkOffset, chunk.chunkSize)
+      await uploadXFTPChunk(agent, chunk.server, chunk.senderKey, chunk.senderId, chunkData)
+      uploaded += chunk.chunkSize
+      options?.onProgress?.(uploaded, total)
+    }
+  }))
+
+  return buildDescriptions(encrypted, sentChunks)
+}
+```
+
+**`createChunkWithFailover`** — server selection with per-chunk retry limit:
+
+```typescript
+async function createChunkWithFailover(
+  agent: XFTPClientAgent,
+  allServers: XFTPServer[],
+  state: UploadState,
+  concurrency: number,
+  spec: ChunkSpec,
+  chunkNo: number
+): Promise<{server: XFTPServer, chunk: SentChunk}> {
+  const maxAttempts = Math.min(allServers.length, MAX_FNEW_ATTEMPTS)
+
+  for (let attempt = 0; attempt < maxAttempts; attempt++) {
+    const server = pickServer(allServers, state, concurrency)
+    try {
+      const chunk = await createAndPrepareChunk(agent, server, spec, chunkNo)
+      // Success — add to working set (if not already there)
+      if (!state.workingServers.some(s => formatXFTPServer(s) === formatXFTPServer(server))) {
+        state.workingServers.push(server)
+      }
+      return {server, chunk}
+    } catch (e) {
+      // Remove from working if it was there
+      state.workingServers = state.workingServers.filter(
+        s => formatXFTPServer(s) !== formatXFTPServer(server)
+      )
+      if (attempt === maxAttempts - 1) throw e
+    }
+  }
+  throw new Error("unreachable")
+}
+```
+
+**`pickServer`** — two-list selection:
+
+```typescript
+function pickServer(
+  allServers: XFTPServer[],
+  state: UploadState,
+  concurrency: number
+): XFTPServer {
+  // Once enough working servers found, only use those
+  if (state.workingServers.length >= concurrency) {
+    return randomPick(state.workingServers)
+  }
+  // Still exploring — pick from untried
+  if (state.untriedServers.length > 0) {
+    const idx = Math.floor(Math.random() * state.untriedServers.length)
+    return state.untriedServers.splice(idx, 1)[0]  // remove from untried
+  }
+  // All tried — reset untried to non-working servers and retry
+  state.untriedServers = allServers.filter(
+    s => !state.workingServers.some(w => formatXFTPServer(w) === formatXFTPServer(s))
+  )
+  if (state.untriedServers.length > 0) {
+    const idx = Math.floor(Math.random() * state.untriedServers.length)
+    return state.untriedServers.splice(idx, 1)[0]
+  }
+  // Every server is working — pick any working
+  return randomPick(state.workingServers)
+}
+```
+
+**Algorithm:** Two lists — `untriedServers` (initially all) and `workingServers` (initially empty). When `workingServers.length < concurrency`, pick from `untriedServers` (removing on pick). On FNEW success, add to `workingServers`. On FNEW failure, server is already removed from `untriedServers`; remove from `workingServers` if present. When `untriedServers` is empty, reset it to all non-working servers. Once `workingServers.length >= concurrency`, pick randomly only from `workingServers`.
+
+**Termination condition:** Each chunk tries at most `min(serverCount, 5)` different servers. If all attempts fail, the chunk fails and the upload fails with the last error. Rationale: if 5 out of 12 servers are down, something systemic is wrong and continuing is unlikely to help. Timeouts count as failures — the timed-out server is removed from working and a different server is picked next.
+
+**Key differences from Haskell:**
+- No operator concept — just host diversity via random selection
+- No database — state tracked in-memory during upload
+- FNEW runs concurrently (Haskell is serial) — improves startup time
+- FNEW is cheap and retried with server rotation; FPUT retries on same server
+
+**Download changes (also Phase 2):** Default concurrency should be 4 (matching Haskell). Download already groups by server in 3.5. If `replicas[0]` download fails, try `replicas[1]`, `replicas[2]`, etc. (fallback across replicas).
+
+## 4. Implementation Plan
+
+### Phase 1: Error handling and connection resilience
+
+Steps are ordered by dependency and should be implemented one by one.
+
+#### Step 1: Fix cache key (3.6)
+- Change cache key to `formatXFTPServer(server)` in `getXFTPServerClient` and `closeXFTPServerClient`
+- Add import for `formatXFTPServer`
+- Run existing tests to verify no regression
+
+#### Step 2: Typed error detection for padded server errors (3.2 client-side)
+- Add `XFTPRetriableError` class
+- In `sendXFTPCommand`, detect padded error strings before `decodeTransmission`
+- Classify `FRErr` responses as retriable or permanent with human-readable messages
+- Run existing tests
+
+#### Step 3: Fetch timeout (3.3)
+- Add `TransportConfig` with `timeoutMs`
+- Thread config through `createTransport` → `connectXFTP` → command wrappers
+- Add `AbortController` to browser `fetch()` and `setTimeout` to Node.js HTTP/2
+- Add vitest test: timeout triggers after configured duration
+- Run existing tests
+
+#### Step 4: Connection state with Promise-based lock and per-server queues (3.5)
+- Introduce `ServerConnection` record: `{client: Promise<XFTPClient>, queue: Promise<void>}`
+- Replace `XFTPClientAgent.clients: Map<string, XFTPClient>` with `connections: Map<string, ServerConnection>`
+- Implement `reconnectClient` — replaces `conn.client` with new promise, preserves queue
+- Implement `enqueueCommand` — chains operation onto server's queue
+- Implement `removeStaleConnection` — removes entry only if current promise is the failed one
+- Auto-cleanup: `p.catch(() => delete)` removes failed connections so next caller starts fresh
+- Adapt `closeXFTPServerClient` and `closeXFTPAgent`
+- Add vitest tests:
+  - Concurrent calls to same server produce single connection
+  - Failed promise is cleaned up, next caller gets fresh connection
+
+#### Step 5: Automatic retry in sendXFTPCommand (3.2)
+- Add retry loop with reconnect
+- Change `sendXFTPCommand` signature: takes `agent + server` instead of `client`; export it (needed by tests and by agent.ts callers)
+- Rename current `sendXFTPCommand` → `sendXFTPCommandOnce` (private); add padded error detection + FRErr classification (throw `XFTPRetriableError` for SESSION/HANDSHAKE, `XFTPPermanentError` for AUTH/NO_FILE/etc.)
+- All command wrappers (`createXFTPChunk`, `uploadXFTPChunk`, etc.) pass agent + server
+- Update agent.ts call sites: remove `getXFTPServerClient` calls before command wrappers (in `uploadFile`, `uploadRedirectDescription`, `downloadFileRaw`, `resolveRedirect`, `deleteFile`)
+- Max 3 retries for retriable errors, immediate throw for permanent
+- On retriable error: call `reconnectClient` and retry. On retriable error exhausted: call `removeStaleConnection` to clean up. On permanent error: throw immediately without touching connection
+- Add vitest tests:
+  - Server started with delay → first attempt fails, retry succeeds
+  - 3 retries exhausted → error propagates with human-readable message
+  - Non-retriable error (AUTH) → no retry, immediate failure
+
+#### Step 6: Server-side stale session handling (3.1)
+- Add one guard to `Nothing` branch: `sniUsed && not webHello -> throwE SESSION`
+- Remove debug `hPutStrLn stderr` lines (all 6 occurrences in dispatch)
+- All other branches unchanged
+- Run Haskell tests + Playwright tests
+
+#### Step 7: Download with per-server grouping
+- Modify `downloadFileRaw` to group chunks by server, sequential within each server (`for` loop), parallel across servers (`Promise.all`)
+- Add vitest test: concurrent downloads from different servers run in parallel
+
+#### Step 8: UI error improvements (3.4)
+- Temporary errors: auto-retry loop (3 attempts), then show human-readable diagnosis + manual retry button
+- Permanent errors: show human-readable error, NO retry button
+- Manual retry resumes from last successful chunk (not full restart)
+
+#### Step 9: Remove debug logging
+- Remove all `console.log('[DEBUG ...]')` and `hPutStrLn stderr "DEBUG ..."` lines
+- Keep `console.error('[XFTP] ...')` error logging
+
+### Phase 2: Multi-server upload
+
+Implement after Phase 1 is complete and tested.
+
+#### Step 10: Multi-server upload with failover (3.7)
+- Extend `SentChunk` with `chunkOffset: number` (from ChunkSpec) and `server: XFTPServer` (assigned during allocate) — Stage 2 reads data by offset and groups chunks by server
+- Change `uploadFile` signature: takes `allServers: XFTPServer[]` instead of single `server`
+- Implement `UploadState` with `untriedServers` and `workingServers`
+- Implement `createChunkWithFailover` and `pickServer`: two-list selection (untried → working once enough found), max `min(serverCount, 5)` attempts per chunk
+- Allocate stage: concurrent FNEW within concurrency limit (default 4)
+- Upload stage: parallel across servers, sequential per server (reuse queue from Step 7)
+- Update `web/upload.ts`: pass `getServers()` instead of `pickRandomServer(getServers())`
+- Update description building: each chunk references its actual server
+- Add vitest tests:
+  - File split across N servers (verify different servers in description)
+  - One server down → chunks redistributed to others
+  - All servers down → error after exhausting 5 attempts per chunk
+
+#### Step 11: Download concurrency and replica fallback
+- Change default download concurrency from 1 to 4
+- If `replicas[0]` download fails, try `replicas[1]`, `replicas[2]`, etc.
+- Uses per-server queues from Step 7
+
+## 5. Testing Plan
+
+### Principle
+
+Prefer low-level vitest tests over Playwright E2E. Each new function gets one focused test. Pure functions tested without mocks; connection management tested with mock `connectXFTP`; server behavior tested with real server. Total: 13 tests across 4 files.
+
+Tests A-C run in browser context (`@vitest/browser` with Chromium headless), configured in `vitest.config.ts`. Test D (integration) requires a separate Node.js vitest config since it uses `node:http2`. Existing `globalSetup.ts` provides a real XFTP server for integration tests.
+
+### Test file A: `test/errors.test.ts` — pure, no server
+
+Tests error classification and padded error detection (Steps 2, 5).
+
+**T1. `isRetriable` classifies errors correctly**
+```typescript
+// Retriable:
+expect(isRetriable(new XFTPRetriableError("SESSION"))).toBe(true)
+expect(isRetriable(new XFTPRetriableError("HANDSHAKE"))).toBe(true)
+expect(isRetriable(new TypeError("fetch failed"))).toBe(true)          // network error
+expect(isRetriable(Object.assign(new Error(), {name: "AbortError"}))).toBe(true)  // timeout
+// Not retriable:
+expect(isRetriable(new XFTPPermanentError("AUTH", "..."))).toBe(false)
+expect(isRetriable(new XFTPPermanentError("NO_FILE", "..."))).toBe(false)
+expect(isRetriable(new XFTPPermanentError("INTERNAL", "..."))).toBe(false)
+```
+
+**T2. `categorizeError` produces human-readable messages**
+```typescript
+// categorizeError receives thrown errors (from sendXFTPCommandOnce or transport)
+const e = categorizeError(new XFTPPermanentError("AUTH", "File is invalid, expired, or has been removed"))
+expect(e.message).toContain("expired")
+// Verify every permanent error type maps to a non-empty human-readable message
+for (const errType of ["AUTH", "NO_FILE", "SIZE", "QUOTA", "BLOCKED", "DIGEST", "INTERNAL"]) {
+  expect(humanReadableMessage({type: errType}).length).toBeGreaterThan(0)
+}
+// Retriable errors also get human-readable messages after exhaustion
+const re = categorizeError(new XFTPRetriableError("SESSION"))
+expect(re.message).toContain("expired")  // "Session expired, reconnecting..."
+```
+
+**T3. Padded error detection extracts error string from padded block**
+```typescript
+import {blockPad, blockUnpad} from '../src/protocol/transmission.js'
+// Simulate server sending padded "SESSION"
+const padded = blockPad(new TextEncoder().encode("SESSION"))
+const raw = blockUnpad(padded)
+expect(raw.length).toBeLessThan(20)
+expect(new TextDecoder().decode(raw)).toBe("SESSION")
+// Normal transmission block (batch count + large-encoded data) is NOT a short string
+const sessionId = new Uint8Array(32)  // dummy
+const normalBlock = encodeTransmission(sessionId, new Uint8Array(0), new Uint8Array(0), encodePING())
+const normalRaw = blockUnpad(normalBlock)
+expect(normalRaw.length).toBeGreaterThan(20)  // not mistaken for padded error
+```
+
+### Test file B: `test/connection.test.ts` — mock connectXFTP, no server
+
+Tests connection management functions (Steps 4, 5). Uses `vi.mock` to replace `connectXFTP` with a controllable promise factory.
+
+**T4. `getXFTPServerClient` coalesces concurrent calls**
+```typescript
+// Mock connectXFTP to return a deferred promise
+const {promise, resolve} = promiseWithResolvers<XFTPClient>()
+vi.mocked(connectXFTP).mockReturnValueOnce(promise)
+const agent = newXFTPAgent()
+const p1 = getXFTPServerClient(agent, server)
+const p2 = getXFTPServerClient(agent, server)
+expect(p1).toBe(p2)  // same promise, single connection
+resolve(mockClient)
+expect(await p1).toBe(mockClient)
+```
+
+**T5. `getXFTPServerClient` auto-cleans failed connections**
+```typescript
+vi.mocked(connectXFTP).mockReturnValueOnce(Promise.reject(new Error("down")))
+const agent = newXFTPAgent()
+const p1 = getXFTPServerClient(agent, server)
+await expect(p1).rejects.toThrow("down")
+// After microtask, entry is removed
+await new Promise(r => setTimeout(r, 0))
+expect(agent.connections.has(formatXFTPServer(server))).toBe(false)
+// Next call creates fresh connection
+vi.mocked(connectXFTP).mockReturnValueOnce(Promise.resolve(mockClient))
+const p2 = getXFTPServerClient(agent, server)
+expect(p2).not.toBe(p1)
+```
+
+**T6. `removeStaleConnection` respects promise identity**
+```typescript
+const agent = newXFTPAgent()
+const p1 = Promise.resolve(mockClient)
+agent.connections.set(key, {client: p1, queue: Promise.resolve()})
+// Replace with reconnect
+const p2 = Promise.resolve(mockClient2)
+agent.connections.set(key, {client: p2, queue: Promise.resolve()})
+// removeStaleConnection with old promise does NOT remove new entry
+removeStaleConnection(agent, server, p1)
+expect(agent.connections.has(key)).toBe(true)
+expect(agent.connections.get(key)!.client).toBe(p2)
+// removeStaleConnection with current promise removes it
+removeStaleConnection(agent, server, p2)
+expect(agent.connections.has(key)).toBe(false)
+```
+
+**T7. `reconnectClient` replaces promise but preserves queue**
+```typescript
+const agent = newXFTPAgent()
+const origQueue = Promise.resolve()
+agent.connections.set(key, {client: Promise.resolve(mockClient), queue: origQueue})
+vi.mocked(connectXFTP).mockReturnValueOnce(Promise.resolve(mockClient2))
+reconnectClient(agent, server)
+const conn = agent.connections.get(key)!
+expect(await conn.client).toBe(mockClient2)  // new client
+expect(conn.queue).toBe(origQueue)            // queue preserved
+```
+
+**T8. Retry loop: retriable error triggers reconnect, permanent error does not**
+
+Mock approach: `vi.mock('../src/client.js')` to mock `connectXFTP` (exported). `reconnectClient` is not exported — its behavior is controlled indirectly via `connectXFTP` mock (it calls `connectXFTP` internally). Verify retry count via `connectXFTP` call count. Note: vitest module mocking may need adjustment depending on ESM transform behavior — if intra-module calls bypass the mock, extract `connectXFTP` to a separate module or use dependency injection for testing.
+
+```typescript
+// Script: first connectXFTP returns client whose post throws retriable,
+// second connectXFTP (from reconnect) returns client whose post succeeds
+vi.mocked(connectXFTP)
+  .mockResolvedValueOnce({
+    ...mockClient,
+    transport: { post: async () => { throw new XFTPRetriableError("SESSION") }, close: () => {} }
+  })
+  .mockResolvedValueOnce({
+    ...mockClient,
+    transport: { post: async () => okResponseBlock, close: () => {} }
+  })
+
+const agent = newXFTPAgent()
+const result = await sendXFTPCommand(agent, server, dummyKey, dummyId, encodePING())
+expect(result.response.type).toBe("FROk")
+expect(vi.mocked(connectXFTP)).toHaveBeenCalledTimes(2)  // initial + 1 reconnect
+
+// Reset — all 3 retries exhausted: connectXFTP called 3 times (initial + 2 reconnects)
+vi.mocked(connectXFTP).mockClear()
+vi.mocked(connectXFTP).mockResolvedValue({
+  ...mockClient,
+  transport: { post: async () => { throw new XFTPRetriableError("SESSION") }, close: () => {} }
+})
+const agent2 = newXFTPAgent()
+await expect(sendXFTPCommand(agent2, server, dummyKey, dummyId, encodePING()))
+  .rejects.toThrow(/reconnecting|expired/)
+expect(vi.mocked(connectXFTP)).toHaveBeenCalledTimes(3)  // initial + 2 reconnects
+
+// Reset — permanent error: connectXFTP called once (initial only, no reconnect)
+vi.mocked(connectXFTP).mockClear()
+vi.mocked(connectXFTP).mockResolvedValue({
+  ...mockClient,
+  transport: { post: async () => authErrorBlock, close: () => {} }
+})
+const agent3 = newXFTPAgent()
+await expect(sendXFTPCommand(agent3, server, dummyKey, dummyId, encodePING()))
+  .rejects.toThrow(/expired/)
+expect(vi.mocked(connectXFTP)).toHaveBeenCalledTimes(1)  // initial only, no reconnect
+```
+
+### Test file C: `test/server-selection.test.ts` — pure, no server
+
+Tests `pickServer` state machine (Step 10). Determinism: seed `Math.random` or test invariants not specific picks.
+
+**T9. `pickServer` picks from untried when working < concurrency**
+```typescript
+const servers = [s1, s2, s3, s4, s5]
+const state: UploadState = {untriedServers: [...servers], workingServers: []}
+const picked = pickServer(servers, state, 4)
+// picked is from untried, and was removed from untried
+expect(state.untriedServers.length).toBe(4)
+expect(state.untriedServers).not.toContainEqual(picked)
+```
+
+**T10. `pickServer` picks only from working when working >= concurrency**
+```typescript
+const state: UploadState = {
+  untriedServers: [s5],  // still has untried
+  workingServers: [s1, s2, s3, s4]
+}
+const picked = pickServer(servers, state, 4)
+// Must pick from working, NOT from untried
+expect([s1, s2, s3, s4]).toContainEqual(picked)
+expect(state.untriedServers.length).toBe(1)  // untried unchanged
+```
+
+**T11. `pickServer` resets untried when exhausted**
+```typescript
+const state: UploadState = {
+  untriedServers: [],        // all tried
+  workingServers: [s1, s2]   // only 2 working, concurrency=4
+}
+const picked = pickServer(servers, state, 4)
+// Should have reset untried to non-working servers and picked from them
+expect([s3, s4, s5]).toContainEqual(picked)
+expect(state.untriedServers.length).toBe(2)  // 3 non-working minus 1 picked
+```
+
+### Test file D: `test/integration.test.ts` — real server, Node.js mode
+
+Requires separate vitest config with `browser: {enabled: false}` since these tests use `node:http2` directly. Alternatively, add `test/vitest.node.config.ts` that includes only `test/integration.test.ts` and runs in Node.js.
+
+**T12. Stale session returns padded SESSION error (requires Step 6)**
+```typescript
+import http2 from 'node:http2'
+// Connect and handshake normally via the client
+const client = await connectXFTP(server)
+// Create a raw HTTP/2 session (new TLS SessionId, no handshake state on server)
+const session = http2.connect(client.baseUrl, {rejectUnauthorized: false})
+// Build a dummy command block using the old client's sessionId.
+// Content doesn't matter — server detects stale session before parsing command.
+const dummyKey = new Uint8Array(64)  // Ed25519 private key (dummy)
+const dummyId = new Uint8Array(24)   // entity ID (dummy)
+const cmdBlock = encodeAuthTransmission(client.sessionId, new Uint8Array(0), dummyId, encodePING(), dummyKey)
+const resp = await new Promise<Uint8Array>((resolve, reject) => {
+  const req = session.request({":method": "POST", ":path": "/"})
+  const chunks: Buffer[] = []
+  req.on("data", (c: Buffer) => chunks.push(c))
+  req.on("end", () => resolve(new Uint8Array(Buffer.concat(chunks))))
+  req.on("error", reject)
+  req.end(Buffer.from(cmdBlock))
+})
+// Server should return padded "SESSION" (not crash, not "HANDSHAKE")
+const raw = blockUnpad(resp.subarray(0, XFTP_BLOCK_SIZE))
+expect(new TextDecoder().decode(raw)).toBe("SESSION")
+session.close()
+closeXFTP(client)
+```
+
+**T13. Fetch timeout fires within configured duration**
+```typescript
+// connectXFTP with 1ms timeout — handshake requires multiple round trips,
+// so even on localhost it will exceed 1ms and trigger abort
+await expect(
+  connectXFTP(server, {timeoutMs: 1})
+).rejects.toThrow(/abort|timeout/i)
+```
+
+### What existing tests already cover (no new tests needed)
+
+| Behavior | Covered by |
+|----------|-----------|
+| Cache key fix (Step 1) | Existing round-trip test — uses `formatXFTPServer` after refactor |
+| Basic upload/download | 24 Playwright tests + 1 vitest browser test |
+| File size limits, unicode filenames | Playwright edge case tests |
+| Server startup/teardown | `globalSetup.ts` / `globalTeardown.ts` |
+| Handshake + identity verification | `connectXFTP` in existing round-trip test |
+
+### Test ordering
+
+Tests must be added alongside their implementation step:
+- **Step 2**: Add T1, T2, T3 (test/errors.test.ts)
+- **Step 3**: Add T13 (test/integration.test.ts) — requires Node.js vitest config
+- **Step 4**: Add T4, T5, T6, T7 (test/connection.test.ts)
+- **Step 5**: Add T8 (test/connection.test.ts)
+- **Step 6**: Add T12 (test/integration.test.ts) — requires server change + Node.js vitest config
+- **Step 10**: Add T9, T10, T11 (test/server-selection.test.ts)
+
+## 6. Context for Implementation Sessions
+
+### Files to re-read on session start
+
+**TypeScript (xftp-web/src/):**
+- `client.ts` — `XFTPClient`, `XFTPClientAgent`, `getXFTPServerClient`, `closeXFTPServerClient`, `connectXFTP`, `sendXFTPCommand`, `createBrowserTransport`, `createNodeTransport`, all command wrappers
+- `agent.ts` — `uploadFile`, `downloadFileRaw`, `downloadFile`, `resolveRedirect`, `encryptFileForUpload`
+- `protocol/transmission.ts` — `encodeAuthTransmission`, `decodeTransmission`, `blockPad`, `blockUnpad`
+- `protocol/commands.ts` — `XFTPErrorType`, `FileResponse`, `decodeResponse`, `decodeXFTPError`
+- `protocol/handshake.ts` — `decodeServerHandshake` (padded error detection heuristic)
+- `protocol/address.ts` — `XFTPServer`, `parseXFTPServer`, `formatXFTPServer`
+- `web/upload.ts` — UI error handling, retry button
+- `web/download.ts` — UI error handling, retry button
+- `web/servers.ts` — `getServers`, `pickRandomServer`
+
+**TypeScript (xftp-web/test/):**
+- `browser.test.ts` — vitest Node.js test template (uses real Haskell server)
+- `globalSetup.ts` — server startup, config generation, port file
+- `page.spec.ts` — Playwright page tests
+
+**Haskell (reference for multi-server):**
+- `src/Simplex/FileTransfer/Agent.hs` — `createChunk` (lines 457-486, allocate stage), `runXFTPSndPrepareWorker` (lines 391-430, serial allocate in Haskell), `runXFTPSndWorker` (lines 494-548, per-server upload worker)
+- `src/Simplex/Messaging/Agent/Client.hs` — `getNextServer_` (lines 2335-2350), `withNextSrv` (lines 2366-2385), `pickServer` (lines 2309-2314)
+
+**Haskell (server):**
+- `src/Simplex/FileTransfer/Server.hs` — `xftpServerHandshakeV1` (lines 165-244), `processRequest` (lines 403-435)
+- `src/Simplex/Messaging/Protocol.hs` — `tDecodeServer` (lines 2239-2265) — sessionId verification at line 2242
+
+### Key design constraints
+
+1. `tDecodeServer` (Protocol.hs:2242) verifies `sessId == sessionId` — commands signed with old sessionId WILL fail on new connection
+2. Server generates per-session DH key in `processHello` (Server.hs:207) — cannot be shared across sessions
+3. `fetch()` provides zero control over HTTP/2 connection reuse — browser decides
+4. `xftp-web-hello` header is only checked in dispatch (Server.hs:192), NOT inside `processHello`
+5. Handshake-phase errors are raw padded strings; command-phase errors are proper ERR transmissions
+6. Ed25519 signature verification (`TASignature` path, Protocol.hs:1314) does NOT use `thAuth` — but SMP will
+7. Reconnect must re-handshake to get new sessionId AND new server DH key
+8. The new `throwE SESSION` guard (Step 6) sends a raw padded "SESSION" string — no sessionId framing. Client detects this via padded error heuristic (section 3.2), not via sessionId mismatch
+9. FNEW is cheap (creates chunk record on server) — retry with different server on failure
+10. FPUT retries on same server (chunk replica already exists there) — close connection + backoff
+
+## 7. Plan Maintenance
+
+This plan must be updated as implementation proceeds:
+- Mark completed steps with date
+- Record any deviations from the plan with rationale
+- Add new issues discovered during implementation
+- Update file references if code moves

rfcs/2026-01-30-send-file-page/2026-02-12-xftp-cli-web-link-compat.md

@@ -0,0 +1,327 @@
+# CLI-Web Link Compatibility
+
+## Problem
+
+CLI and web clients are isolated: CLI outputs `.xftp` description files, web outputs
+`https://host/#<encoded>` links. A file uploaded via one cannot be downloaded via the other.
+
+## Solution Summary
+
+Make CLI produce and consume web-compatible links so that:
+- CLI `send` always outputs a web link (in addition to `.xftp` files)
+- CLI `recv` accepts a web link URL as input (alternative to `.xftp` file path)
+- Browser can download files uploaded by CLI and vice versa
+
+The web page host is derived from the XFTP server address - the server that hosts the file
+also hosts the download page. Making XFTP servers actually serve the web page is a separate
+concern (not covered here), but the link format anticipates it.
+
+The YAML file description format is already identical between CLI and web.
+The only gap is the URI encoding layer: DEFLATE-raw compression + base64url + URL structure.
+
+## Current State
+
+### Web link format
+
+```
+https://<xftp-server-host>/#<base64url(deflateRaw(YAML))>
+```
+
+Encoding chain (agent.ts:64-68):
+1. `encodeFileDescription(fd)` -> YAML string
+2. `TextEncoder.encode(yaml)` -> bytes
+3. `pako.deflateRaw(bytes)` -> compressed
+4. `base64urlEncode(compressed)` -> URI fragment (no `#`)
+
+For multi-chunk files exceeding ~400 chars in URI, a redirect description is uploaded:
+the real file description is encrypted, uploaded as a separate XFTP file, and a smaller
+"redirect" description (pointing to it) is put in the URI.
+
+### CLI file format
+
+```
+xftp send FILE -> writes rcv1.xftp (raw YAML), snd.xftp.private
+xftp recv FILE.xftp -> reads raw YAML from file
+```
+
+No URI support. No compression. No redirect descriptions.
+
+### Existing Haskell `FileDescriptionURI`
+
+`Description.hs:243-266` defines a `simplex:/file#/?desc=<URL-encoded raw YAML>` format.
+This is the SimpleX Chat app format - NOT the web page format. It uses URL-encoded raw YAML
+(no DEFLATE compression), and has a different URL structure.
+
+## Detailed Tech Design
+
+### 1. File Header (Filename) Compatibility
+
+The filename is carried **inside the encrypted file data**, not in the file description YAML.
+Both CLI and web use the same `FileHeader` structure and binary encoding - full interop.
+
+#### FileHeader type
+
+Haskell (`Types.hs:36-46`):
+```haskell
+data FileHeader = FileHeader { fileName :: Text, fileExtra :: Maybe Text }
+instance Encoding FileHeader where
+  smpEncode FileHeader {fileName, fileExtra} = smpEncode (fileName, fileExtra)
+```
+
+TypeScript (`crypto/file.ts:11-24`):
+```typescript
+interface FileHeader { fileName: string; fileExtra: string | null }
+function encodeFileHeader(hdr: FileHeader): Uint8Array {
+  return concatBytes(encodeString(hdr.fileName), encodeMaybe(encodeString, hdr.fileExtra))
+}
+```
+
+Both produce identical binary: `[1-byte UTF-8 length][fileName bytes]['0']` (for null fileExtra).
+Max filename: 255 UTF-8 bytes (1-byte length prefix).
+
+#### Encrypted file structure
+
+Both CLI and web produce the same encrypted stream:
+```
+XSalsa20-Poly1305 encrypted:
+  [8-byte Int64 fileSize] [FileHeader] [file content] ['#' padding]
+  + [16-byte auth tag]
+
+Where fileSize = len(FileHeader) + len(file content)
+```
+
+The 8-byte length prefix and padding are handled identically:
+- Haskell: `Crypto.hs:43-56` (`encryptFile`) / `Crypto.hs:81-87` (`decryptFirstChunk`)
+- TypeScript: `crypto/file.ts:51-70` (`encryptFile`) / `crypto/file.ts:81-94` (`decryptChunks`)
+
+On decryption, `unPadLazy`/`splitLen` strips the 8-byte length prefix, then `parseFileHeader`
+extracts the filename from the remaining decrypted bytes (up to 1024 bytes examined, both sides).
+
+#### CLI upload: sets real filename (ok)
+
+`Client/Main.hs:246-247,273`:
+```haskell
+let (_, fileNameStr) = splitFileName filePath
+    fileName = T.pack fileNameStr
+...
+    fileHdr = smpEncode FileHeader {fileName, fileExtra = Nothing}
+```
+
+Extracts the actual filename from the path and embeds it in the encrypted header.
+
+#### CLI download: uses filename from header (ok)
+
+`Crypto.hs:62-66` (single chunk) / `Crypto.hs:72-74` (multi-chunk):
+```haskell
+(FileHeader {fileName}, rest) <- parseFileHeader decryptedContent
+destFile <- withExceptT FTCEFileIOError $ getDestFile fileName
+```
+
+`Client/Main.hs:435-441` (`getFilePath`):
+- If output dir specified: saves to `<dir>/<fileName>`
+- If no dir: saves to `~/Downloads/<fileName>`
+
+The filename from the decrypted header determines the output file name.
+
+#### Web upload: sets real filename (ok)
+
+`upload.ts:121` -> `agent.ts:86`:
+```typescript
+const fileHdr = encodeFileHeader({fileName, fileExtra: null})
+```
+
+Where `fileName` comes from `file.name` (browser File API).
+
+#### Web download: uses filename from header (ok)
+
+`download.ts:97,102`:
+```typescript
+const fileName = sanitizeFileName(header.fileName)
+a.download = encodeURIComponent(fileName)
+```
+
+The web client additionally sanitizes the filename (strips path separators, control chars,
+bidi overrides, limits to 255 chars).
+
+#### Web redirect description: empty filename (correct)
+
+`agent.ts:193`: `encryptFileForUpload(yamlBytes, "")` - redirect descriptions use empty filename
+because they are internal artifacts, not user files. This is handled correctly on both sides:
+the redirect content is decrypted and parsed as YAML, not saved as a file.
+
+#### Cross-client interop: fully compatible (ok)
+
+| Scenario | Filename flow | Status |
+|----------|--------------|--------|
+| CLI upload -> CLI download | `splitFileName` -> header -> `getDestFile` | Works |
+| Web upload -> Web download | `File.name` -> header -> `sanitizeFileName` | Works |
+| CLI upload -> Web download | `splitFileName` -> header -> `sanitizeFileName` | **Compatible** |
+| Web upload -> CLI download | `File.name` -> header -> `getDestFile` | **Compatible** |
+
+The binary encoding is identical (smpEncode). No changes needed for filename interop.
+The CLI should consider adding filename sanitization similar to the web client for safety.
+
+### 2. Web Link Host Derivation
+
+The web page URL domain comes from the XFTP server address, not from a CLI flag:
+
+- **Non-redirected description**: use the server host of the first chunk's first replica.
+  E.g., `xftp://abc=@xftp1.simplex.im` -> `https://xftp1.simplex.im/#<encoded>`
+
+- **Redirected description**: use the server host of the redirect chunk (the outer description's
+  chunk that stores the encrypted inner description).
+
+The server address format is `xftp://<keyhash>@<host>[,<host2>,...][:<port>]`.
+The web link uses `https://<host>` (port 443 implied).
+
+This means the CLI does not need a `--web-url` flag - the server address fully determines
+the link. The XFTP server serving the web page is a separate deployment concern.
+
+### 3. Web URI Encoding/Decoding in Haskell
+
+Add two functions (new module or in `Description.hs`):
+
+```haskell
+-- Encode file description as web URI fragment (no leading #)
+encodeWebURI :: FileDescription 'FRecipient -> ByteString
+-- 1. Y.encode . encodeFileDescription -> YAML bytes
+-- 2. deflateRaw (raw DEFLATE, no zlib/gzip header) via zlib package
+-- 3. base64url encode (with padding, matching Data.ByteString.Base64.URL)
+
+-- Decode web URI fragment (no leading #) to file description
+decodeWebURI :: ByteString -> Either String (ValidFileDescription 'FRecipient)
+-- 1. base64url decode
+-- 2. inflateRaw (raw DEFLATE decompress)
+-- 3. Y.decodeEither' -> YAMLFileDescription -> FileDescription
+-- 4. validateFileDescription
+
+-- Build full web link from file description
+-- Extracts server host from first chunk replica (or redirect chunk)
+fileWebLink :: FileDescription 'FRecipient -> (String, ByteString)
+-- Returns (webHost, uriFragment)
+-- Caller assembles: "https://" <> webHost <> "/#" <> uriFragment
+```
+
+**Dependency**: Add `zlib` to `simplexmq.cabal` (for raw DEFLATE).
+The codebase already has `zstd` for message compression - `zlib` is standard and small.
+
+The `zlib` Haskell package provides `Codec.Compression.Zlib.Raw` for raw DEFLATE
+(no header/trailer), matching `pako.deflateRaw()` / `pako.inflateRaw()`.
+
+### 4. Redirect Description Support
+
+The CLI currently does NOT create redirect descriptions. For single-server single-recipient
+uploads, most file descriptions fit in a reasonable URI even for multi-chunk files. But for
+large files (many chunks x long server hostnames), the URI can exceed practical limits.
+
+**Approach**: Match the web client threshold.
+- After encoding the URI, if `length > 400` and chunks > 1, upload a redirect description.
+- The redirect upload uses the same XFTP upload flow: encrypt YAML -> upload as file -> create
+  outer description pointing to it.
+- This matches `agent.ts:152-155` exactly.
+- The redirect chunk's server becomes the web link host.
+
+For CLI download from a redirect URI, the existing `cliReceiveFile` needs extension:
+- After decoding the file description, check `redirect` field.
+- If present: download and decrypt the redirect chunks first to get the inner description,
+  then download the actual file using the inner description.
+- The web client already does this (`resolveRedirect` in agent.ts:320-346).
+
+### 5. CLI Command Changes
+
+#### `xftp send` - always output web link
+
+```
+xftp send FILE [DIR] [-n COUNT] [-s SERVERS]
+```
+
+- Upload file as usual
+- Generate web link: `https://<server-host>/#<encodeWebURI(rcvDescription)>`
+- If URI exceeds threshold, upload redirect description first
+- Print web link to stdout (in addition to `.xftp` file paths)
+- Only generates link for the first recipient (web links are single-recipient)
+
+**Output change**:
+```
+Sender file description: ./file.xftp/snd.xftp.private
+Pass file descriptions to the recipient(s):
+./file.xftp/rcv1.xftp
+
+Web link:
+https://xftp1.simplex.im/#eJy0VduO2zYQ...
+```
+
+#### `xftp recv` - accept URL as input
+
+```
+xftp recv <FILE.xftp | URL> [DIR]
+```
+
+- If input starts with `http://` or `https://`, extract hash fragment after `#`
+- Decode: base64url -> inflateRaw -> YAML -> FileDescription
+- Resolve redirect if present
+- Download and decrypt as usual
+
+The URL must be quoted on the command line (`"https://...#..."`) because `#` is a shell
+comment character when unquoted.
+
+Implementation: modify `receiveP` parser to accept URL, add `decodeWebURI` path in
+`cliReceiveFile` alongside existing `getFileDescription'`.
+
+### 6. YAML Format Compatibility
+
+Already identical. The web `description.ts` explicitly matches Haskell `Data.Yaml` output:
+- Same field names (alphabetical key order)
+- Same base64url encoding for binary fields (with `=` padding)
+- Same server replica colon-delimited format: `chunkNo:replicaId:replicaKey[:digest][:chunkSize]`
+- Same size encoding (`kb`/`mb`/`gb` suffixes)
+- Same redirect structure
+
+**Verification**: The Playwright test suite already tests upload->download round-trips.
+Adding a cross-client test (CLI upload -> web download, or web upload -> CLI download) would
+validate interop end-to-end.
+
+### 7. Server Compatibility
+
+No server changes needed. Both clients use the same XFTP protocol (FGET, FPUT, FNEW, FACK, FDEL).
+The web client adds `xftp-web-hello: 1` header for the hello handshake, but the actual file
+operations are identical wire-format.
+
+The only consideration: CLI uses native HTTP/2 (via `http2` Haskell package), web uses
+browser `fetch()` API over HTTP/2. Both produce identical XFTP protocol frames.
+
+**Note**: Making XFTP servers actually serve the web download page at `https://<host>/` is a
+separate deployment/infrastructure task. This plan only establishes the link format convention
+so that links are ready to work once servers serve the page.
+
+## Implementation Plan
+
+### Phase 1: Web URI codec in Haskell
+
+1. Add `zlib` dependency to `simplexmq.cabal`
+2. Add `encodeWebURI` / `decodeWebURI` / `fileWebLink` to `Simplex.FileTransfer.Description`
+   (or a new `Simplex.FileTransfer.Description.WebURI` module)
+3. `fileWebLink` extracts host from first chunk's first replica server address
+4. Add unit tests: encode a known FileDescription, verify output matches web client encoding
+5. Add round-trip test: encode -> decode -> compare
+
+### Phase 2: CLI `recv` accepts URL
+
+1. Modify `ReceiveOptions` to accept `Either FilePath WebURL` for `fileDescription`
+2. In `cliReceiveFile`: if URL, extract fragment after `#`, call `decodeWebURI`
+3. Add redirect resolution: if `redirect /= Nothing`, download redirect chunks,
+   decrypt, parse inner description, then proceed with download
+4. Test: upload via web page -> copy link -> `xftp recv <link>`
+
+### Phase 3: CLI `send` outputs web link
+
+1. After upload, call `fileWebLink` to get (host, fragment)
+2. If fragment exceeds threshold, upload redirect description first, rebuild link
+3. Print `https://<host>/#<fragment>` to stdout
+4. Test: `xftp send FILE` -> open link in browser -> download
+
+### Phase 4: Cross-client integration test
+
+1. Add test: CLI send -> extract link from stdout -> Playwright browser download -> verify
+2. Add test: Playwright browser upload -> extract link -> CLI recv -> verify
+3. These can be shell-script or Haskell test-suite tests that spawn both clients

rfcs/2026-02-17-fix-subq-deadlock.md

@@ -0,0 +1,415 @@
+# Fix subQ deadlock: blocking writeTBQueue inside connLock
+
+## Problem
+
+Users report that message reception silently and permanently stops across all connections, with no error alerts. The app appears functional but no messages arrive. Recovery requires restart.
+
+Root cause: a deadlock between worker threads holding `connLock` and the `agentSubscriber` (sole `subQ` reader).
+
+### The deadlock mechanism
+
+`subQ` (`TBQueue ATransmission`, capacity 4096 on mobile / 1024 on desktop) is the single pipeline between the agent layer and the chat layer. The `agentSubscriber` thread (`Commands.hs:4373`) is its **sole reader**.
+
+Three code sites hold `connLock` and call blocking `writeTBQueue subQ` without a fullness check. When `subQ` is full, these block while holding the lock. If `agentSubscriber` simultaneously needs the same `connLock` (via `sendMessagesB_` → `withConnLocks`), it blocks too — creating a circular wait:
+
+- **Worker**: holds `connLock(X)`, waits for `subQ` space (needs `agentSubscriber` to read)
+- **agentSubscriber**: sole `subQ` reader, waits for `connLock(X)` (needs worker to release)
+- **Result**: permanent silent deadlock — no exception, no alert, all connections blocked
+
+### Confirmed deadlock scenarios
+
+**Scenario 1**: Delivery worker during queue rotation test
+
+```
+Delivery worker:                    agentSubscriber (sole subQ reader):
+  withConnLock(X) [2187]              readTBQueue subQ → processAgentMessageConn
+  ...DB operations...                 → sendPendingGroupMessages (on CON/SENT/QCONT)
+  notify → writeTBQueue subQ [2238]   → batchSendConnMessages → deliverMessagesB
+  [BLOCKED — subQ full]               → withAgent sendMessagesB [synchronous]
+                                      → sendMessagesB_ → withConnLocks({..X..}) [1708]
+                                      [BLOCKED — connLock(X) held]
+```
+
+**Scenario 2**: Async command worker during message ACK with notification
+
+```
+Async cmd worker:                   agentSubscriber (sole subQ reader):
+  tryWithLock "ICAck" [1930→1824]     readTBQueue subQ → processAgentMessageConn
+  → withConnLock(X)                   → sendPendingGroupMessages
+  → ack → ackQueueMessage [1899]      → sendMessagesB_ → withConnLocks({..X..})
+  → sendMsgNtf [2381]                [BLOCKED — connLock(X) held]
+  → writeTBQueue subQ [2386]
+  [BLOCKED — subQ full]
+```
+
+**Scenario 3**: Synchronous `ackMessage'` API (same mechanism as Scenario 2 but from external API caller)
+
+```
+ackMessage' caller:                 agentSubscriber (sole subQ reader):
+  withConnLock(X) [2254]              → sendMessagesB_ → withConnLocks({..X..})
+  → ack → ackQueueMessage [2267]      [BLOCKED — connLock(X) held]
+  → sendMsgNtf [2381]
+  → writeTBQueue subQ [2386]
+  [BLOCKED — subQ full]
+```
+
+### ConnId overlap verified
+
+No guard prevents a connection undergoing queue rotation (AM_QTEST_) or ACK processing from being included in `sendMessagesB_`'s batch. During these operations, the connection has `connStatus == ConnReady`, passing all filters in `memberSendAction`.
+
+### Cascade amplification
+
+Once any single deadlock triggers, `subQ` never drains. ALL other threads that attempt `writeTBQueue subQ` block progressively — their locks are held forever too. The entire threading system freezes within seconds.
+
+### Affected code sites (blocking `writeTBQueue subQ` inside `connLock`)
+
+| Site | File | Lock line | Write line | Events written |
+|------|------|-----------|------------|----------------|
+| `runSmpQueueMsgDelivery::notify` | Agent.hs | 2187 | 2238 | SWITCH SPCompleted, ERR INTERNAL |
+| `runSmpQueueMsgDelivery::internalErr/notifyDel` | Agent.hs | 2187 | 2238 (via notifyDel→notify) | ERR INTERNAL + delMsg |
+| `ackQueueMessage::sendMsgNtf` | Agent.hs | 2254 or 1930 | 2386 | MSGNTF |
+
+### Safe patterns that already exist in the codebase
+
+1. **`isFullTBQueue` + pending TVar** (used at `runCommandProcessing` lines 1782-1784/1937, and `runProcessSMP` lines 3027-3029/3216):
+   ```haskell
+   -- Before processing (e.g. line 1782):
+   pending <- newTVarIO []
+   -- During processing — safe notify (e.g. line 1937):
+   notify cmd =
+     let t = (corrId, connId, AEvt (sAEntity @e) cmd)
+      in atomically $ ifM (isFullTBQueue subQ) (modifyTVar' pendingCmds (t :)) (writeTBQueue subQ t)
+   -- After processing — flush (e.g. line 1784):
+   mapM_ (atomically . writeTBQueue subQ) . reverse =<< readTVarIO pending
+   ```
+
+2. **`nonBlockingWriteTBQueue`** (used at Client.hs:789, NtfSubSupervisor.hs:507):
+   ```haskell
+   nonBlockingWriteTBQueue q x = do
+     sent <- atomically $ tryWriteTBQueue q x
+     unless sent $ void $ forkIO $ atomically $ writeTBQueue q x
+   ```
+   Note: `nonBlockingWriteTBQueue` does NOT preserve ordering — the spawned background thread may complete out of order relative to subsequent direct writes from the same calling thread.
+
+### Exhaustive proof: no other deadlock scenarios exist
+
+All 15 `withConnLock` sites in Agent.hs were analyzed. Only 3 write to `subQ`:
+
+| withConnLock site | Writes subQ? | Safe? |
+|-------------------|-------------|-------|
+| switchConnectionAsync' (899) | No | ✓ |
+| setConnShortLinkAsync' (995) | No | ✓ |
+| setConnShortLink' (1031) | No | ✓ |
+| deleteConnShortLink' (1075) | No | ✓ |
+| allowConnection' (1407) | No | ✓ |
+| acceptContact' (1417) | No | ✓ |
+| sendMessagesB_ (1708, `withConnLocks`) | No | ✓ |
+| tryWithLock/runSmpCommand (1930) | Yes (1937) | ✓ — `isFullTBQueue` check |
+| tryMoveableWithLock/runSmpCommand (1931) | Yes (1937) | ✓ — `isFullTBQueue` check |
+| **runSmpQueueMsgDelivery AM_QTEST_ (2187)** | **Yes (2238)** | **✗ — DEADLOCK** |
+| **ackMessage' (2254)** | **Yes (2386)** | **✗ — DEADLOCK** |
+| switchConnection' (2298) | No | ✓ |
+| abortConnectionSwitch' (2328) | No | ✓ |
+| synchronizeRatchet' (2351) | No | ✓ |
+| suspendConnection' (2390) | No | ✓ |
+| **processSMP (3037)** | Yes (3216) | ✓ — `isFullTBQueue` check |
+
+Note: `processSMP` (line 3037) holds `connLock` and its local `notify` (line 3216) writes to `subQ`, but it uses the safe `isFullTBQueue` pattern. Its `ack` (line 3196) uses `enqueueCmd` (DB-only), NOT `ackQueueMessage`. The actual `ackQueueMessage` runs later from the async command worker via ICAck/ICAckDel.
+
+Other lock pairs checked — no circular dependencies:
+- `connLock × DB MVar`: DB never acquires connLock
+- `entityLock × connLock`: consistent ordering (entity first in chat, conn in agent)
+- `connLock(X) × connLock(Y)`: single agentSubscriber thread, one `withConnLocks` at a time
+
+---
+
+## Deadlock call graph: agentSubscriber → connLock
+
+All deadlock paths require `agentSubscriber` to synchronously acquire `connLock`. Exhaustive analysis shows that **every such path converges on a single agent function**: `sendMessagesB_` → `withConnLocks` (Agent.hs:1708). No other agent API function called synchronously from the agentSubscriber acquires connLock.
+
+Verified (FACT): `ackMessageAsync` → `enqueueCommand` only (no connLock). `toggleConnectionNtfs` → no lock. `deleteConnectionAsync` → `deleteLock` not `connLock`. `joinConnectionAsync` → `withInvLock` not `connLock`.
+
+Also verified (FACT): `Lock = TMVar Text` (Lock.hs:24) is **non-reentrant** — double acquisition on the same thread deadlocks.
+
+### All 22 trigger paths
+
+Every path goes through `deliverMessage`/`deliverMessages`/`deliverMessagesB` → `withAgent sendMessagesB` → `sendMessagesB_` → `withConnLocks`:
+
+| # | Trigger | Chat function | ConnIds locked | Risk |
+|---|---------|--------------|----------------|------|
+| 1 | Group CON (Invitee) | `introduceToAll` → broadcast XGrpMemNew | **ALL member connIds** | **HIGHEST** |
+| 2 | Group MSG XGrpLinkAcpt | `introduceToRemaining` → broadcast | **ALL member connIds** | **HIGHEST** |
+| 3 | Group CON (Invitee) | `sendIntroductions` → batch intros to new member | new member connId | Medium |
+| 4 | Group CON (Invitee) | `sendHistory` → batch to new member | new member connId | Medium |
+| 5 | Group CON | `sendPendingGroupMessages` | member connId | Medium |
+| 6 | Group SENT | `sendPendingGroupMessages` | member connId | Medium |
+| 7 | Group QCONT | `sendPendingGroupMessages` | member connId | Medium |
+| 8 | Group CON (PendingReview) | `introduceToModerators` → to moderators | moderator connIds | Medium |
+| 9 | Group CON (PreMember) | `sendXGrpMemCon` → to host | host connId | Low |
+| 10 | Group CON (PreMember) | `probeMatchingMemberContact` → probes + hashes | member + N matching connIds | Medium |
+| 11 | Direct CON | `probeMatchingMembers` → probes + hashes | contact + N matching connIds | Medium |
+| 12 | Direct JOINED | `sendAutoReply` | contact connId | Low |
+| 13 | Group JOINED | `sendGroupAutoReply` | member connId | Low |
+| 14 | Group INV | `sendXGrpMemInv` → to host | host connId | Low |
+| 15 | Group INV (legacy) | `sendGrpInvitation` → to contact | contact connId | Low |
+| 16 | Group MSG XGrpMemInv | `xGrpMemInv` → `sendGroupMemberMessage` | re-member connId | Low |
+| 17 | Group MSG XGrpMemDel | `forwardToMember` | deleted member connId | Low |
+| 18 | Group MSG XGrpLinkMem | `probeMatchingMemberContact` | member + N matching connIds | Medium |
+| 19 | Group MSG (dup relay) | `saveGroupRcvMsg` error → `sendDirectMemberMessage` | forwarder connId | Low |
+| 20 | SFDONE | `sendFileDescriptions` → to recipients | recipient connIds | Medium |
+| 21 | Group MSG XGrpLinkAcpt | `sendHistory` → to accepted member | accepted member connId | Medium |
+| 22 | Direct MSG (autoAccept) | `autoAcceptFile` → inline accept reply | contact connId | Low (test-only config) |
+
+### Key observations
+
+1. **Single bottleneck**: All 22 paths converge on `sendMessagesB_` → `withConnLocks` (Agent.hs:1708). The deadlock is between this lock acquisition and any worker thread holding `connLock` + blocking on `writeTBQueue subQ`.
+
+2. **Highest-risk paths** (#1, #2): Broadcasting to ALL group members in `introduceToAll` / `introduceToRemaining` acquires `withConnLocks` on ALL member connIds in a single batch. For large groups, this holds the agentSubscriber thread for a long time, during which subQ fills, which causes worker threads holding connLock on any of those connIds to deadlock.
+
+3. **Medium-risk paths** (#5-7): `sendPendingGroupMessages` fires on every CON/SENT/QCONT. These are frequent and lock the member's connId, which is the SAME connId that a delivery worker or ACK worker may hold while writing to subQ.
+
+---
+
+## Analysis: `withConnLocks` in `sendMessagesB_`
+
+### FACT: the lock protects ratchet encryption state
+
+`sendMessagesB_` (Agent.hs:1708-1713) acquires `withConnLocks` and executes:
+
+1. **`getConn_`** — reads connection metadata, send queues from DB
+2. **`setConnPQSupport`** — updates PQ encryption flag per connection
+3. **`enqueueMessagesB`** → `enqueueMessageB` → `storeSentMsg_` which calls:
+   - **`updateSndIds`** (AgentStore.hs:899) — increments `internalSndId` (sequential send counter)
+   - **`agentRatchetEncryptHeader`** (Agent.hs:3698) — reads current ratchet via `getRatchetForUpdate`, encrypts message header via `rcEncryptHeader`, writes advanced ratchet state via `updateRatchet`
+   - **`createSndMsg`** + **`createSndMsgDelivery`** — inserts message and delivery records
+
+All operations run within `unsafeWithStore` → `withTransaction` (single DB transaction per batch).
+
+### FACT: the lock CANNOT be removed
+
+Without `withConnLocks`, concurrent `sendMessagesB_` calls targeting the same connection would:
+- Read the same ratchet state, both encrypt, one overwrite the other → **ratchet desync** (unrecoverable)
+- Get duplicate `internalSndId` values → **message ID collision**
+- Race on `setConnPQSupport` → **PQ state inconsistency**
+
+The lock serializes ALL operations on the connection's encryption state. Removing it would introduce data corruption.
+
+Note: `sendMessage` (singular, line 530) uses the same `sendMessagesB_` function — there is no lock-free send path.
+
+### Eliminated strategies
+
+- **Strategy C (remove lock)**: The lock protects ratchet encryption. Removing it causes unrecoverable ratchet desync. Eliminated.
+- **Strategy A (async dispatch)**: All 22 chat-layer callers use `deliverMessagesB` return values (delivery IDs, PQ state) synchronously. `forkIO` loses results. Eliminated.
+- **Strategy W (isFullTBQueue + pending TVar)**: The existing pattern (lines 1937, 3216) buffers events in a local TVar and flushes after lock release. Between lock release and flush, another thread can acquire the same connLock and write events to subQ — reordering events within the same connection. This trades a visible deadlock for invisible ordering bugs. Eliminated.
+- **Strategy O (per-connection overflow queues)**: Bounded overflow queues with "drop when full" were analyzed. Drop consequences are unacceptable at 5 of 6 write sites — CONF, INFO, CON cause permanent connection failure after ACK; INV loses connection invitations; SENT/MERR leave messages stuck forever. Unbounded overflow defeats backpressure. Eliminated.
+
+---
+
+## Solution: move subQ writes outside connLock
+
+### Root cause
+
+The `writeTBQueue subQ` calls at the 3 deadlock sites are inside `connLock` by accident of code structure, not necessity. `connLock` protects ratchet encryption state and DB consistency. The `notify` calls write informational events to `subQ` — they do not modify any state that `connLock` protects.
+
+Moving the writes outside the lock scope eliminates the deadlock: blocking `writeTBQueue subQ` without holding `connLock` is safe — agentSubscriber is free to acquire the lock, process events, and drain `subQ`.
+
+### Why reordering doesn't matter at these sites
+
+The chat layer handlers for the 3 deadlock site events do NOT advance the ratchet:
+
+| Event | Chat handler | Calls sendMessagesB_? |
+|-------|-------------|----------------------|
+| SWITCH SPCompleted | Creates internal chat item, updates UI | **No** |
+| ERR INTERNAL | Logs error to view | **No** |
+| MSGNTF | `toView CEvtNtfMessage` → empty output | **No** |
+
+Events that DO trigger ratchet advances (CON, SENT, QCONT → `sendPendingGroupMessages` → `sendMessagesB_`) are all already written OUTSIDE `connLock` in the current code.
+
+Ratchet state lives in the DB, not in subQ events. agentSubscriber processes events sequentially regardless of arrival order. The SENT-before-SWITCH race already exists in the current code (new queue worker writes SENT outside connLock while old queue worker writes SWITCH inside connLock).
+
+### Fix: Site 1 — `runSmpQueueMsgDelivery` AM_QTEST_ (line 2187)
+
+Restructure `withConnLock` to return the event, write outside.
+
+**Current code** (Agent.hs:2187-2214):
+```haskell
+AM_QTEST_ -> withConnLock c connId "runSmpQueueMsgDelivery AM_QTEST_" $ do
+  withStore' c $ \db -> setSndQueueStatus db sq Active
+  SomeConn _ conn <- withStore c (`getConn` connId)
+  case conn of
+    DuplexConnection cData' rqs sqs -> do
+      let addr = qAddress sq
+      case findQ addr sqs of
+        Just SndQueue {dbReplaceQueueId = Just replacedId, primary} ->
+          case removeQP (\sq' -> dbQId sq' == replacedId && not (sameQueue addr sq')) sqs of
+            Nothing -> internalErr msgId "sent QTEST: queue not found in connection"
+            Just (sq', sq'' : sqs') -> do
+              checkSQSwchStatus sq' SSSendingQTEST
+              atomically $ TM.delete (qAddress sq') $ smpDeliveryWorkers c
+              withStore' c $ \db -> do
+                when primary $ setSndQueuePrimary db connId sq
+                deletePendingMsgs db connId sq'
+                deleteConnSndQueue db connId sq'
+              let sqs'' = sq'' :| sqs'
+                  conn' = DuplexConnection cData' rqs sqs''
+              cStats <- connectionStats c conn'
+              notify $ SWITCH QDSnd SPCompleted cStats       -- DEADLOCK
+            _ -> internalErr msgId "sent QTEST: ..."         -- DEADLOCK (via notifyDel → notify)
+        _ -> internalErr msgId "sent QTEST: ..."             -- DEADLOCK
+    _ -> internalErr msgId "QTEST sent not in duplex ..."    -- DEADLOCK
+```
+
+**New code:**
+```haskell
+AM_QTEST_ -> do
+  evt_ <- withConnLock c connId "runSmpQueueMsgDelivery AM_QTEST_" $ do
+    withStore' c $ \db -> setSndQueueStatus db sq Active
+    SomeConn _ conn <- withStore c (`getConn` connId)
+    case conn of
+      DuplexConnection cData' rqs sqs -> do
+        let addr = qAddress sq
+        case findQ addr sqs of
+          Just SndQueue {dbReplaceQueueId = Just replacedId, primary} ->
+            case removeQP (\sq' -> dbQId sq' == replacedId && not (sameQueue addr sq')) sqs of
+              Nothing -> pure $ Left "sent QTEST: queue not found in connection"
+              Just (sq', sq'' : sqs') -> do
+                checkSQSwchStatus sq' SSSendingQTEST
+                atomically $ TM.delete (qAddress sq') $ smpDeliveryWorkers c
+                withStore' c $ \db -> do
+                  when primary $ setSndQueuePrimary db connId sq
+                  deletePendingMsgs db connId sq'
+                  deleteConnSndQueue db connId sq'
+                let sqs'' = sq'' :| sqs'
+                    conn' = DuplexConnection cData' rqs sqs''
+                cStats <- connectionStats c conn'
+                pure $ Right $ SWITCH QDSnd SPCompleted cStats
+              _ -> pure $ Left "sent QTEST: there is only one queue in connection"
+          _ -> pure $ Left "sent QTEST: queue not in connection or not replacing another queue"
+      _ -> pure $ Left "QTEST sent not in duplex connection"
+  -- subQ write is now OUTSIDE connLock — blocking writeTBQueue is safe
+  case evt_ of
+    Right evt -> notify evt
+    Left err -> internalErr msgId err
+```
+
+All DB operations remain inside the lock. Only `notify`/`internalErr` (which write to subQ) move outside. `internalErr` calls `notifyDel` = `notify >> delMsg` — both `notify` (subQ write) and `delMsg` (`deleteSndMsgDelivery`, keyed on unique msgId) are safe outside the lock. The existing double-delete pattern (`delMsg` inside `internalErr` + `delMsgKeep` at line 2216) is preserved.
+
+### Fix: Sites 2 & 3 — `ackQueueMessage::sendMsgNtf` (line 2386)
+
+Change `ackQueueMessage` to return the MSGNTF event instead of writing it to subQ. Callers write to subQ after releasing connLock.
+
+**Current code** (Agent.hs:2371-2386):
+```haskell
+ackQueueMessage :: AgentClient -> RcvQueue -> SMP.MsgId -> AM ()
+ackQueueMessage c rq@RcvQueue {userId, connId, server} srvMsgId = do
+  atomically $ incSMPServerStat c userId server ackAttempts
+  tryAllErrors (sendAck c rq srvMsgId) >>= \case
+    Right _ -> sendMsgNtf ackMsgs
+    Left (SMP _ SMP.NO_MSG) -> sendMsgNtf ackNoMsgErrs
+    Left e -> ...
+  where
+    sendMsgNtf stat = do
+      atomically $ incSMPServerStat c userId server stat
+      whenM (liftIO $ hasGetLock c rq) $ do
+        atomically $ releaseGetLock c rq
+        brokerTs_ <- eitherToMaybe <$> tryAllErrors (withStore c $ \db -> getRcvMsgBrokerTs db connId srvMsgId)
+        atomically $ writeTBQueue (subQ c) ("", connId, AEvt SAEConn $ MSGNTF srvMsgId brokerTs_)
+```
+
+**New code** — return `Maybe ATransmission` instead of writing:
+```haskell
+ackQueueMessage :: AgentClient -> RcvQueue -> SMP.MsgId -> AM (Maybe ATransmission)
+ackQueueMessage c rq@RcvQueue {userId, connId, server} srvMsgId = do
+  atomically $ incSMPServerStat c userId server ackAttempts
+  tryAllErrors (sendAck c rq srvMsgId) >>= \case
+    Right _ -> sendMsgNtf ackMsgs
+    Left (SMP _ SMP.NO_MSG) -> sendMsgNtf ackNoMsgErrs
+    Left e -> ... >> pure Nothing
+  where
+    sendMsgNtf stat = do
+      atomically $ incSMPServerStat c userId server stat
+      ifM (liftIO $ hasGetLock c rq)
+        (do atomically $ releaseGetLock c rq
+            brokerTs_ <- eitherToMaybe <$> tryAllErrors (withStore c $ \db -> getRcvMsgBrokerTs db connId srvMsgId)
+            pure $ Just ("", connId, AEvt SAEConn $ MSGNTF srvMsgId brokerTs_))
+        (pure Nothing)
+```
+
+**Caller 1: `ackMessage'`** (Agent.hs:2253-2267) — return event from `withConnLock`, write after:
+```haskell
+ackMessage' c connId msgId rcptInfo_ = do
+  t_ <- withConnLock c connId "ackMessage" $ do
+    SomeConn _ conn <- withStore c (`getConn` connId)
+    case conn of
+      DuplexConnection {} -> do
+        t_ <- ack
+        sendRcpt conn
+        del
+        pure t_
+      RcvConnection {} -> do
+        t_ <- ack
+        del
+        pure t_
+      SndConnection {} -> throwE $ CONN SIMPLEX "ackMessage"
+      ContactConnection {} -> throwE $ CMD PROHIBITED "ackMessage: ContactConnection"
+      NewConnection _ -> throwE $ CMD PROHIBITED "ackMessage: NewConnection"
+  -- subQ write is OUTSIDE connLock
+  case t_ of
+    Just t -> atomically $ writeTBQueue (subQ c) t
+    Nothing -> pure ()
+```
+
+**Caller 2: `ICAck` / `ICAckDel`** (Agent.hs:1823-1824) — inline `tryWithLock` as `tryCommand` + `withConnLock`, write subQ between the two scopes:
+
+`tryWithLock name = tryCommand . withConnLock c connId name` — by inlining, the subQ write can be placed outside `withConnLock` but inside `tryCommand` (retaining retry/error handling).
+
+```haskell
+ICAck rId srvMsgId -> withServer $ \srv ->
+  tryCommand $ do
+    t_ <- withConnLock c connId "ICAck" $ ack srv rId srvMsgId
+    -- subQ write is OUTSIDE connLock — cannot deadlock with agentSubscriber
+    forM_ t_ $ atomically . writeTBQueue subQ
+
+ICAckDel rId srvMsgId msgId -> withServer $ \srv ->
+  tryCommand $ do
+    t_ <- withConnLock c connId "ICAckDel" $ do
+      t_ <- ack srv rId srvMsgId
+      withStore' c (\db -> deleteMsg db connId msgId)
+      pure t_
+    -- subQ write is OUTSIDE connLock — cannot deadlock with agentSubscriber
+    forM_ t_ $ atomically . writeTBQueue subQ
+```
+
+Where `ack` now returns `AM (Maybe ATransmission)`:
+```haskell
+ack srv rId srvMsgId = do
+  rq <- withStore c $ \db -> getRcvQueue db connId srv rId
+  ackQueueMessage c rq srvMsgId
+```
+
+All subQ writes for MSGNTF are now outside connLock. FIFO ordering is preserved — no `nonBlockingWriteTBQueue`, no forked threads. The same thread that held the lock writes to subQ sequentially after releasing it.
+
+### Race analysis
+
+Window between connLock release and subQ write at Site 1:
+
+| Thread | Can acquire connLock(X)? | Writes subQ? | Consequence |
+|--------|-------------------------|-------------|-------------|
+| agentSubscriber via sendMessagesB_ | Yes | **No** (encrypts only) | No race |
+| processSMP for connId X | Yes | Yes (pending flush) | MSG before SWITCH — cosmetic |
+| runCommandProcessing for connId X | Yes | Yes (pending flush) | Command response before SWITCH — cosmetic |
+| New queue delivery worker | No (SENT outside lock) | Yes | SENT before SWITCH — cosmetic, **already exists in current code** |
+
+All races are cosmetic UI ordering. None affect ratchet state, protocol correctness, or message delivery.
+
+### Summary of changes
+
+| File | Change | Lines affected |
+|------|--------|---------------|
+| Agent.hs | Restructure AM_QTEST_ to return event from `withConnLock`, write outside | ~2187-2214 |
+| Agent.hs | Change `ackQueueMessage` return type to `AM (Maybe ATransmission)`, return event instead of writing | ~2371-2386 |
+| Agent.hs | `ackMessage'`: return event from `withConnLock`, write outside | ~2253-2267 |
+| Agent.hs | `ICAck`/`ICAckDel`: inline `tryCommand` + `withConnLock`, write subQ between scopes | ~1823-1824 |
+| Agent.hs | `ack` helper: propagate new return type | ~1899-1901 |
+
+No new data structures. No new modules. No changes to other write sites (1937, 3216 — already safe). ~25 lines changed total.

rfcs/README.md

@@ -0,0 +1,150 @@
+# SimpleX Network Protocol Specifications — Governance and Evolution (draft)
+
+## Why this document exists
+
+SimpleX Network protocol specifications must evolve as the network grows. This document defines how specifications change, who governs those changes, and how the history of changes is preserved.
+
+### Lessons from the web: why ratcheted governance matters
+
+The web's governance history demonstrates both the necessity of consortium governance and the dangers of getting the transition wrong.
+
+[Tim Berners-Lee invented the web in 1991](https://home.cern/science/computing/birth-web/short-history-web). [Netscape took over in 1994](https://en.wikipedia.org/wiki/Netscape_Navigator), driving rapid innovation as a single company — SSL, cookies, JavaScript, and the features that made the web commercially viable. In 1994, [W3C was founded](https://www.w3.org/about/history/) as a consortium hosted across multiple independent institutions (MIT in the US, INRIA/ERCIM in Europe, Keio University in Japan, later Beihang University in China) to govern web standards.
+
+The transition from company-led innovation to consortium governance was abrupt rather than gradual. Netscape's decline (accelerated by the [browser wars](https://en.wikipedia.org/wiki/Browser_wars) and [AOL acquisition](https://cybercultural.com/p/1999-the-fall-of-netscape-and-the-rise-of-mozilla/)) transferred control to a standards body that prioritized process over progress. The result was [a lost decade of web stagnation](https://eev.ee/blog/2020/02/01/old-css-new-css/): CSS 2.0 shipped in 1998; CSS 2.1 didn't reach Candidate Recommendation until 2004 and wasn't finalized until 2011. W3C pursued XHTML and rejected proposed enhancements to HTML, until frustrated engineers from Apple, Mozilla, and Opera formed [WHATWG in 2004](https://en.wikipedia.org/wiki/WHATWG) to build HTML5 outside W3C's process. The abrupt governance transition, without a mechanism to balance community guarantees against the imperative to continue evolving the product at pace, dramatically slowed web evolution at the time it was needed most.
+
+Then in 2023, [W3C restructured from a multi-host consortium into a single 501(c)(3) nonprofit entity](https://www.w3.org/press-releases/2023/w3c-le-launched/) — W3C Inc, incorporated in the US. The previous structure distributed governance across four independent university hosts in different countries, making capture by any single entity structurally difficult. The new structure concentrates governance in a single legal entity with a board of directors. While presented as modernization, this effectively ended the decentralized consortium model that had protected web standards for nearly three decades.
+
+### The governance double ratchet
+
+SimpleX follows the same Netscape-to-consortium evolution path, but with two ratchets designed to prevent both failure modes — stagnation from premature governance transfer, and capture from governance centralization:
+
+- **Licensing ratchet**: all contributed IP is licensed under AGPLv3 (software) and Creative Commons (documentation), perpetually and irrevocably. What is licensed cannot be unlicensed. If a Party transfers Licensed IP, the licensing obligations transfer with it.
+
+- **Governance ratchet**: power can be given to the SimpleX Network Consortium, but never taken back. The Consortium Agreement requires majority decision of all Governing Parties for changes to the agreement itself, IP policy, and admission or removal of parties.
+
+The ratcheted transition is historically proven to be necessary. It allows the company to continue driving rapid product innovation (as Netscape did for the web) while incrementally and irreversibly transferring governance to the consortium, without the abrupt handover that stalled web evolution or the centralization that later undermined it.
+
+### Specification governance via the Consortium Agreement
+
+The SimpleX Network Consortium Agreement (being deployed in 2026) establishes two levels of intellectual property governance: **Licensed IP** (all contributed protocol specifications, software, and documentation, licensed perpetually and irrevocably) and **Core IP** (the subset essential to the network, requiring consortium governance to change). The distinction between these levels and how they map to the RFC process is described in [Standard vs Core specifications](#standard-vs-core-specifications) below.
+
+## Specification change process: protocol specifications and RFCs
+
+Protocol knowledge lives in two places:
+
+### `protocol/` — Consolidated specifications
+
+Each file is a complete, self-contained description of a protocol as it exists today. Like consolidated legislation in the UK legal system: the full current law in one document, not a patchwork of amendments.
+
+Consolidated specifications are maintained on every code change that affects protocol behavior. With LLMs, the cost of maintaining consolidated documents collapses — reworking prose to incorporate a new RFC is now inexpensive relative to the value of a single authoritative document per protocol.
+
+Implementers read `protocol/`. They should never need to reconstruct current behavior from a base spec plus a chain of RFCs.
+
+### `rfcs/` — Protocol evolution commits
+
+Each RFC describes a single change to a protocol specification. RFCs are the atomic unit of protocol evolution — analogous to commits in version control, or amending acts in legislation.
+
+An RFC is not part of the protocol specification. It becomes part of the specification only when embedded into the consolidated `protocol/` document. The RFC itself remains as a permanent historical record of what changed, when, and why.
+
+## RFC lifecycle
+
+```
+                  ┌——> done/ ——> standard/
+draft (root) ——>──┤
+                  └——> rejected/
+```
+
+### Draft — `rfcs/*.md`
+
+A proposal for a protocol change. Not yet implemented. Active proposals live in the `rfcs/` root directory.
+
+Named by proposal date: `YYYY-MM-DD-topic.md`.
+
+A draft may be rejected if the proposal is considered but not accepted for implementation.
+
+### Done — `rfcs/done/`
+
+Implemented in code. The protocol change described by this RFC exists in the codebase, but the RFC has not yet been verified against the actual implementation (code may have diverged from the proposal during implementation).
+
+### Standard — `rfcs/standard/`
+
+Verified against the actual implementation and synchronized with code. The RFC accurately describes what was implemented. This is a permanent historical record — standard RFCs are never modified or removed.
+
+On promotion to standard, the RFC is:
+1. Renamed from proposal date to standardization date: `YYYY-MM-DD-topic.md` (new date, same topic slug)
+2. Updated with a document history header capturing the full lifecycle
+3. Embedded into the corresponding `protocol/` consolidated specification
+
+The `protocol/` document references embedded RFCs by name (e.g., "Private message routing added by RFC 2023-09-12-second-relays, standardized 2026-XX-XX"), similar to UK legislation citing the amending act for each clause.
+
+Protocol version numbers make it clear which RFCs are included in which protocol revision — no separate tracking is needed.
+
+### Rejected — `rfcs/rejected/`
+
+Draft proposals that were considered but not accepted for implementation. Only drafts move to rejected — once an RFC is implemented (done/), it proceeds to standard/ after verification. Preserved for historical record of design decisions.
+
+### Document history header
+
+Every RFC in `standard/` carries a history header:
+
+```
+---
+Proposed: YYYY-MM-DD
+Implemented: YYYY-MM-DD
+Standardized: YYYY-MM-DD
+Protocol: simplex-messaging v9 (or whichever protocol this amends)
+---
+```
+
+## Governance
+
+SimpleX Network follows the Netscape-to-W3C evolution path, with ratcheted rather than abrupt transitions:
+
+| Phase | Period | Governance | Development process |
+|-------|--------|-----------|-------------------|
+| Protocol invented | 2020 | Two people | Prototype developed |
+| SimpleX Chat Ltd | 2022 | One company | Product-first: code leads, specs follow |
+| SimpleX Network Consortium | 2026 | Agreement of SimpleX Chat Ltd and non-profit entities | Product-first for standard; standards-first for core |
+| Decentralized governance | Future | TBD (DAO research ongoing) | Standards-first |
+
+### Current: product-first development
+
+SimpleX protocols currently follow a product-first development process: requirements drive code, code drives specification. RFCs are written as design proposals before implementation, but implementation details are figured out in code. Consolidated protocol specifications in `protocol/` are then amended to match the implementation.
+
+This process is governed by SimpleX Chat Ltd as the IP Holding Party under the Consortium Agreement.
+
+Any Specification Author (as defined in the Consortium Agreement) may propose RFCs. Acceptance and standardization decisions are made by SimpleX Chat Ltd during the current product-first phase.
+
+### Standard vs Core specifications
+
+The distinction between standard and core maps directly to the two levels of IP governance in the Consortium Agreement, and reflects the difference between product-first and standards-first development:
+
+**Standard** — Licensed IP, not yet under consortium governance. Governed by the company.
+
+All contributed protocol specifications are Licensed IP under the Consortium Agreement. Standard specifications follow product-first development: the company can evolve them with product needs, and they must be maintained on every code change that affects protocol behavior.
+
+Standard specifications live in `rfcs/standard/` and `protocol/`.
+
+**Core** — Governed IP, governed by the consortium.
+
+A subset of standard specifications will be designated as Core IP under the Consortium Agreement. Core specifications will follow standards-first development: specification changes must be agreed via Governing Decision before code changes.
+
+This is a legally binding commitment. Once Licensed IP is included in Core IP, the company that owns the code cannot unilaterally change it — even though they own the code, the Consortium Agreement requires a Governing Decision for any change to Core IP. This protects the fundamental properties of the network (privacy, security, decentralization) from unilateral modification by any single party.
+
+The designation of specific specifications as Core IP is itself a Governing Decision requiring unanimous approval. The transition will happen incrementally as protocols stabilize — the governance ratchet ensures that each designation is irreversible.
+
+The exact mechanism for distinguishing core from standard within the RFC and protocol folder structure is TBD — it will be decided as the first protocols are designated as Core IP.
+
+### Future: standards-first development
+
+As more protocols are designated as Core IP, development naturally transitions to a standards-first process for a growing portion of the protocol suite. The governance ratchet ensures this transition is gradual and irreversible — each protocol that becomes core gains the protection of consortium governance permanently, while remaining standard protocols continue to evolve at product pace.
+
+## Current state
+
+| Location | Contents | Count |
+|----------|----------|-------|
+| `protocol/` | Consolidated specs (SMP v9, Agent v5, XFTP v2, XRCP v1, Push v2, PQDR v1) | 6 specs + overview |
+| `rfcs/` root | Active draft proposals | 19 |
+| `rfcs/done/` | Implemented, not yet verified | 25 |
+| `rfcs/standard/` | Verified against implementation | (to be populated) |
+| `rfcs/rejected/` | Draft proposals not accepted | 7 |

scripts/simplexmq-reproduce-builds.sh

@@ -47,7 +47,7 @@ for os in 22.04 24.04; do
 	docker exec \
 		-t \
 		builder \
-		sh -c 'cabal update && cabal build --jobs=$(nproc) --enable-tests -fserver_postgres && mkdir -p /out && for i in smp-server simplexmq-test; do bin=$(find /project/dist-newstyle -name "$i" -type f -executable) && chmod +x "$bin" && mv "$bin" /out/; done && strip /out/smp-server'
+		sh -c 'git config --global --add safe.directory \*; cabal update && cabal build --jobs=$(nproc) --enable-tests -fserver_postgres && mkdir -p /out && for i in smp-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'
 
 	# Copy smp-server postgresql binary and prepare it
 	docker cp \

simplexmq.cabal

@@ -1,7 +1,7 @@
 cabal-version: 1.12
 
 name:           simplexmq
-version:        6.4.1.0
+version:        6.5.0.9
 synopsis:       SimpleXMQ message broker
 description:    This package includes <./docs/Simplex-Messaging-Server.html server>,
                 <./docs/Simplex-Messaging-Client.html client> and
@@ -103,12 +103,13 @@ library
       Simplex.Messaging.Agent.Store.AgentStore
       Simplex.Messaging.Agent.Store.Common
       Simplex.Messaging.Agent.Store.DB
+      Simplex.Messaging.Agent.Store.Entity
       Simplex.Messaging.Agent.Store.Interface
       Simplex.Messaging.Agent.Store.Migrations
       Simplex.Messaging.Agent.Store.Migrations.App
       Simplex.Messaging.Agent.Store.Postgres.Options
       Simplex.Messaging.Agent.Store.Shared
-      Simplex.Messaging.Agent.TRcvQueues
+      Simplex.Messaging.Agent.TSessionSubs
       Simplex.Messaging.Client
       Simplex.Messaging.Client.Agent
       Simplex.Messaging.Compression
@@ -130,12 +131,13 @@ library
       Simplex.Messaging.Notifications.Types
       Simplex.Messaging.Parsers
       Simplex.Messaging.Protocol
+      Simplex.Messaging.Protocol.Types
       Simplex.Messaging.Server.Expiration
       Simplex.Messaging.Server.QueueStore.Postgres.Config
       Simplex.Messaging.Server.QueueStore.QueueInfo
       Simplex.Messaging.ServiceScheme
       Simplex.Messaging.Session
-      Simplex.Messaging.Agent.Store.Entity
+      Simplex.Messaging.SystemTime
       Simplex.Messaging.TMap
       Simplex.Messaging.Transport
       Simplex.Messaging.Transport.Buffer
@@ -163,6 +165,9 @@ library
           Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250203_msg_bodies
           Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250322_short_links
           Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250702_conn_invitations_remove_cascade_delete
+          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
   else
       exposed-modules:
           Simplex.Messaging.Agent.Store.SQLite
@@ -210,6 +215,10 @@ library
           Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250203_msg_bodies
           Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250322_short_links
           Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250702_conn_invitations_remove_cascade_delete
+          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.Util
   if flag(client_postgres) || flag(server_postgres)
       exposed-modules:
           Simplex.Messaging.Agent.Store.Postgres
@@ -224,6 +233,7 @@ library
           Simplex.FileTransfer.Server.Control
           Simplex.FileTransfer.Server.Env
           Simplex.FileTransfer.Server.Main
+          Simplex.FileTransfer.Server.Prometheus
           Simplex.FileTransfer.Server.Stats
           Simplex.FileTransfer.Server.Store
           Simplex.FileTransfer.Server.StoreLog
@@ -233,6 +243,7 @@ library
           Simplex.Messaging.Server.Env.STM
           Simplex.Messaging.Server.Information
           Simplex.Messaging.Server.Main
+          Simplex.Messaging.Server.Main.GitCommit
           Simplex.Messaging.Server.Main.Init
           Simplex.Messaging.Server.MsgStore
           Simplex.Messaging.Server.MsgStore.Journal
@@ -264,6 +275,7 @@ library
               Simplex.Messaging.Notifications.Server.Store.Postgres
               Simplex.Messaging.Notifications.Server.Store.Types
               Simplex.Messaging.Notifications.Server.StoreLog
+              Simplex.Messaging.Server.MsgStore.Postgres
               Simplex.Messaging.Server.QueueStore.Postgres
               Simplex.Messaging.Server.QueueStore.Postgres.Migrations
   other-modules:
@@ -335,6 +347,7 @@ library
       , process ==1.6.*
       , temporary ==1.3.*
       , websockets ==0.12.*
+      , zlib >=0.6 && <0.8
   if flag(client_postgres) || flag(server_postgres)
     build-depends:
         postgresql-libpq >=0.10.0.0
@@ -353,10 +366,12 @@ library
   if impl(ghc >= 9.6.2)
     build-depends:
         bytestring ==0.11.*
+      , template-haskell ==2.20.*
       , text >=2.0.1 && <2.2
   if impl(ghc < 9.6.2)
     build-depends:
         bytestring ==0.10.*
+      , template-haskell ==2.16.*
       , text >=1.2.3.0 && <1.3
 
 executable ntf-server
@@ -469,7 +484,7 @@ test-suite simplexmq-test
       CoreTests.RetryIntervalTests
       CoreTests.SOCKSSettings
       CoreTests.StoreLogTests
-      CoreTests.TRcvQueuesTests
+      CoreTests.TSessionSubs
       CoreTests.UtilTests
       CoreTests.VersionRangeTests
       FileDescriptionTests
@@ -483,6 +498,7 @@ test-suite simplexmq-test
       XFTPCLI
       XFTPClient
       XFTPServerTests
+      XFTPWebTests
       Static
       Static.Embedded
       Paths_simplexmq
@@ -512,6 +528,7 @@ test-suite simplexmq-test
     , async
     , base64-bytestring
     , bytestring
+    , case-insensitive ==1.2.*
     , containers
     , crypton
     , crypton-x509

src/Simplex/FileTransfer/Agent.hs

@@ -47,7 +47,7 @@ import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as M
 import Data.Maybe (fromMaybe, mapMaybe)
 import qualified Data.Set as S
-import Data.Text (Text)
+import Data.Text (Text, pack)
 import Data.Time.Clock (getCurrentTime)
 import Data.Time.Format (defaultTimeLocale, formatTime)
 import Simplex.FileTransfer.Chunks (toKB)
@@ -75,7 +75,7 @@ import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String (strDecode, strEncode)
 import Simplex.Messaging.Protocol (ProtocolServer, ProtocolType (..), XFTPServer)
 import qualified Simplex.Messaging.TMap as TM
-import Simplex.Messaging.Util (catchAll_, liftError, tshow, unlessM, whenM)
+import Simplex.Messaging.Util (allFinally, catchAll_, catchAllErrors, liftError, tshow, unlessM, whenM)
 import System.FilePath (takeFileName, (</>))
 import UnliftIO
 import UnliftIO.Directory
@@ -198,10 +198,10 @@ runXFTPRcvWorker c srv Worker {doWork} = do
             liftIO $ waitForUserNetwork c
             atomically $ incXFTPServerStat c userId srv downloadAttempts
             downloadFileChunk fc replica approvedRelays
-              `catchAgentError` \e -> retryOnError "XFTP rcv worker" (retryLoop loop e delay') (retryDone e) e
+              `catchAllErrors` \e -> retryOnError "XFTP rcv worker" (retryLoop loop e delay') (retryDone e) e
           where
             retryLoop loop e replicaDelay = do
-              flip catchAgentError (\_ -> pure ()) $ do
+              flip catchAllErrors (\_ -> pure ()) $ do
                 when (serverHostError e) $ notify c (fromMaybe rcvFileEntityId redirectEntityId_) (RFWARN e)
                 liftIO $ closeXFTPServerClient c userId server digest
                 withStore' c $ \db -> updateRcvChunkReplicaDelay db rcvChunkReplicaId replicaDelay
@@ -223,6 +223,7 @@ runXFTPRcvWorker c srv Worker {doWork} = do
       agentXFTPDownloadChunk c userId digest replica chunkSpec
       liftIO $ waitUntilForeground c
       (entityId, complete, progress) <- withStore c $ \db -> runExceptT $ do
+        liftIO $ lockRcvFileForUpdate db rcvFileId
         liftIO $ updateRcvFileChunkReceived db (rcvChunkReplicaId replica) rcvChunkId relChunkPath
         RcvFile {size = FileSize currentSize, chunks, redirect} <- ExceptT $ getRcvFile db rcvFileId
         let rcvd = receivedSize chunks
@@ -280,7 +281,7 @@ runXFTPRcvLocalWorker c Worker {doWork} = do
     runXFTPOperation AgentConfig {rcvFilesTTL} =
       withWork c doWork (`getNextRcvFileToDecrypt` rcvFilesTTL) $
         \f@RcvFile {rcvFileId, rcvFileEntityId, tmpPath, redirect} ->
-          decryptFile f `catchAgentError` rcvWorkerInternalError c rcvFileId rcvFileEntityId (redirectEntityId <$> redirect) tmpPath
+          decryptFile f `catchAllErrors` rcvWorkerInternalError c rcvFileId rcvFileEntityId (redirectEntityId <$> redirect) tmpPath
     decryptFile :: RcvFile -> AM ()
     decryptFile RcvFile {rcvFileId, rcvFileEntityId, size, digest, key, nonce, tmpPath, saveFile, status, chunks, redirect} = do
       let CryptoFile savePath cfArgs = saveFile
@@ -307,7 +308,7 @@ runXFTPRcvLocalWorker c Worker {doWork} = do
           liftIO $ waitUntilForeground c
           withStore' c (`updateRcvFileComplete` rcvFileId)
           -- proceed with redirect
-          yaml <- liftError (FILE . FILE_IO . show) (CF.readFile $ CryptoFile fsSavePath cfArgs) `agentFinally` (lift $ toFSFilePath fsSavePath >>= removePath)
+          yaml <- liftError (FILE . FILE_IO . show) (CF.readFile $ CryptoFile fsSavePath cfArgs) `allFinally` (lift $ toFSFilePath fsSavePath >>= removePath)
           next@FileDescription {chunks = nextChunks} <- case strDecode (LB.toStrict yaml) of
             -- TODO switch to another error constructor
             Left _ -> throwE . FILE $ REDIRECT "decode error"
@@ -399,7 +400,7 @@ runXFTPSndPrepareWorker c Worker {doWork} = do
     runXFTPOperation cfg@AgentConfig {sndFilesTTL} =
       withWork c doWork (`getNextSndFileToPrepare` sndFilesTTL) $
         \f@SndFile {sndFileId, sndFileEntityId, prefixPath} ->
-          prepareFile cfg f `catchAgentError` sndWorkerInternalError c sndFileId sndFileEntityId prefixPath
+          prepareFile cfg f `catchAllErrors` sndWorkerInternalError c sndFileId sndFileEntityId prefixPath
     prepareFile :: AgentConfig -> SndFile -> AM ()
     prepareFile _ SndFile {prefixPath = Nothing} =
       throwE $ INTERNAL "no prefix path"
@@ -413,6 +414,7 @@ runXFTPSndPrepareWorker c Worker {doWork} = do
             withStore' c $ \db -> updateSndFileStatus db sndFileId SFSEncrypting
             (digest, chunkSpecsDigests) <- encryptFileForUpload sndFile fsEncPath
             withStore c $ \db -> do
+              lockSndFileForUpdate db sndFileId
               updateSndFileEncrypted db sndFileId digest chunkSpecsDigests
               getSndFile db sndFileId
           else pure sndFile
@@ -431,7 +433,7 @@ runXFTPSndPrepareWorker c Worker {doWork} = do
         encryptFileForUpload :: SndFile -> FilePath -> AM (FileDigest, [(XFTPChunkSpec, FileDigest)])
         encryptFileForUpload SndFile {key, nonce, srcFile, redirect} fsEncPath = do
           let CryptoFile {filePath} = srcFile
-              fileName = takeFileName filePath
+              fileName = pack $ takeFileName filePath
           fileSize <- liftIO $ fromInteger <$> CF.getFileContentsSize srcFile
           when (fileSize > maxFileSizeHard) $ throwE $ FILE FT.SIZE
           let fileHdr = smpEncode FileHeader {fileName, fileExtra = Nothing}
@@ -468,11 +470,11 @@ runXFTPSndPrepareWorker c Worker {doWork} = do
                 liftIO $ waitForUserNetwork c
                 let triedAllSrvs = n > userSrvCount
                 createWithNextSrv triedHosts
-                  `catchAgentError` \e -> retryOnError "XFTP prepare worker" (retryLoop loop triedAllSrvs e) (throwE e) e
+                  `catchAllErrors` \e -> retryOnError "XFTP prepare worker" (retryLoop loop triedAllSrvs e) (throwE e) e
               where
                 -- we don't do closeXFTPServerClient here to not risk closing connection for concurrent chunk upload
                 retryLoop loop triedAllSrvs e = do
-                  flip catchAgentError (\_ -> pure ()) $ do
+                  flip catchAllErrors (\_ -> pure ()) $ do
                     when (triedAllSrvs && serverHostError e) $ notify c sndFileEntityId $ SFWARN e
                   liftIO $ assertAgentForeground c
                   loop
@@ -508,10 +510,10 @@ runXFTPSndWorker c srv Worker {doWork} = do
             liftIO $ waitForUserNetwork c
             atomically $ incXFTPServerStat c userId srv uploadAttempts
             uploadFileChunk cfg fc replica
-              `catchAgentError` \e -> retryOnError "XFTP snd worker" (retryLoop loop e delay') (retryDone e) e
+              `catchAllErrors` \e -> retryOnError "XFTP snd worker" (retryLoop loop e delay') (retryDone e) e
           where
             retryLoop loop e replicaDelay = do
-              flip catchAgentError (\_ -> pure ()) $ do
+              flip catchAllErrors (\_ -> pure ()) $ do
                 when (serverHostError e) $ notify c sndFileEntityId $ SFWARN e
                 liftIO $ closeXFTPServerClient c userId server digest
                 withStore' c $ \db -> updateSndChunkReplicaDelay db sndChunkReplicaId replicaDelay
@@ -530,6 +532,7 @@ runXFTPSndWorker c srv Worker {doWork} = do
       agentXFTPUploadChunk c userId chunkDigest replica' chunkSpec'
       liftIO $ waitUntilForeground c
       sf@SndFile {sndFileEntityId, prefixPath, chunks} <- withStore c $ \db -> do
+        lockSndFileForUpdate db sndFileId
         updateSndChunkReplicaStatus db sndChunkReplicaId SFRSUploaded
         getSndFile db sndFileId
       let uploaded = uploadedSize chunks
@@ -681,10 +684,10 @@ runXFTPDelWorker c srv Worker {doWork} = do
             liftIO $ waitForUserNetwork c
             atomically $ incXFTPServerStat c userId srv deleteAttempts
             deleteChunkReplica
-              `catchAgentError` \e -> retryOnError "XFTP del worker" (retryLoop loop e delay') (retryDone e) e
+              `catchAllErrors` \e -> retryOnError "XFTP del worker" (retryLoop loop e delay') (retryDone e) e
           where
             retryLoop loop e replicaDelay = do
-              flip catchAgentError (\_ -> pure ()) $ do
+              flip catchAllErrors (\_ -> pure ()) $ do
                 when (serverHostError e) $ notify c "" $ SFWARN e
                 liftIO $ closeXFTPServerClient c userId server chunkDigest
                 withStore' c $ \db -> updateDeletedSndChunkReplicaDelay db deletedSndChunkReplicaId replicaDelay

src/Simplex/FileTransfer/Chunks.hs

@@ -1,4 +1,14 @@
-module Simplex.FileTransfer.Chunks where
+module Simplex.FileTransfer.Chunks
+  ( serverChunkSizes,
+    chunkSize0,
+    chunkSize1,
+    chunkSize2,
+    chunkSize3,
+    kb,
+    toKB,
+    mb,
+    gb,
+  ) where
 
 import Data.Word (Word32)
 

src/Simplex/FileTransfer/Client.hs

@@ -9,7 +9,28 @@
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeApplications #-}
 
-module Simplex.FileTransfer.Client where
+module Simplex.FileTransfer.Client
+  ( XFTPClient (..),
+    XFTPClientConfig (..),
+    XFTPChunkSpec (..),
+    XFTPClientError,
+    defaultXFTPClientConfig,
+    getXFTPClient,
+    closeXFTPClient,
+    xftpClientServer,
+    xftpTransportHost,
+    createXFTPChunk,
+    addXFTPRecipients,
+    uploadXFTPChunk,
+    downloadXFTPChunk,
+    deleteXFTPChunk,
+    ackXFTPChunk,
+    pingXFTP,
+    singleChunkSize,
+    prepareChunkSizes,
+    prepareChunkSpecs,
+    getChunkDigest,
+  ) where
 
 import Control.Logger.Simple
 import Control.Monad
@@ -31,6 +52,7 @@ import qualified Data.X509 as X
 import qualified Data.X509.Validation as XV
 import qualified Network.HTTP.Types as N
 import qualified Network.HTTP2.Client as H
+import Network.Socket (HostName)
 import Simplex.FileTransfer.Chunks
 import Simplex.FileTransfer.Protocol
 import Simplex.FileTransfer.Transport
@@ -39,12 +61,13 @@ import Simplex.Messaging.Client
     NetworkRequestMode (..),
     ProtocolClientError (..),
     TransportSession,
-    netTimeoutInt,
     chooseTransportHost,
-    defaultNetworkConfig,
-    transportClientConfig,
     clientSocksCredentials,
+    defaultNetworkConfig,
+    netTimeoutInt,
+    transportClientConfig,
     unexpectedResponse,
+    useWebPort,
   )
 import qualified Simplex.Messaging.Crypto as C
 import qualified Simplex.Messaging.Crypto.Lazy as LC
@@ -52,10 +75,12 @@ import Simplex.Messaging.Encoding (smpDecode, smpEncode)
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol
   ( BasicAuth,
+    NetworkError (..),
     Protocol (..),
     ProtocolServer (..),
     RecipientId,
     SenderId,
+    toNetworkError,
     pattern NoEntity,
   )
 import Simplex.Messaging.Transport (ALPN, CertChainPubKey (..), HandshakeError (..), THandleAuth (..), THandleParams (..), TransportError (..), TransportPeer (..), defaultSupportedParams)
@@ -104,12 +129,13 @@ defaultXFTPClientConfig =
       clientALPN = Just alpnSupportedXFTPhandshakes
     }
 
-getXFTPClient :: TransportSession FileResponse -> XFTPClientConfig -> UTCTime -> (XFTPClient -> IO ()) -> IO (Either XFTPClientError XFTPClient)
-getXFTPClient transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN, xftpNetworkConfig, serverVRange} proxySessTs disconnected = runExceptT $ do
+getXFTPClient :: TransportSession FileResponse -> XFTPClientConfig -> [HostName] -> UTCTime -> (XFTPClient -> IO ()) -> IO (Either XFTPClientError XFTPClient)
+getXFTPClient transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN, xftpNetworkConfig, serverVRange} presetDomains proxySessTs disconnected = runExceptT $ do
   let socksCreds = clientSocksCredentials xftpNetworkConfig proxySessTs transportSession
       ProtocolServer _ host port keyHash = srv
+      useALPN = if useWebPort xftpNetworkConfig presetDomains srv then Just [httpALPN11] else clientALPN
   useHost <- liftEither $ chooseTransportHost xftpNetworkConfig host
-  let tcConfig = transportClientConfig xftpNetworkConfig NRMBackground useHost False clientALPN
+  let tcConfig = transportClientConfig xftpNetworkConfig NRMBackground useHost False useALPN
       http2Config = xftpHTTP2Config tcConfig config
   clientVar <- newTVarIO Nothing
   let usePort = if null port then "443" else port
@@ -121,7 +147,9 @@ getXFTPClient transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN,
       thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = v, thServerVRange, thAuth = Nothing, implySessId = False, encryptBlock = Nothing, batch = True, serviceAuth = False}
   logDebug $ "Client negotiated handshake protocol: " <> tshow sessionALPN
   thParams@THandleParams {thVersion} <- case sessionALPN of
-    Just "xftp/1" -> xftpClientHandshakeV1 serverVRange keyHash http2Client thParams0
+    Just alpn
+      | alpn == xftpALPNv1 || alpn == httpALPN11 ->
+          xftpClientHandshakeV1 serverVRange keyHash http2Client thParams0
     _ -> pure thParams0
   logDebug $ "Client negotiated protocol: " <> tshow thVersion
   let c = XFTPClient {http2Client, thParams, transportSession, config}
@@ -187,7 +215,7 @@ xftpHTTP2Config transportConfig XFTPClientConfig {xftpNetworkConfig = NetworkCon
 xftpClientError :: HTTP2ClientError -> XFTPClientError
 xftpClientError = \case
   HCResponseTimeout -> PCEResponseTimeout
-  HCNetworkError -> PCENetworkError
+  HCNetworkError e -> PCENetworkError e
   HCIOError e -> PCEIOError e
 
 sendXFTPCommand :: forall p. FilePartyI p => XFTPClient -> C.APrivateAuthKey -> XFTPFileId -> FileCommand p -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
@@ -206,7 +234,7 @@ sendXFTPTransmission XFTPClient {config, thParams, http2Client} t chunkSpec_ = d
   HTTP2Response {respBody = body@HTTP2Body {bodyHead}} <- withExceptT xftpClientError . ExceptT $ sendRequest http2Client req (Just reqTimeout)
   when (B.length bodyHead /= xftpBlockSize) $ throwE $ PCEResponseError BLOCK
   -- TODO validate that the file ID is the same as in the request?
-  (_, _fId, respOrErr) <-liftEither $ first PCEResponseError $ xftpDecodeTClient thParams bodyHead
+  (_, _fId, respOrErr) <- liftEither $ first PCEResponseError $ xftpDecodeTClient thParams bodyHead
   case respOrErr of
     Right r -> case protocolError r of
       Just e -> throwE $ PCEProtocolError e
@@ -257,9 +285,9 @@ downloadXFTPChunk g c@XFTPClient {config} rpKey fId chunkSpec@XFTPRcvChunkSpec {
         ExceptT (sequence <$> (t `timeout` (download cbState `catches` errors))) >>= maybe (throwE PCEResponseTimeout) pure
         where
           errors =
-            [ Handler $ \(_e :: H.HTTP2Error) -> pure $ Left PCENetworkError,
-              Handler $ \(e :: IOException) -> pure $ Left (PCEIOError e),
-              Handler $ \(_e :: SomeException) -> pure $ Left PCENetworkError
+            [ Handler $ \(e :: H.HTTP2Error) -> pure $ Left $ PCENetworkError $ NEConnectError $ displayException e,
+              Handler $ \(e :: IOException) -> pure $ Left $ PCEIOError e,
+              Handler $ \(e :: SomeException) -> pure $ Left $ PCENetworkError $ toNetworkError e
             ]
           download cbState =
             runExceptT . withExceptT PCEResponseError $

src/Simplex/FileTransfer/Client/Agent.hs

@@ -5,7 +5,17 @@
 {-# LANGUAGE NumericUnderscores #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.FileTransfer.Client.Agent where
+module Simplex.FileTransfer.Client.Agent
+  ( XFTPClientVar,
+    XFTPClientAgent (..),
+    XFTPClientAgentConfig (..),
+    XFTPClientAgentError (..),
+    defaultXFTPClientAgentConfig,
+    newXFTPAgent,
+    getXFTPServerClient,
+    showServer,
+    closeXFTPServerClient,
+  ) where
 
 import Control.Logger.Simple (logInfo)
 import Control.Monad
@@ -71,7 +81,7 @@ getXFTPServerClient XFTPClientAgent {xftpClients, startedAt, config} srv = do
     connectClient =
       ExceptT $
         first (XFTPClientAgentError srv)
-          <$> getXFTPClient (1, srv, Nothing) (xftpConfig config) startedAt clientDisconnected
+          <$> getXFTPClient (1, srv, Nothing) (xftpConfig config) [] startedAt clientDisconnected
 
     clientDisconnected :: XFTPClient -> IO ()
     clientDisconnected _ = do

src/Simplex/FileTransfer/Client/Main.hs

@@ -16,6 +16,9 @@ module Simplex.FileTransfer.Client.Main
     xftpClientCLI,
     cliSendFile,
     cliSendFileOpts,
+    encodeWebURI,
+    decodeWebURI,
+    fileWebLink,
     singleChunkSize,
     prepareChunkSizes,
     prepareChunkSpecs,
@@ -23,6 +26,7 @@ module Simplex.FileTransfer.Client.Main
   )
 where
 
+import qualified Codec.Compression.Zlib.Raw as Z
 import Control.Logger.Simple
 import Control.Monad
 import Control.Monad.Except
@@ -30,17 +34,19 @@ import Control.Monad.Trans.Except
 import Crypto.Random (ChaChaDRG)
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Data.Bifunctor (first)
+import qualified Data.ByteString.Base64.URL as U
 import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Lazy.Char8 as LB
 import Data.Char (toLower)
 import Data.Either (partitionEithers)
 import Data.Int (Int64)
-import Data.List (foldl', sortOn)
+import Data.List (foldl', isPrefixOf, sortOn)
 import Data.List.NonEmpty (NonEmpty (..), nonEmpty)
 import qualified Data.List.NonEmpty as L
 import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as M
 import Data.Maybe (fromMaybe)
+import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Word (Word32)
 import GHC.Records (HasField (getField))
@@ -62,7 +68,7 @@ import qualified Simplex.Messaging.Crypto.Lazy as LC
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String (StrEncoding (..))
 import Simplex.Messaging.Parsers (parseAll)
-import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), SenderId, SndPrivateAuthKey, XFTPServer, XFTPServerWithAuth)
+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)
@@ -242,7 +248,8 @@ cliSendFile opts = cliSendFileOpts opts True $ printProgress "Uploaded"
 
 cliSendFileOpts :: SendOptions -> Bool -> (Int64 -> Int64 -> IO ()) -> ExceptT CLIError IO ()
 cliSendFileOpts SendOptions {filePath, outputDir, numRecipients, xftpServers, retryCount, tempPath, verbose} printInfo notifyProgress = do
-  let (_, fileName) = splitFileName filePath
+  let (_, fileNameStr) = splitFileName filePath
+      fileName = T.pack fileNameStr
   liftIO $ when printInfo $ printNoNewLine "Encrypting file..."
   g <- liftIO C.newRandom
   (encPath, fdRcv, fdSnd, chunkSpecs, encSize) <- encryptFileForUpload g fileName
@@ -254,14 +261,18 @@ cliSendFileOpts SendOptions {filePath, outputDir, numRecipients, xftpServers, re
   liftIO $ do
     let fdRcvs = createRcvFileDescriptions fdRcv sentChunks
         fdSnd' = createSndFileDescription fdSnd sentChunks
-    (fdRcvPaths, fdSndPath) <- writeFileDescriptions fileName fdRcvs fdSnd'
+    (fdRcvPaths, fdSndPath) <- writeFileDescriptions fileNameStr fdRcvs fdSnd'
     when printInfo $ do
       printNoNewLine "File uploaded!"
       putStrLn $ "\nSender file description: " <> fdSndPath
       putStrLn "Pass file descriptions to the recipient(s):"
     forM_ fdRcvPaths putStrLn
+    when printInfo $ case fdRcvs of
+      rcvFd : _ -> forM_ (fileWebLink rcvFd) $ \(host, fragment) ->
+        putStrLn $ "\nWeb link:\nhttps://" <> B.unpack host <> "/#" <> B.unpack fragment
+      _ -> pure ()
   where
-    encryptFileForUpload :: TVar ChaChaDRG -> String -> ExceptT CLIError IO (FilePath, FileDescription 'FRecipient, FileDescription 'FSender, [XFTPChunkSpec], Int64)
+    encryptFileForUpload :: TVar ChaChaDRG -> Text -> ExceptT CLIError IO (FilePath, FileDescription 'FRecipient, FileDescription 'FSender, [XFTPChunkSpec], Int64)
     encryptFileForUpload g fileName = do
       fileSize <- fromInteger <$> getFileSize filePath
       when (fileSize > maxFileSize) $ throwE $ CLIError $ "Files bigger than " <> maxFileSizeStr <> " are not supported"
@@ -387,10 +398,16 @@ cliSendFileOpts SendOptions {filePath, outputDir, numRecipients, xftpServers, re
 
 cliReceiveFile :: ReceiveOptions -> ExceptT CLIError IO ()
 cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath, verbose, yes} =
-  getFileDescription' fileDescription >>= receive
+  getInputFileDescription >>= receive 1
   where
-    receive :: ValidFileDescription 'FRecipient -> ExceptT CLIError IO ()
-    receive (ValidFileDescription FileDescription {size, digest, key, nonce, chunks}) = do
+    getInputFileDescription
+      | "http://" `isPrefixOf` fileDescription || "https://" `isPrefixOf` fileDescription = do
+          let fragment = B.pack $ drop 1 $ dropWhile (/= '#') fileDescription
+          when (B.null fragment) $ throwE $ CLIError "Invalid URL: no fragment"
+          either (throwE . CLIError . ("Invalid web link: " <>)) pure $ decodeWebURI fragment
+      | otherwise = getFileDescription' fileDescription
+    receive :: Int -> ValidFileDescription 'FRecipient -> ExceptT CLIError IO ()
+    receive depth (ValidFileDescription FileDescription {size, digest, key, nonce, chunks, redirect}) = do
       encPath <- getEncPath tempPath "xftp"
       createDirectory encPath
       a <- liftIO $ newXFTPAgent defaultXFTPClientAgentConfig
@@ -408,13 +425,26 @@ cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath,
       when (encDigest /= unFileDigest digest) $ throwE $ CLIError "File digest mismatch"
       encSize <- liftIO $ foldM (\s path -> (s +) . fromIntegral <$> getFileSize path) 0 chunkPaths
       when (FileSize encSize /= size) $ throwE $ CLIError "File size mismatch"
-      liftIO $ printNoNewLine "Decrypting file..."
-      CryptoFile path _ <- withExceptT cliCryptoError $ decryptChunks encSize chunkPaths key nonce $ fmap CF.plain . getFilePath
-      forM_ chunks $ acknowledgeFileChunk a
-      whenM (doesPathExist encPath) $ removeDirectoryRecursive encPath
-      liftIO $ do
-        printNoNewLine $ "File downloaded: " <> path
-        removeFD yes fileDescription
+      case redirect of
+        Just _
+          | depth > 0 -> do
+              CryptoFile tmpFile _ <- withExceptT cliCryptoError $ decryptChunks encSize chunkPaths key nonce $ \_ ->
+                fmap CF.plain $ uniqueCombine encPath "redirect.yaml"
+              forM_ chunks $ acknowledgeFileChunk a
+              yaml <- liftIO $ B.readFile tmpFile
+              whenM (doesPathExist encPath) $ removeDirectoryRecursive encPath
+              innerVfd <- either (throwE . CLIError . ("Redirect: invalid file description: " <>)) pure $ strDecode yaml
+              receive 0 innerVfd
+          | otherwise -> throwE $ CLIError "Redirect chain too long"
+        Nothing -> do
+          liftIO $ printNoNewLine "Decrypting file..."
+          CryptoFile path _ <- withExceptT cliCryptoError $ decryptChunks encSize chunkPaths key nonce $ fmap CF.plain . getFilePath
+          forM_ chunks $ acknowledgeFileChunk a
+          whenM (doesPathExist encPath) $ removeDirectoryRecursive encPath
+          liftIO $ do
+            printNoNewLine $ "File downloaded: " <> path
+            unless ("http://" `isPrefixOf` fileDescription || "https://" `isPrefixOf` fileDescription) $
+              removeFD yes fileDescription
     downloadFileChunk :: TVar ChaChaDRG -> XFTPClientAgent -> FilePath -> FileSize Int64 -> TVar [Int64] -> FileChunk -> ExceptT CLIError IO (Int, FilePath)
     downloadFileChunk g a encPath (FileSize encSize) downloadedChunks FileChunk {chunkNo, chunkSize, digest, replicas = replica : _} = do
       let FileChunkReplica {server, replicaId, replicaKey} = replica
@@ -430,13 +460,14 @@ cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath,
         when verbose $ putStrLn ""
       pure (chunkNo, chunkPath)
     downloadFileChunk _ _ _ _ _ _ = throwE $ CLIError "chunk has no replicas"
-    getFilePath :: String -> ExceptT String IO FilePath
-    getFilePath name =
-      case filePath of
-        Just path ->
-          ifM (doesDirectoryExist path) (uniqueCombine path name) $
-            ifM (doesFileExist path) (throwE "File already exists") (pure path)
-        _ -> (`uniqueCombine` name) . (</> "Downloads") =<< getHomeDirectory
+    getFilePath :: Text -> ExceptT String IO FilePath
+    getFilePath name = case filePath of
+      Just path ->
+        ifM (doesDirectoryExist path) (uniqueCombine path name') $
+          ifM (doesFileExist path) (throwE "File already exists") (pure path)
+      _ -> (`uniqueCombine` name') . (</> "Downloads") =<< getHomeDirectory
+      where
+        name' = T.unpack name
     acknowledgeFileChunk :: XFTPClientAgent -> FileChunk -> ExceptT CLIError IO ()
     acknowledgeFileChunk a FileChunk {replicas = replica : _} = do
       let FileChunkReplica {server, replicaId, replicaKey} = replica
@@ -552,3 +583,24 @@ cliRandomFile RandomFileOptions {filePath, fileSize = FileSize size} = do
       B.hPut h bytes
       when (sz > mb') $ saveRandomFile h (sz - mb')
     mb' = mb 1
+
+-- | Encode file description as web-compatible URI fragment.
+-- Result is base64url(deflateRaw(YAML)), no leading '#'.
+encodeWebURI :: FileDescription 'FRecipient -> B.ByteString
+encodeWebURI fd = U.encode $ LB.toStrict $ Z.compress $ LB.fromStrict $ strEncode fd
+
+-- | Decode web URI fragment to validated file description.
+-- Input is base64url-encoded DEFLATE-compressed YAML, no leading '#'.
+decodeWebURI :: B.ByteString -> Either String (ValidFileDescription 'FRecipient)
+decodeWebURI fragment = do
+  compressed <- U.decode fragment
+  let yaml = LB.toStrict $ Z.decompress $ LB.fromStrict compressed
+  strDecode yaml >>= validateFileDescription
+
+-- | Extract web link host and URI fragment from a file description.
+-- Returns (hostname, uriFragment) for https://hostname/#uriFragment.
+fileWebLink :: FileDescription 'FRecipient -> Maybe (B.ByteString, B.ByteString)
+fileWebLink fd@FileDescription {chunks} = case chunks of
+  (FileChunk {replicas = FileChunkReplica {server = ProtocolServer {host}} : _} : _) ->
+    Just (strEncode (L.head host), encodeWebURI fd)
+  _ -> Nothing

src/Simplex/FileTransfer/Client/Presets.hs

@@ -1,7 +1,9 @@
 {-# LANGUAGE OverloadedLists #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.FileTransfer.Client.Presets where
+module Simplex.FileTransfer.Client.Presets
+  ( defaultXFTPServers,
+  ) where
 
 import Data.List.NonEmpty (NonEmpty)
 import Simplex.Messaging.Protocol (XFTPServerWithAuth)

src/Simplex/FileTransfer/Crypto.hs

@@ -4,7 +4,11 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
-module Simplex.FileTransfer.Crypto where
+module Simplex.FileTransfer.Crypto
+  ( encryptFile,
+    decryptChunks,
+    readChunks,
+  ) where
 
 import Control.Monad
 import Control.Monad.Except
@@ -16,6 +20,7 @@ import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Lazy.Char8 as LB
 import Data.Int (Int64)
+import Data.Text (Text)
 import Simplex.FileTransfer.Types (FileHeader (..), authTagSize)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.File (CryptoFile (..), FTCryptoError (..))
@@ -54,7 +59,7 @@ encryptFile srcFile fileHdr key nonce fileSize' encSize encFile = do
           liftIO $ B.hPut w ch'
           encryptChunks_ get w (sb', len - chSize)
 
-decryptChunks :: Int64 -> [FilePath] -> C.SbKey -> C.CbNonce -> (String -> ExceptT String IO CryptoFile) -> ExceptT FTCryptoError IO CryptoFile
+decryptChunks :: Int64 -> [FilePath] -> C.SbKey -> C.CbNonce -> (Text -> ExceptT String IO CryptoFile) -> ExceptT FTCryptoError IO CryptoFile
 decryptChunks _ [] _ _ _ = throwE $ FTCEInvalidHeader "empty"
 decryptChunks encSize (chPath : chPaths) key nonce getDestFile = case reverse chPaths of
   [] -> do

src/Simplex/FileTransfer/Protocol.hs

@@ -14,7 +14,25 @@
 {-# LANGUAGE TypeFamilies #-}
 {-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
 
-module Simplex.FileTransfer.Protocol where
+module Simplex.FileTransfer.Protocol
+  ( FileParty (..),
+    SFileParty (..),
+    AFileParty (..),
+    FilePartyI (..),
+    FileCommand (..),
+    FileCmd (..),
+    FileInfo (..),
+    XFTPFileId,
+    FileResponse (..),
+    xftpBlockSize,
+    toFileParty,
+    aFileParty,
+    checkParty,
+    xftpEncodeAuthTransmission,
+    xftpEncodeTransmission,
+    xftpDecodeTServer,
+    xftpDecodeTClient,
+  ) where
 
 import qualified Data.Aeson.TH as J
 import Data.Bifunctor (first)

src/Simplex/FileTransfer/Server.hs

@@ -13,7 +13,10 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections #-}
 
-module Simplex.FileTransfer.Server where
+module Simplex.FileTransfer.Server
+  ( runXFTPServer,
+    runXFTPServerBlocking,
+  ) where
 
 import Control.Logger.Simple
 import Control.Monad
@@ -40,11 +43,13 @@ import GHC.IO.Handle (hSetNewlineMode)
 import GHC.IORef (atomicSwapIORef)
 import GHC.Stats (getRTSStats)
 import qualified Network.HTTP.Types as N
+import Network.HPACK.Token (tokenKey)
 import qualified Network.HTTP2.Server as H
 import Network.Socket
 import Simplex.FileTransfer.Protocol
-import Simplex.FileTransfer.Server.Control
+import Simplex.FileTransfer.Server.Control (ControlProtocol (..))
 import Simplex.FileTransfer.Server.Env
+import Simplex.FileTransfer.Server.Prometheus
 import Simplex.FileTransfer.Server.Stats
 import Simplex.FileTransfer.Server.Store
 import Simplex.FileTransfer.Server.StoreLog
@@ -57,18 +62,20 @@ import Simplex.Messaging.Protocol (BlockingInfo, EntityId (..), RcvPublicAuthKey
 import Simplex.Messaging.Server (controlPortAuth, dummyVerifyCmd, verifyCmdAuthorization)
 import Simplex.Messaging.Server.Control (CPClientRole (..))
 import Simplex.Messaging.Server.Expiration
-import Simplex.Messaging.Server.QueueStore (RoundedSystemTime, ServerEntityStatus (..), getRoundedSystemTime)
+import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
 import Simplex.Messaging.Server.Stats
+import Simplex.Messaging.SystemTime
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
-import Simplex.Messaging.Transport (CertChainPubKey (..), SessionId, THandleAuth (..), THandleParams (..), TransportPeer (..), defaultSupportedParams)
+import Simplex.Messaging.Transport (CertChainPubKey (..), SessionId, THandleAuth (..), THandleParams (..), TransportPeer (..), defaultSupportedParams, defaultSupportedParamsHTTPS)
 import Simplex.Messaging.Transport.Buffer (trimCR)
 import Simplex.Messaging.Transport.HTTP2
 import Simplex.Messaging.Transport.HTTP2.File (fileBlockSize)
-import Simplex.Messaging.Transport.HTTP2.Server
-import Simplex.Messaging.Transport.Server (runLocalTCPServer)
+import Simplex.Messaging.Transport.HTTP2.Server (runHTTP2Server)
+import Simplex.Messaging.Transport.Server (SNICredentialUsed, TransportServerConfig (..), runLocalTCPServer)
 import Simplex.Messaging.Util
 import Simplex.Messaging.Version
+import System.Environment (lookupEnv)
 import System.Exit (exitFailure)
 import System.FilePath ((</>))
 import System.IO (hPrint, hPutStrLn, universalNewlineMode)
@@ -86,9 +93,24 @@ data XFTPTransportRequest = XFTPTransportRequest
   { thParams :: THandleParamsXFTP 'TServer,
     reqBody :: HTTP2Body,
     request :: H.Request,
-    sendResponse :: H.Response -> IO ()
+    sendResponse :: H.Response -> IO (),
+    sniUsed :: SNICredentialUsed,
+    addCORS :: Bool
   }
 
+corsHeaders :: Bool -> [N.Header]
+corsHeaders addCORS
+  | addCORS = [("Access-Control-Allow-Origin", "*"), ("Access-Control-Expose-Headers", "*")]
+  | otherwise = []
+
+corsPreflightHeaders :: [N.Header]
+corsPreflightHeaders =
+  [ ("Access-Control-Allow-Origin", "*"),
+    ("Access-Control-Allow-Methods", "POST, OPTIONS"),
+    ("Access-Control-Allow-Headers", "*"),
+    ("Access-Control-Max-Age", "86400")
+  ]
+
 runXFTPServer :: XFTPServerConfig -> IO ()
 runXFTPServer cfg = do
   started <- newEmptyTMVarIO
@@ -105,50 +127,85 @@ xftpServer :: XFTPServerConfig -> TMVar Bool -> M ()
 xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpiration, fileExpiration, xftpServerVRange} started = do
   mapM_ (expireServerFiles Nothing) fileExpiration
   restoreServerStats
-  raceAny_ (runServer : expireFilesThread_ cfg <> serverStatsThread_ cfg <> controlPortThread_ cfg) `finally` stopServer
+  raceAny_
+    ( runServer
+        : expireFilesThread_ cfg
+          <> serverStatsThread_ cfg
+          <> prometheusMetricsThread_ cfg
+          <> controlPortThread_ cfg
+    )
+    `finally` stopServer
   where
     runServer :: M ()
     runServer = do
       srvCreds@(chain, pk) <- asks tlsServerCreds
+      httpCreds_ <- asks httpServerCreds
       signKey <- liftIO $ case C.x509ToPrivate' pk of
         Right pk' -> pure pk'
         Left e -> putStrLn ("Server has no valid key: " <> show e) >> exitFailure
       env <- ask
       sessions <- liftIO TM.emptyIO
       let cleanup sessionId = atomically $ TM.delete sessionId sessions
-      liftIO . runHTTP2Server started xftpPort defaultHTTP2BufferSize defaultSupportedParams srvCreds transportConfig inactiveClientExpiration cleanup $ \sessionId sessionALPN r sendResponse -> do
-        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}
-            req0 = XFTPTransportRequest {thParams = thParams0, request = r, reqBody, sendResponse}
-        flip runReaderT env $ case sessionALPN of
-          Nothing -> processRequest req0
-          Just "xftp/1" ->
-            xftpServerHandshakeV1 chain signKey sessions req0 >>= \case
-              Nothing -> pure () -- handshake response sent
-              Just thParams -> processRequest req0 {thParams} -- proceed with new version (XXX: may as well switch the request handler here)
-          _ -> liftIO . sendResponse $ H.responseNoBody N.ok200 [] -- shouldn't happen: means server picked handshake protocol it doesn't know about
+          srvParams = if isJust httpCreds_ then defaultSupportedParamsHTTPS else defaultSupportedParams
+      liftIO . runHTTP2Server started xftpPort defaultHTTP2BufferSize srvParams srvCreds httpCreds_ transportConfig inactiveClientExpiration cleanup $ \sniUsed sessionId sessionALPN r sendResponse -> do
+        let addCORS' = sniUsed && addCORSHeaders transportConfig
+        if addCORS' && H.requestMethod r == Just "OPTIONS"
+          then sendResponse $ H.responseNoBody N.ok200 corsPreflightHeaders
+          else do
+            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}
+                req0 = XFTPTransportRequest {thParams = thParams0, request = r, reqBody, sendResponse, sniUsed, addCORS = addCORS'}
+            flip runReaderT env $ case sessionALPN of
+              Nothing -> processRequest req0
+              Just alpn
+                | alpn == xftpALPNv1 || alpn == httpALPN11 || (sniUsed && alpn == "h2") ->
+                    xftpServerHandshakeV1 chain signKey sessions req0 >>= \case
+                      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 chain serverSignKey sessions XFTPTransportRequest {thParams = thParams0@THandleParams {sessionId}, reqBody = HTTP2Body {bodyHead}, sendResponse} = do
+    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
-        Nothing -> processHello
-        Just (HandshakeSent pk) -> processClientHandshake pk
-        Just (HandshakeAccepted thParams) -> pure $ Just thParams
+        Nothing
+          | sniUsed && not webHello -> throwE SESSION
+          | otherwise -> processHello Nothing
+        Just (HandshakeSent pk)
+          | webHello -> processHello (Just pk)
+          | otherwise -> processClientHandshake pk
+        Just (HandshakeAccepted thParams)
+          | webHello -> processHello (serverPrivKey <$> thAuth thParams)
+          | webHandshake, Just auth <- thAuth thParams -> processClientHandshake (serverPrivKey auth)
+          | otherwise -> pure $ Just thParams
       either sendError pure r
       where
-        processHello = do
-          unless (B.null bodyHead) $ throwE HANDSHAKE
-          (k, pk) <- atomically . C.generateKeyPair =<< asks random
-          atomically $ TM.insert sessionId (HandshakeSent pk) sessions
+        webHello = sniUsed && any (\(t, _) -> tokenKey t == "xftp-web-hello") (fst $ H.requestHeaders request)
+        webHandshake = sniUsed && any (\(t, _) -> tokenKey t == "xftp-handshake") (fst $ H.requestHeaders request)
+        processHello pk_ = do
+          challenge_ <-
+            if
+              | B.null bodyHead -> pure Nothing
+              | sniUsed -> do
+                  body <- liftHS $ C.unPad bodyHead
+                  XFTPClientHello {webChallenge} <- liftHS $ first show (smpDecode body)
+                  pure webChallenge
+              | otherwise -> throwE HANDSHAKE
+          rng <- asks random
+          k <- atomically $ TM.lookup sessionId sessions >>= \case
+            Just (HandshakeSent pk') -> pure $ C.publicKey pk'
+            _ -> do
+              kp <- maybe (C.generateKeyPair rng) (\p -> pure (C.publicKey p, p)) pk_
+              fst kp <$ TM.insert sessionId (HandshakeSent $ snd kp) sessions
           let authPubKey = CertChainPubKey chain (C.signX509 serverSignKey $ C.publicToX509 k)
-          let hs = XFTPServerHandshake {xftpVersionRange = xftpServerVRange, sessionId, authPubKey}
+              webIdentityProof = C.sign serverSignKey . (<> sessionId) <$> challenge_
+          let hs = XFTPServerHandshake {xftpVersionRange = xftpServerVRange, sessionId, authPubKey, webIdentityProof}
           shs <- encodeXftp hs
 #ifdef slow_servers
           lift randomDelay
 #endif
-          liftIO . sendResponse $ H.responseBuilder N.ok200 [] shs
+          liftIO . sendResponse $ H.responseBuilder N.ok200 (corsHeaders addCORS) shs
           pure Nothing
         processClientHandshake pk = do
           unless (B.length bodyHead == xftpBlockSize) $ throwE HANDSHAKE
@@ -164,13 +221,13 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
 #ifdef slow_servers
               lift randomDelay
 #endif
-              liftIO . sendResponse $ H.responseNoBody N.ok200 []
+              liftIO . sendResponse $ H.responseNoBody N.ok200 (corsHeaders addCORS)
               pure Nothing
             Nothing -> throwE HANDSHAKE
         sendError :: XFTPErrorType -> M (Maybe (THandleParams XFTPVersion 'TServer))
         sendError err = do
           runExceptT (encodeXftp err) >>= \case
-            Right bs -> liftIO . sendResponse $ H.responseBuilder N.ok200 [] bs
+            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
@@ -240,6 +297,30 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
               ]
         liftIO $ threadDelay' interval
 
+    prometheusMetricsThread_ :: XFTPServerConfig -> [M ()]
+    prometheusMetricsThread_ XFTPServerConfig {prometheusInterval = Just interval, prometheusMetricsFile} =
+      [savePrometheusMetrics interval prometheusMetricsFile]
+    prometheusMetricsThread_ _ = []
+
+    savePrometheusMetrics :: Int -> FilePath -> M ()
+    savePrometheusMetrics saveInterval metricsFile = do
+      labelMyThread "savePrometheusMetrics"
+      liftIO $ putStrLn $ "Prometheus metrics saved every " <> show saveInterval <> " seconds to " <> metricsFile
+      ss <- asks serverStats
+      rtsOpts <- liftIO $ maybe ("set " <> rtsOptionsEnv) T.pack <$> lookupEnv (T.unpack rtsOptionsEnv)
+      let interval = 1000000 * saveInterval
+      liftIO $ forever $ do
+        threadDelay interval
+        ts <- getCurrentTime
+        sm <- getFileServerMetrics ss rtsOpts
+        T.writeFile metricsFile $ xftpPrometheusMetrics sm ts
+
+    getFileServerMetrics :: FileServerStats -> T.Text -> IO FileServerMetrics
+    getFileServerMetrics ss rtsOptions = do
+      d <- getFileServerStatsData ss
+      let fd = periodStatDataCounts $ _filesDownloaded d
+      pure FileServerMetrics {statsData = d, filesDownloadedPeriods = fd, rtsOptions}
+
     controlPortThread_ :: XFTPServerConfig -> [M ()]
     controlPortThread_ XFTPServerConfig {controlPort = Just port} = [runCPServer port]
     controlPortThread_ _ = []
@@ -296,6 +377,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
               CPHelp -> hPutStrLn h "commands: stats-rts, delete, help, quit"
               CPQuit -> pure ()
               CPSkip -> pure ()
+              _ -> hPutStrLn h "unsupported command"
               where
                 withUserRole action =
                   readTVarIO role >>= \case
@@ -312,7 +394,7 @@ data ServerFile = ServerFile
   }
 
 processRequest :: XFTPTransportRequest -> M ()
-processRequest XFTPTransportRequest {thParams, reqBody = body@HTTP2Body {bodyHead}, sendResponse}
+processRequest XFTPTransportRequest {thParams, reqBody = body@HTTP2Body {bodyHead}, sendResponse, addCORS}
   | B.length bodyHead /= xftpBlockSize = sendXFTPResponse ("", NoEntity, FRErr BLOCK) Nothing
   | otherwise =
       case xftpDecodeTServer thParams bodyHead of
@@ -331,7 +413,7 @@ processRequest XFTPTransportRequest {thParams, reqBody = body@HTTP2Body {bodyHea
 #ifdef slow_servers
       randomDelay
 #endif
-      liftIO $ sendResponse $ H.responseStreaming N.ok200 [] $ streamBody t_
+      liftIO $ sendResponse $ H.responseStreaming N.ok200 (corsHeaders addCORS) $ streamBody t_
       where
         streamBody t_ send done = do
           case t_ of
@@ -418,7 +500,7 @@ 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 -> RoundedSystemTime -> M (Either XFTPErrorType XFTPFileId)
+    addFileRetry :: FileStore -> FileInfo -> Int -> RoundedFileTime -> M (Either XFTPErrorType XFTPFileId)
     addFileRetry st file n ts =
       retryAdd n $ \sId -> runExceptT $ do
         ExceptT $ addFile st sId file ts EntityActive
@@ -546,8 +628,8 @@ deleteOrBlockServerFile_ FileRec {filePath, fileInfo} stat storeAction = runExce
       liftIO $ atomicModifyIORef'_ (filesCount stats) (subtract 1)
       liftIO $ atomicModifyIORef'_ (filesSize stats) (subtract $ fromIntegral $ size fileInfo)
 
-getFileTime :: IO RoundedSystemTime
-getFileTime = getRoundedSystemTime fileTimePrecision
+getFileTime :: IO RoundedFileTime
+getFileTime = getRoundedSystemTime
 
 expireServerFiles :: Maybe Int -> ExpirationConfig -> M ()
 expireServerFiles itemDelay expCfg = do

src/Simplex/FileTransfer/Server/Control.hs

@@ -1,7 +1,10 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.FileTransfer.Server.Control where
+module Simplex.FileTransfer.Server.Control
+  ( ControlProtocol (..),
+  )
+where
 
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Simplex.FileTransfer.Protocol (XFTPFileId)

src/Simplex/FileTransfer/Server/Env.hs

@@ -7,7 +7,16 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE StrictData #-}
 
-module Simplex.FileTransfer.Server.Env where
+module Simplex.FileTransfer.Server.Env
+  ( XFTPServerConfig (..),
+    XFTPEnv (..),
+    XFTPRequest (..),
+    defaultInactiveClientExpiration,
+    defFileExpirationHours,
+    defaultFileExpiration,
+    newXFTPServerEnv,
+    countUsedStorage,
+  ) where
 
 import Control.Logger.Simple
 import Control.Monad
@@ -57,6 +66,7 @@ data XFTPServerConfig = XFTPServerConfig
     -- | time after which inactive clients can be disconnected and check interval, seconds
     inactiveClientExpiration :: Maybe ExpirationConfig,
     xftpCredentials :: ServerCredentials,
+    httpCredentials :: Maybe ServerCredentials,
     -- | XFTP client-server protocol version range
     xftpServerVRange :: VersionRangeXFTP,
     -- stats config - see SMP server config
@@ -64,6 +74,8 @@ data XFTPServerConfig = XFTPServerConfig
     logStatsStartTime :: Int64,
     serverStatsLogFile :: FilePath,
     serverStatsBackupFile :: Maybe FilePath,
+    prometheusInterval :: Maybe Int,
+    prometheusMetricsFile :: FilePath,
     transportConfig :: TransportServerConfig,
     responseDelay :: Int
   }
@@ -82,6 +94,7 @@ data XFTPEnv = XFTPEnv
     random :: TVar ChaChaDRG,
     serverIdentity :: C.KeyHash,
     tlsServerCreds :: T.Credential,
+    httpServerCreds :: Maybe T.Credential,
     serverStats :: FileServerStats
   }
 
@@ -96,7 +109,7 @@ defaultFileExpiration =
     }
 
 newXFTPServerEnv :: XFTPServerConfig -> IO XFTPEnv
-newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, xftpCredentials} = do
+newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, xftpCredentials, httpCredentials} = do
   random <- C.newRandom
   store <- newFileStore
   storeLog <- mapM (`readWriteFileStore` store) storeLogFile
@@ -106,9 +119,10 @@ newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, xftpCrede
     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!"
   tlsServerCreds <- loadServerCredential xftpCredentials
+  httpServerCreds <- mapM loadServerCredential httpCredentials
   Fingerprint fp <- loadFingerprint xftpCredentials
   serverStats <- newFileServerStats =<< getCurrentTime
-  pure XFTPEnv {config, store, storeLog, random, tlsServerCreds, serverIdentity = C.KeyHash fp, serverStats}
+  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

src/Simplex/FileTransfer/Server/Main.hs

@@ -6,13 +6,15 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PatternSynonyms #-}
 
-module Simplex.FileTransfer.Server.Main where
+module Simplex.FileTransfer.Server.Main
+  ( xftpServerCLI,
+  ) where
 
 import Data.Either (fromRight)
 import Data.Functor (($>))
 import Data.Ini (lookupValue, readIniFile)
 import Data.Int (Int64)
-import Data.Maybe (fromMaybe)
+import Data.Maybe (fromMaybe, isJust)
 import qualified Data.Text as T
 import qualified Data.Text.IO as T
 import Network.Socket (HostName)
@@ -21,16 +23,16 @@ 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.Transport (supportedFileServerVRange, alpnSupportedXFTPhandshakes)
+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.Server.CLI
 import Simplex.Messaging.Server.Expiration
-import Simplex.Messaging.Transport (simplexMQVersion)
 import Simplex.Messaging.Transport.Client (TransportHost (..))
-import Simplex.Messaging.Transport.Server (ServerCredentials (..), mkTransportServerConfig)
-import Simplex.Messaging.Util (safeDecodeUtf8, tshow)
+import Simplex.Messaging.Transport.HTTP2 (httpALPN)
+import Simplex.Messaging.Transport.Server (ServerCredentials (..), TransportServerConfig (..), mkTransportServerConfig)
+import Simplex.Messaging.Util (eitherToMaybe, safeDecodeUtf8, tshow)
 import System.Directory (createDirectoryIfMissing, doesFileExist)
 import System.FilePath (combine)
 import System.IO (BufferMode (..), hSetBuffering, stderr, stdout)
@@ -60,7 +62,7 @@ xftpServerCLI cfgPath logPath = do
       putStrLn "Deleted configuration and log files"
   where
     iniFile = combine cfgPath "file-server.ini"
-    serverVersion = "SimpleX XFTP server v" <> simplexMQVersion
+    serverVersion = "SimpleX XFTP server v" <> simplexmqVersionCommit
     defaultServerPort = "443"
     executableName = "file-server"
     storeLogFilePath = combine logPath "file-server-store.log"
@@ -89,6 +91,9 @@ xftpServerCLI cfgPath logPath = do
             <> "# Expire files after the specified number of hours.\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\
                \\n\
                \[AUTH]\n\
                \# Set new_files option to off to completely prohibit uploading new files.\n\
@@ -121,6 +126,10 @@ xftpServerCLI cfgPath logPath = do
                \disconnect: off\n"
             <> ("# ttl: " <> tshow (ttl defaultInactiveClientExpiration) <> "\n")
             <> ("# check_interval: " <> tshow (checkInterval defaultInactiveClientExpiration) <> "\n")
+            <> "\n\
+               \[WEB]\n\
+               \# cert: /etc/opt/simplex-xftp/web.crt\n\
+               \# key: /etc/opt/simplex-xftp/web.key\n"
     runServer ini = do
       hSetBuffering stdout LineBuffering
       hSetBuffering stderr LineBuffering
@@ -152,6 +161,17 @@ xftpServerCLI cfgPath logPath = do
                 else "NOT allowed."
           putStrLn $ "Listening on port " <> xftpPort <> "..."
 
+        httpCredentials_ =
+          eitherToMaybe $ do
+            cert <- T.unpack <$> lookupValue "WEB" "cert" ini
+            key <- T.unpack <$> lookupValue "WEB" "key" ini
+            pure
+              ServerCredentials
+                { caCertificateFile = Nothing,
+                  certificateFile = cert,
+                  privateKeyFile = key
+                }
+
         serverConfig =
           XFTPServerConfig
             { xftpPort = T.unpack $ strictIni "TRANSPORT" "port" ini,
@@ -183,16 +203,21 @@ xftpServerCLI cfgPath logPath = do
                     privateKeyFile = c serverKeyFile,
                     certificateFile = c serverCrtFile
                   },
+              httpCredentials = httpCredentials_,
               xftpServerVRange = supportedFileServerVRange,
               logStatsInterval = logStats $> 86400, -- seconds
               logStatsStartTime = 0, -- seconds from 00:00 UTC
               serverStatsLogFile = combine logPath "file-server-stats.daily.log",
               serverStatsBackupFile = logStats $> combine logPath "file-server-stats.log",
+              prometheusInterval = eitherToMaybe $ read . T.unpack <$> lookupValue "STORE_LOG" "prometheus_interval" ini,
+              prometheusMetricsFile = combine logPath "xftp-server-metrics.txt",
               transportConfig =
-                mkTransportServerConfig
-                  (fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini)
-                  (Just alpnSupportedXFTPhandshakes)
-                  False,
+                let cfg =
+                      mkTransportServerConfig
+                        (fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini)
+                        (Just $ alpnSupportedXFTPhandshakes <> httpALPN)
+                        False
+                 in cfg {addCORSHeaders = isJust httpCredentials_},
               responseDelay = 0
             }
 
@@ -224,11 +249,14 @@ cliCommandP cfgPath logPath iniFile =
     initP :: Parser InitOptions
     initP = do
       enableStoreLog <-
-        flag' False
+        flag'
+          False
           ( long "disable-store-log"
               <> help "Disable store log for persistence (enabled by default)"
           )
-          <|> flag True True
+          <|> flag
+            True
+            True
             ( long "store-log"
                 <> short 'l'
                 <> help "Enable store log for persistence (DEPRECATED, enabled by default)"

src/Simplex/FileTransfer/Server/Prometheus.hs

@@ -0,0 +1,138 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeApplications #-}
+{-# OPTIONS_GHC -fno-warn-unrecognised-pragmas #-}
+
+module Simplex.FileTransfer.Server.Prometheus
+  ( FileServerMetrics (..),
+    rtsOptionsEnv,
+    xftpPrometheusMetrics,
+  ) where
+
+import Data.Int (Int64)
+import Data.Text (Text)
+import qualified Data.Text as T
+import Data.Time.Clock (UTCTime (..), diffUTCTime)
+import Data.Time.Clock.System (systemEpochDay)
+import Data.Time.Format.ISO8601 (iso8601Show)
+import Simplex.FileTransfer.Server.Stats
+import Simplex.Messaging.Server.Stats (PeriodStatCounts (..))
+import Simplex.Messaging.Transport (simplexMQVersion)
+import Simplex.Messaging.Util (tshow)
+
+data FileServerMetrics = FileServerMetrics
+  { statsData :: FileServerStatsData,
+    filesDownloadedPeriods :: PeriodStatCounts,
+    rtsOptions :: Text
+  }
+
+rtsOptionsEnv :: Text
+rtsOptionsEnv = "XFTP_RTS_OPTIONS"
+
+{-# FOURMOLU_DISABLE\n#-}
+xftpPrometheusMetrics :: FileServerMetrics -> UTCTime -> Text
+xftpPrometheusMetrics sm ts =
+  time <> files <> info
+  where
+    FileServerMetrics {statsData, filesDownloadedPeriods, rtsOptions} = sm
+    FileServerStatsData
+      { _fromTime,
+        _filesCreated,
+        _fileRecipients,
+        _filesUploaded,
+        _filesExpired,
+        _filesDeleted,
+        _filesBlocked,
+        _fileDownloads,
+        _fileDownloadAcks,
+        _filesCount,
+        _filesSize
+      } = statsData
+    time =
+      "# Recorded at: " <> T.pack (iso8601Show ts) <> "\n\
+      \# Stats from: " <> T.pack (iso8601Show _fromTime) <> "\n\
+      \\n"
+    files =
+      "# Files\n\
+      \# -----\n\
+      \\n\
+      \# HELP simplex_xftp_files_created Created files\n\
+      \# TYPE simplex_xftp_files_created counter\n\
+      \simplex_xftp_files_created " <> mshow _filesCreated <> "\n\
+      \# filesCreated\n\
+      \\n\
+      \# HELP simplex_xftp_files_recipients Files recipients\n\
+      \# TYPE simplex_xftp_files_recipients counter\n\
+      \simplex_xftp_files_recipients " <> mshow _fileRecipients <> "\n\
+      \# fileRecipients\n\
+      \\n\
+      \# HELP simplex_xftp_files_uploaded Uploaded files\n\
+      \# TYPE simplex_xftp_files_uploaded counter\n\
+      \simplex_xftp_files_uploaded " <> mshow _filesUploaded <> "\n\
+      \# filesUploaded\n\
+      \\n\
+      \# HELP simplex_xftp_files_expired Expired files\n\
+      \# TYPE simplex_xftp_files_expired counter\n\
+      \simplex_xftp_files_expired " <> mshow _filesExpired <> "\n\
+      \# filesExpired\n\
+      \\n\
+      \# HELP simplex_xftp_files_deleted Deleted files\n\
+      \# TYPE simplex_xftp_files_deleted counter\n\
+      \simplex_xftp_files_deleted " <> mshow _filesDeleted <> "\n\
+      \# filesDeleted\n\
+      \\n\
+      \# HELP simplex_xftp_files_blocked Blocked files\n\
+      \# TYPE simplex_xftp_files_blocked counter\n\
+      \simplex_xftp_files_blocked " <> mshow _filesBlocked <> "\n\
+      \# filesBlocked\n\
+      \\n\
+      \# HELP simplex_xftp_file_downloads File downloads\n\
+      \# TYPE simplex_xftp_file_downloads counter\n\
+      \simplex_xftp_file_downloads " <> mshow _fileDownloads <> "\n\
+      \# fileDownloads\n\
+      \\n\
+      \# HELP simplex_xftp_file_download_acks File download ACKs\n\
+      \# TYPE simplex_xftp_file_download_acks counter\n\
+      \simplex_xftp_file_download_acks " <> mshow _fileDownloadAcks <> "\n\
+      \# fileDownloadAcks\n\
+      \\n\
+      \# HELP simplex_xftp_files_count_total Total files count \n\
+      \# TYPE simplex_xftp_files_count_total gauge\n\
+      \simplex_xftp_files_count_total " <> mshow _filesCount <> "\n\
+      \# filesCount\n\
+      \\n\
+      \# HELP simplex_xftp_files_size Size of files \n\
+      \# TYPE simplex_xftp_files_size gauge\n\
+      \simplex_xftp_files_size " <> mshow _filesSize <> "\n\
+      \# filesSize \n\
+      \\n\
+      \# HELP simplex_xftp_files_count_daily Daily files count\n\
+      \# TYPE simplex_xftp_files_count_daily gauge\n\
+      \simplex_xftp_files_count_daily " <> mstr (dayCount filesDownloadedPeriods) <> "\n\
+      \# filesDownloaded.dayCount\n\
+      \\n\
+      \# HELP simplex_xftp_files_count_weekly Weekly files count\n\
+      \# TYPE simplex_xftp_files_count_weekly gauge\n\
+      \simplex_xftp_files_count_weekly " <> mstr (weekCount filesDownloadedPeriods) <> "\n\
+      \# filesDownloaded.weekCount\n\
+      \\n\
+      \# HELP simplex_xftp_files_count_monthly Monthly files count\n\
+      \# TYPE simplex_xftp_files_count_monthly gauge\n\
+      \simplex_xftp_files_count_monthly " <> mstr (monthCount filesDownloadedPeriods) <> "\n\
+      \# filesDownloaded.monthCount\n\
+      \\n"
+    info =
+      "# Info\n\
+      \# ----\n\
+      \\n\
+      \# HELP simplex_xftp_info Server information. RTS options have to be passed via " <> rtsOptionsEnv <> " env var\n\
+      \# TYPE simplex_xftp_info gauge\n\
+      \simplex_xftp_info{version=\"" <> T.pack simplexMQVersion <> "\",rts_options=\"" <> rtsOptions <> "\"} 1\n\
+      \\n"
+    mstr a = a <> " " <> tsEpoch
+    mshow :: Show a => a -> Text
+    mshow = mstr . tshow
+    tsEpoch = tshow @Int64 $ floor @Double $ realToFrac (ts `diffUTCTime` epoch) * 1000
+    epoch = UTCTime systemEpochDay 0
+{-# FOURMOLU_ENABLE\n#-}

src/Simplex/FileTransfer/Server/Stats.hs

@@ -2,7 +2,13 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.FileTransfer.Server.Stats where
+module Simplex.FileTransfer.Server.Stats
+  ( FileServerStats (..),
+    FileServerStatsData (..),
+    newFileServerStats,
+    getFileServerStatsData,
+    setFileServerStats,
+  ) where
 
 import Control.Applicative ((<|>))
 import qualified Data.Attoparsec.ByteString.Char8 as A

src/Simplex/FileTransfer/Server/Store.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
@@ -8,6 +9,7 @@ module Simplex.FileTransfer.Server.Store
   ( FileStore (..),
     FileRec (..),
     FileRecipient (..),
+    RoundedFileTime,
     newFileStore,
     addFile,
     setFilePath,
@@ -33,7 +35,8 @@ 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 (RoundedSystemTime (..), ServerEntityStatus (..))
+import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
+import Simplex.Messaging.SystemTime
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Util (ifM, ($>>=))
@@ -49,10 +52,12 @@ data FileRec = FileRec
     fileInfo :: FileInfo,
     filePath :: TVar (Maybe FilePath),
     recipientIds :: TVar (Set RecipientId),
-    createdAt :: RoundedSystemTime,
+    createdAt :: RoundedFileTime,
     fileStatus :: TVar ServerEntityStatus
   }
 
+type RoundedFileTime = RoundedSystemTime 3600
+
 fileTimePrecision :: Int64
 fileTimePrecision = 3600 -- truncate creation time to 1 hour
 
@@ -70,14 +75,14 @@ newFileStore = do
   usedStorage <- newTVarIO 0
   pure FileStore {files, recipients, usedStorage}
 
-addFile :: FileStore -> SenderId -> FileInfo -> RoundedSystemTime -> ServerEntityStatus -> STM (Either XFTPErrorType ())
+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 ()
 
-newFileRec :: SenderId -> FileInfo -> RoundedSystemTime -> ServerEntityStatus -> STM FileRec
+newFileRec :: SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> STM FileRec
 newFileRec senderId fileInfo createdAt status = do
   recipientIds <- newTVar S.empty
   filePath <- newTVar Nothing

src/Simplex/FileTransfer/Server/StoreLog.hs

@@ -34,13 +34,13 @@ import Simplex.FileTransfer.Protocol (FileInfo (..))
 import Simplex.FileTransfer.Server.Store
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (BlockingInfo, RcvPublicAuthKey, RecipientId, SenderId)
-import Simplex.Messaging.Server.QueueStore (RoundedSystemTime, ServerEntityStatus (..))
+import Simplex.Messaging.Server.QueueStore (ServerEntityStatus (..))
 import Simplex.Messaging.Server.StoreLog
 import Simplex.Messaging.Util (bshow)
 import System.IO
 
 data FileStoreLogRecord
-  = AddFile SenderId FileInfo RoundedSystemTime ServerEntityStatus
+  = AddFile SenderId FileInfo RoundedFileTime ServerEntityStatus
   | PutFile SenderId FilePath
   | AddRecipients SenderId (NonEmpty FileRecipient)
   | DeleteFile SenderId
@@ -69,7 +69,7 @@ instance StrEncoding FileStoreLogRecord where
 logFileStoreRecord :: StoreLog 'WriteMode -> FileStoreLogRecord -> IO ()
 logFileStoreRecord = writeStoreLogRecord
 
-logAddFile :: StoreLog 'WriteMode -> SenderId -> FileInfo -> RoundedSystemTime -> ServerEntityStatus -> IO ()
+logAddFile :: StoreLog 'WriteMode -> SenderId -> FileInfo -> RoundedFileTime -> ServerEntityStatus -> IO ()
 logAddFile s = logFileStoreRecord s .:: AddFile
 
 logPutFile :: StoreLog 'WriteMode -> SenderId -> FilePath -> IO ()

src/Simplex/FileTransfer/Transport.hs

@@ -14,10 +14,12 @@ module Simplex.FileTransfer.Transport
     blockedFilesXFTPVersion,
     xftpClientHandshakeStub,
     alpnSupportedXFTPhandshakes,
+    xftpALPNv1,
     XFTPClientHandshake (..),
     -- xftpClientHandshake,
     XFTPServerHandshake (..),
     -- xftpServerHandshake,
+    XFTPClientHello (..),
     THandleXFTP,
     THandleParamsXFTP,
     VersionXFTP,
@@ -34,6 +36,7 @@ module Simplex.FileTransfer.Transport
   )
 where
 
+import Control.Applicative (optional)
 import qualified Control.Exception as E
 import Control.Logger.Simple
 import Control.Monad
@@ -59,7 +62,7 @@ import Simplex.Messaging.Parsers
 import Simplex.Messaging.Protocol (BlockingInfo, CommandError)
 import Simplex.Messaging.Transport (ALPN, CertChainPubKey, ServiceCredentials, SessionId, THandle (..), THandleParams (..), TransportError (..), TransportPeer (..))
 import Simplex.Messaging.Transport.HTTP2.File
-import Simplex.Messaging.Util (bshow, tshow)
+import Simplex.Messaging.Util (bshow, tshow, (<$?>))
 import Simplex.Messaging.Version
 import Simplex.Messaging.Version.Internal
 import System.IO (Handle, IOMode (..), withFile)
@@ -105,13 +108,23 @@ xftpClientHandshakeStub :: c 'TClient -> Maybe C.KeyPairX25519 -> C.KeyHash -> V
 xftpClientHandshakeStub _c _ks _keyHash _xftpVRange _proxyServer _serviceKeys = throwE TEVersion
 
 alpnSupportedXFTPhandshakes :: [ALPN]
-alpnSupportedXFTPhandshakes = ["xftp/1"]
+alpnSupportedXFTPhandshakes = [xftpALPNv1]
+
+xftpALPNv1 :: ALPN
+xftpALPNv1 = "xftp/1"
+
+data XFTPClientHello = XFTPClientHello
+  { -- | a random string sent by the client to the server to prove that server has identity certificate
+    webChallenge :: Maybe ByteString
+  }
 
 data XFTPServerHandshake = XFTPServerHandshake
   { xftpVersionRange :: VersionRangeXFTP,
     sessionId :: SessionId,
     -- | pub key to agree shared secrets for command authorization and entity ID encryption.
-    authPubKey :: CertChainPubKey
+    authPubKey :: CertChainPubKey,
+    -- | signed identity challenge from  XFTPClientHello
+    webIdentityProof :: Maybe C.ASignature
   }
 
 data XFTPClientHandshake = XFTPClientHandshake
@@ -121,6 +134,14 @@ data XFTPClientHandshake = XFTPClientHandshake
     keyHash :: C.KeyHash
   }
 
+instance Encoding XFTPClientHello where
+  smpEncode XFTPClientHello {webChallenge} = smpEncode webChallenge
+  smpP = do
+    webChallenge <- smpP
+    forM_ webChallenge $ \challenge -> unless (B.length challenge == 32) $ fail "bad XFTPClientHello webChallenge"
+    Tail _compat <- smpP
+    pure XFTPClientHello {webChallenge}
+
 instance Encoding XFTPClientHandshake where
   smpEncode XFTPClientHandshake {xftpVersion, keyHash} =
     smpEncode (xftpVersion, keyHash)
@@ -130,13 +151,13 @@ instance Encoding XFTPClientHandshake where
     pure XFTPClientHandshake {xftpVersion, keyHash}
 
 instance Encoding XFTPServerHandshake where
-  smpEncode XFTPServerHandshake {xftpVersionRange, sessionId, authPubKey} =
-    smpEncode (xftpVersionRange, sessionId, authPubKey)
+  smpEncode XFTPServerHandshake {xftpVersionRange, sessionId, authPubKey, webIdentityProof} =
+    smpEncode (xftpVersionRange, sessionId, authPubKey, C.signatureBytes webIdentityProof)
   smpP = do
-    (xftpVersionRange, sessionId) <- smpP
-    authPubKey <- smpP
+    (xftpVersionRange, sessionId, authPubKey) <- smpP
+    webIdentityProof <- optional $ C.decodeSignature <$?> smpP
     Tail _compat <- smpP
-    pure XFTPServerHandshake {xftpVersionRange, sessionId, authPubKey}
+    pure XFTPServerHandshake {xftpVersionRange, sessionId, authPubKey, webIdentityProof}
 
 sendEncFile :: Handle -> (Builder -> IO ()) -> LC.SbState -> Word32 -> IO ()
 sendEncFile h send = go

src/Simplex/FileTransfer/Types.hs

@@ -4,17 +4,42 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TemplateHaskell #-}
 
-module Simplex.FileTransfer.Types where
+module Simplex.FileTransfer.Types
+  ( RcvFileId,
+    SndFileId,
+    FileHeader (..),
+    DBRcvFileId,
+    RcvFile (..),
+    RcvFileStatus (..),
+    RcvFileChunk (..),
+    RcvFileChunkReplica (..),
+    RcvFileRedirect (..),
+    DBSndFileId,
+    SndFile (..),
+    SndFileStatus (..),
+    SndFileChunk (..),
+    NewSndChunkReplica (..),
+    SndFileChunkReplica (..),
+    SndFileReplicaStatus (..),
+    DeletedSndChunkReplica (..),
+    SentRecipientReplica (..),
+    FileErrorType (..),
+    authTagSize,
+    sndFileEncPath,
+    sndChunkSize,
+  ) where
 
 import qualified Data.Aeson.TH as J
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Data.ByteString.Char8 (ByteString)
 import Data.Int (Int64)
+import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
 import Data.Word (Word32)
 import Simplex.FileTransfer.Client (XFTPChunkSpec (..))
 import Simplex.FileTransfer.Description
+import Simplex.Messaging.Agent.Store.DB (FromField (..), ToField (..), fromTextField_)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.File (CryptoFile (..))
 import Simplex.Messaging.Encoding
@@ -22,7 +47,6 @@ import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Parsers
 import Simplex.Messaging.Protocol (XFTPServer)
 import System.FilePath ((</>))
-import Simplex.Messaging.Agent.Store.DB (FromField (..), ToField (..), fromTextField_)
 
 type RcvFileId = ByteString -- Agent entity ID
 
@@ -33,8 +57,8 @@ authTagSize = fromIntegral C.authTagSize
 
 -- fileExtra is added to allow header extension in future versions
 data FileHeader = FileHeader
-  { fileName :: String,
-    fileExtra :: Maybe String
+  { fileName :: Text,
+    fileExtra :: Maybe Text
   }
   deriving (Eq, Show)
 

src/Simplex/Messaging/Agent/Env/SQLite.hs

@@ -27,11 +27,6 @@ module Simplex.Messaging.Agent.Env.SQLite
     serverHosts,
     defaultAgentConfig,
     defaultReconnectInterval,
-    tryAgentError,
-    tryAgentError',
-    catchAgentError,
-    catchAgentError',
-    agentFinally,
     Env (..),
     newSMPAgentEnv,
     createAgentStore,
@@ -45,7 +40,6 @@ module Simplex.Messaging.Agent.Env.SQLite
 where
 
 import Control.Concurrent (ThreadId)
-import Control.Exception (BlockedIndefinitelyOnSTM (..), SomeException, fromException)
 import Control.Monad.Except
 import Control.Monad.IO.Unlift
 import Control.Monad.Reader
@@ -70,7 +64,7 @@ import Simplex.Messaging.Agent.RetryInterval
 import Simplex.Messaging.Agent.Store (createStore)
 import Simplex.Messaging.Agent.Store.Common (DBStore)
 import Simplex.Messaging.Agent.Store.Interface (DBOpts)
-import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation (..), MigrationError (..))
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfig (..), MigrationError (..))
 import Simplex.Messaging.Client
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.Ratchet (VersionRangeE2E, supportedE2EEncryptVRange)
@@ -83,7 +77,6 @@ import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport (SMPVersion)
 import Simplex.Messaging.Transport.Client (TransportHost)
-import Simplex.Messaging.Util (allFinally, catchAllErrors, catchAllErrors', tryAllErrors, tryAllErrors')
 import System.Mem.Weak (Weak)
 import System.Random (StdGen, newStdGen)
 import UnliftIO.STM
@@ -97,7 +90,8 @@ data InitialAgentServers = InitialAgentServers
     ntf :: [NtfServer],
     xftp :: Map UserId (NonEmpty (ServerCfg 'PXFTP)),
     netCfg :: NetworkConfig,
-    presetDomains :: [HostName]
+    presetDomains :: [HostName],
+    presetServers :: [SMPServer]
   }
 
 data ServerCfg p = ServerCfg
@@ -159,6 +153,7 @@ data AgentConfig = AgentConfig
     persistErrorInterval :: NominalDiffTime,
     initialCleanupDelay :: Int64,
     cleanupInterval :: Int64,
+    cleanupBatchSize :: Int,
     initialLogStatsDelay :: Int64,
     logStatsInterval :: Int64,
     cleanupStepInterval :: Int,
@@ -173,6 +168,7 @@ data AgentConfig = AgentConfig
     ntfBatchSize :: Int,
     ntfSubFirstCheckInterval :: NominalDiffTime,
     ntfSubCheckInterval :: NominalDiffTime,
+    maxPendingSubscriptions :: Int,
     caCertificateFile :: FilePath,
     privateKeyFile :: FilePath,
     certificateFile :: FilePath,
@@ -229,7 +225,8 @@ defaultAgentConfig =
       quotaExceededTimeout = 7 * nominalDay,
       persistErrorInterval = 3, -- seconds
       initialCleanupDelay = 30 * 1000000, -- 30 seconds
-      cleanupInterval = 30 * 60 * 1000000, -- 30 minutes
+      cleanupInterval = 5 * 60 * 1000000, -- 5 minutes
+      cleanupBatchSize = 10000,
       initialLogStatsDelay = 10 * 1000000, -- 10 seconds
       logStatsInterval = 10 * 1000000, -- 10 seconds
       cleanupStepInterval = 200000, -- 200ms
@@ -244,6 +241,7 @@ defaultAgentConfig =
       ntfBatchSize = 150,
       ntfSubFirstCheckInterval = nominalDay,
       ntfSubCheckInterval = 3 * nominalDay,
+      maxPendingSubscriptions = 35000,
       -- CA certificate private key is not needed for initialization
       -- ! we do not generate these
       caCertificateFile = "/etc/opt/simplex-agent/ca.crt",
@@ -273,7 +271,7 @@ newSMPAgentEnv config store = do
   multicastSubscribers <- newTMVarIO 0
   pure Env {config, store, random, randomServer, ntfSupervisor, xftpAgent, multicastSubscribers}
 
-createAgentStore :: DBOpts -> MigrationConfirmation -> IO (Either MigrationError DBStore)
+createAgentStore :: DBOpts -> MigrationConfig -> IO (Either MigrationError DBStore)
 createAgentStore = createStore
 
 data NtfSupervisor = NtfSupervisor
@@ -312,33 +310,6 @@ newXFTPAgent = do
   xftpDelWorkers <- TM.emptyIO
   pure XFTPAgent {xftpWorkDir, xftpRcvWorkers, xftpSndWorkers, xftpDelWorkers}
 
-tryAgentError :: AM a -> AM (Either AgentErrorType a)
-tryAgentError = tryAllErrors mkInternal
-{-# INLINE tryAgentError #-}
-
--- unlike runExceptT, this ensures we catch IO exceptions as well
-tryAgentError' :: AM a -> AM' (Either AgentErrorType a)
-tryAgentError' = tryAllErrors' mkInternal
-{-# INLINE tryAgentError' #-}
-
-catchAgentError :: AM a -> (AgentErrorType -> AM a) -> AM a
-catchAgentError = catchAllErrors mkInternal
-{-# INLINE catchAgentError #-}
-
-catchAgentError' :: AM a -> (AgentErrorType -> AM' a) -> AM' a
-catchAgentError' = catchAllErrors' mkInternal
-{-# INLINE catchAgentError' #-}
-
-agentFinally :: AM a -> AM b -> AM a
-agentFinally = allFinally mkInternal
-{-# INLINE agentFinally #-}
-
-mkInternal :: SomeException -> AgentErrorType
-mkInternal e = case fromException e of
-  Just BlockedIndefinitelyOnSTM -> CRITICAL True "Thread blocked indefinitely in STM transaction"
-  _ -> INTERNAL $ show e
-{-# INLINE mkInternal #-}
-
 data Worker = Worker
   { workerId :: Int,
     doWork :: TMVar (),

src/Simplex/Messaging/Agent/NtfSubSupervisor.hs

@@ -36,6 +36,7 @@ import qualified Data.List.NonEmpty as L
 import qualified Data.Map.Strict as M
 import Data.Maybe (catMaybes)
 import qualified Data.Set as S
+import qualified Data.Text as T
 import Data.Time (UTCTime, addUTCTime, getCurrentTime)
 import Data.Time.Clock (diffUTCTime)
 import Simplex.Messaging.Agent.Client
@@ -46,13 +47,13 @@ import Simplex.Messaging.Agent.Stats
 import Simplex.Messaging.Agent.Store
 import Simplex.Messaging.Agent.Store.AgentStore
 import qualified Simplex.Messaging.Agent.Store.DB as DB
-import Simplex.Messaging.Client (NetworkRequestMode (..))
+import Simplex.Messaging.Client (NetworkRequestMode (..), nonBlockingWriteTBQueue)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Notifications.Protocol
 import Simplex.Messaging.Notifications.Types
 import Simplex.Messaging.Protocol (NtfServer, sameSrvAddr)
 import qualified Simplex.Messaging.Protocol as SMP
-import Simplex.Messaging.Util (diffToMicroseconds, threadDelay', tshow, whenM)
+import Simplex.Messaging.Util (catchAllErrors, catchAllErrors', diffToMicroseconds, threadDelay', tryAllErrors, tshow, whenM)
 import System.Random (randomR)
 import UnliftIO
 import UnliftIO.Concurrent (forkIO)
@@ -66,19 +67,15 @@ runNtfSupervisor c = do
     Right _ -> pure ()
   forever $ do
     cmd <- atomically . readTBQueue $ ntfSubQ ns
-    handleErr . agentOperationBracket c AONtfNetwork waitUntilActive $
-      runExceptT (processNtfCmd c cmd) >>= \case
-        Left e -> notifyErr e
-        Right _ -> return ()
+    handleErr $ agentOperationBracket c AONtfNetwork waitUntilActive $
+      processNtfCmd c cmd `catchAllErrors'` notifyErr
   where
     startTknDelete :: AM ()
     startTknDelete = do
       pendingDelServers <- withStore' c getPendingDelTknServers
       lift . forM_ pendingDelServers $ getNtfTknDelWorker True c
     handleErr :: AM' () -> AM' ()
-    handleErr = E.handle $ \(e :: E.SomeException) -> do
-      logError $ "runNtfSupervisor error " <> tshow e
-      notifyErr e
+    handleErr = E.handle $ \(e :: E.SomeException) -> notifyErr e
     notifyErr e = notifyInternalError' c $ "runNtfSupervisor error " <> show e
 
 partitionErrs :: (a -> ConnId) -> [a] -> [Either AgentErrorType b] -> ([(ConnId, AgentErrorType)], [b])
@@ -217,7 +214,7 @@ runNtfWorker c srv Worker {doWork} =
     runNtfOperation :: AM ()
     runNtfOperation = do
       ntfBatchSize <- asks $ ntfBatchSize . config
-      withWorkItems c doWork (\db -> getNextNtfSubNTFActions db srv ntfBatchSize) $ \nextSubs -> do
+      withWorkItems c doWork (withStore' c $ \db -> getNextNtfSubNTFActions db srv ntfBatchSize) $ \nextSubs -> do
         logInfo $ "runNtfWorker - length nextSubs = " <> tshow (length nextSubs)
         currTs <- liftIO getCurrentTime
         let (creates, checks, deletes, rotates) = splitActions currTs nextSubs
@@ -357,7 +354,7 @@ runNtfWorker c srv Worker {doWork} =
     runCatching :: (NtfSubscription -> AM (Maybe NtfSubscription)) -> NtfSubscription -> AM' (Maybe NtfSubscription)
     runCatching action sub@NtfSubscription {connId} =
       fromRight Nothing
-        <$> runExceptT (action sub `catchAgentError` \e -> workerInternalError c connId (show e) $> Nothing)
+        <$> runExceptT (action sub `catchAllErrors` \e -> workerInternalError c connId (show e) $> Nothing)
     -- deleteNtfSub is only used in NSADelete and NSARotate, so also deprecated
     deleteNtfSub :: NtfSubscription -> AM () -> AM (Maybe NtfSubscription)
     deleteNtfSub sub@NtfSubscription {userId, ntfSubId} continue = case ntfSubId of
@@ -365,7 +362,7 @@ runNtfWorker c srv Worker {doWork} =
         lift getNtfToken >>= \case
           Just tkn@NtfToken {ntfServer} -> do
             atomically $ incNtfServerStat c userId ntfServer ntfDelAttempts
-            tryAgentError (agentNtfDeleteSubscription c nSubId tkn) >>= \case
+            tryAllErrors (agentNtfDeleteSubscription c nSubId tkn) >>= \case
               Right _ -> do
                 atomically $ incNtfServerStat c userId ntfServer ntfDeleted
                 continue'
@@ -385,7 +382,7 @@ runNtfSMPWorker c srv Worker {doWork} = forever $ do
     runNtfSMPOperation :: AM ()
     runNtfSMPOperation = do
       ntfBatchSize <- asks $ ntfBatchSize . config
-      withWorkItems c doWork (\db -> getNextNtfSubSMPActions db srv ntfBatchSize) $ \nextSubs -> do
+      withWorkItems c doWork (withStore' c $ \db -> getNextNtfSubSMPActions db srv ntfBatchSize) $ \nextSubs -> do
         logInfo $ "runNtfSMPWorker - length nextSubs = " <> tshow (length nextSubs)
         let (creates, deletes) = splitActions nextSubs
         retrySubActions c creates createNotifierKeys
@@ -505,16 +502,18 @@ workerInternalError c connId internalErrStr = do
 
 -- TODO change error
 notifyInternalError :: MonadIO m => AgentClient -> ConnId -> String -> m ()
-notifyInternalError AgentClient {subQ} connId internalErrStr = atomically $ writeTBQueue subQ ("", connId, AEvt SAEConn $ ERR $ INTERNAL internalErrStr)
-{-# INLINE notifyInternalError #-}
+notifyInternalError AgentClient {subQ} connId internalErrStr = do
+  logError $ T.pack internalErrStr
+  liftIO $ nonBlockingWriteTBQueue subQ ("", connId, AEvt SAEConn $ ERR $ INTERNAL internalErrStr)
 
 notifyInternalError' :: MonadIO m => AgentClient -> String -> m ()
-notifyInternalError' AgentClient {subQ} internalErrStr = atomically $ writeTBQueue subQ ("", "", AEvt SAEConn $ ERR $ INTERNAL internalErrStr)
+notifyInternalError' c = notifyInternalError c ""
 {-# INLINE notifyInternalError' #-}
 
 notifyErrs :: MonadIO m => AgentClient -> [(ConnId, AgentErrorType)] -> m ()
-notifyErrs AgentClient {subQ} connErrs = unless (null connErrs) $ atomically $ writeTBQueue subQ ("", "", AEvt SAENone $ ERRS connErrs)
-{-# INLINE notifyErrs #-}
+notifyErrs c errs_ = forM_ (L.nonEmpty errs_) $ \errs -> do
+  logError $ "notifyErrs: " <> tshow errs
+  notifySub c $ ERRS errs
 
 getNtfToken :: AM' (Maybe NtfToken)
 getNtfToken = do
@@ -567,7 +566,7 @@ runNtfTknDelWorker c srv Worker {doWork} =
           withRetryInterval ri $ \_ loop -> do
             liftIO $ waitWhileSuspended c
             liftIO $ waitForUserNetwork c
-            processTknToDelete nextTknToDelete `catchAgentError` retryTmpError loop nextTknToDelete
+            processTknToDelete nextTknToDelete `catchAllErrors` retryTmpError loop nextTknToDelete
     retryTmpError :: AM () -> NtfTokenToDelete -> AgentErrorType -> AM ()
     retryTmpError loop (tknDbId, _, _) e = do
       logError $ "ntf tkn del error: " <> tshow e

src/Simplex/Messaging/Agent/Protocol.hs

@@ -20,8 +20,8 @@
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UndecidableInstances #-}
-{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
 {-# OPTIONS_GHC -fno-warn-ambiguous-fields #-}
+{-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
 
 -- |
 -- Module      : Simplex.Messaging.Agent.Protocol
@@ -70,6 +70,7 @@ module Simplex.Messaging.Agent.Protocol
     MsgMeta (..),
     RcvQueueInfo (..),
     SndQueueInfo (..),
+    SubscriptionStatus (..),
     ConnectionStats (..),
     SwitchPhase (..),
     RcvSwitchStatus (..),
@@ -106,11 +107,16 @@ module Simplex.Messaging.Agent.Protocol
     ConnectionModeI (..),
     ConnectionRequestUri (..),
     AConnectionRequestUri (..),
+    ShortLinkCreds (..),
     ConnReqUriData (..),
     CRClientData,
     ServiceScheme,
     FixedLinkData (..),
+    AConnLinkData (..),
     ConnLinkData (..),
+    AUserConnLinkData (..),
+    UserConnLinkData (..),
+    UserContactData (..),
     UserLinkData (..),
     OwnerAuth (..),
     OwnerId,
@@ -123,9 +129,12 @@ module Simplex.Messaging.Agent.Protocol
     ContactConnType (..),
     ShortLinkScheme (..),
     LinkKey (..),
+    PreparedLinkParams (..),
     StoredClientService (..),
     ClientService,
     ClientServiceId,
+    validateOwners,
+    validateLinkOwners,
     sameConnReqContact,
     sameShortLinkContact,
     simplexChat,
@@ -167,12 +176,14 @@ module Simplex.Messaging.Agent.Protocol
     updateSMPServerHosts,
     shortenShortLink,
     restoreShortLink,
+    isPresetServer,
     linkUserData,
     linkUserData',
   )
 where
 
 import Control.Applicative (optional, (<|>))
+import Control.Exception (BlockedIndefinitelyOnMVar (..), BlockedIndefinitelyOnSTM (..), fromException)
 import Data.Aeson (FromJSON (..), ToJSON (..), Value (..), (.:), (.:?))
 import qualified Data.Aeson as J'
 import qualified Data.Aeson.Encoding as JE
@@ -192,7 +203,7 @@ import Data.List.NonEmpty (NonEmpty (..))
 import qualified Data.List.NonEmpty as L
 import Data.Map.Strict (Map)
 import qualified Data.Map.Strict as M
-import Data.Maybe (fromMaybe, isJust)
+import Data.Maybe (fromMaybe, isJust, isNothing)
 import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Text.Encoding (decodeLatin1, encodeUtf8)
@@ -246,10 +257,10 @@ import Simplex.Messaging.Protocol
     legacyStrEncodeServer,
     noAuthSrv,
     sameSrvAddr,
+    senderCanSecure,
+    shortLinksSMPClientVersion,
     sndAuthKeySMPClientVersion,
     srvHostnamesSMPClientVersion,
-    shortLinksSMPClientVersion,
-    senderCanSecure,
     pattern ProtoServerWithAuth,
     pattern SMPServer,
   )
@@ -377,6 +388,8 @@ type SndQueueSecured = Bool
 -- | Parameterized type for SMP agent events
 data AEvent (e :: AEntity) where
   INV :: AConnectionRequestUri -> Maybe ClientServiceId -> AEvent AEConn
+  LINK :: ConnShortLink 'CMContact -> UserConnLinkData 'CMContact -> AEvent AEConn
+  LDATA :: FixedLinkData 'CMContact -> ConnLinkData '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
   INFO :: PQSupport -> ConnInfo -> AEvent AEConn
@@ -404,7 +417,7 @@ data AEvent (e :: AEntity) where
   OK :: AEvent AEConn
   JOINED :: SndQueueSecured -> Maybe ClientServiceId -> AEvent AEConn
   ERR :: AgentErrorType -> AEvent AEConn
-  ERRS :: [(ConnId, AgentErrorType)] -> AEvent AENone
+  ERRS :: NonEmpty (ConnId, AgentErrorType) -> AEvent AENone
   SUSPENDED :: AEvent AENone
   RFPROG :: Int64 -> Int64 -> AEvent AERcvFile
   RFDONE :: FilePath -> AEvent AERcvFile
@@ -430,6 +443,8 @@ deriving instance Show AEvtTag
 
 data ACommand
   = NEW Bool AConnectionMode InitialKeys SubscriptionMode -- response INV
+  | LSET (UserConnLinkData 'CMContact) (Maybe CRClientData) -- response LINK
+  | LGET (ConnShortLink 'CMContact) -- response LDATA
   | JOIN Bool AConnectionRequestUri PQSupport SubscriptionMode ConnInfo
   | LET ConfirmationId ConnInfo -- ConnInfo is from client
   | ACK AgentMsgId (Maybe MsgReceiptInfo)
@@ -439,6 +454,8 @@ data ACommand
 
 data ACommandTag
   = NEW_
+  | LSET_
+  | LGET_
   | JOIN_
   | LET_
   | ACK_
@@ -448,6 +465,8 @@ data ACommandTag
 
 data AEventTag (e :: AEntity) where
   INV_ :: AEventTag AEConn
+  LINK_ :: AEventTag AEConn
+  LDATA_ :: AEventTag AEConn
   CONF_ :: AEventTag AEConn
   REQ_ :: AEventTag AEConn
   INFO_ :: AEventTag AEConn
@@ -494,6 +513,8 @@ deriving instance Show (AEventTag e)
 aCommandTag :: ACommand -> ACommandTag
 aCommandTag = \case
   NEW {} -> NEW_
+  LSET {} -> LSET_
+  LGET _ -> LGET_
   JOIN {} -> JOIN_
   LET {} -> LET_
   ACK {} -> ACK_
@@ -503,6 +524,8 @@ aCommandTag = \case
 aEventTag :: AEvent e -> AEventTag e
 aEventTag = \case
   INV {} -> INV_
+  LINK {} -> LINK_
+  LDATA {} -> LDATA_
   CONF {} -> CONF_
   REQ {} -> REQ_
   INFO {} -> INFO_
@@ -642,23 +665,34 @@ instance FromJSON RatchetSyncState where
 
 data RcvQueueInfo = RcvQueueInfo
   { rcvServer :: SMPServer,
+    status :: QueueStatus,
     rcvSwitchStatus :: Maybe RcvSwitchStatus,
-    canAbortSwitch :: Bool
+    canAbortSwitch :: Bool,
+    subStatus :: SubscriptionStatus
   }
   deriving (Eq, Show)
 
 data SndQueueInfo = SndQueueInfo
   { sndServer :: SMPServer,
+    status :: QueueStatus,
     sndSwitchStatus :: Maybe SndSwitchStatus
   }
   deriving (Eq, Show)
 
+data SubscriptionStatus
+  = SSActive
+  | SSPending
+  | SSRemoved {subError :: String}
+  | SSNoSub
+  deriving (Eq, Ord, Show)
+
 data ConnectionStats = ConnectionStats
   { connAgentVersion :: VersionSMPA,
     rcvQueuesInfo :: [RcvQueueInfo],
     sndQueuesInfo :: [SndQueueInfo],
     ratchetSyncState :: RatchetSyncState,
-    ratchetSyncSupported :: Bool
+    ratchetSyncSupported :: Bool,
+    subStatus :: Maybe SubscriptionStatus
   }
   deriving (Eq, Show)
 
@@ -682,9 +716,9 @@ instance ToJSON NotificationsMode where
 instance FromJSON NotificationsMode where
   parseJSON = strParseJSON "NotificationsMode"
 
-instance ToField NotificationsMode where toField = toField . strEncode
+instance ToField NotificationsMode where toField = toField . decodeLatin1 . strEncode
 
-instance FromField NotificationsMode where fromField = blobFieldDecoder $ parseAll strP
+instance FromField NotificationsMode where fromField = fromTextField_ $ eitherToMaybe . strDecode . encodeUtf8
 
 data NotificationInfo = NotificationInfo
   { ntfConnId :: ConnId,
@@ -1129,7 +1163,7 @@ instance StrEncoding AConnectionRequestUri where
 
 connReqUriP :: Maybe ServiceScheme -> Parser AConnectionRequestUri
 connReqUriP overrideScheme = do
-  crScheme <- (`fromMaybe` overrideScheme) <$> strP
+  crScheme <- (`fromMaybe` overrideScheme) <$> strP -- always parse, but use the passed one if any
   crMode <- A.char '/' *> crModeP <* optional (A.char '/') <* "#/?"
   query <- strP
   aVRange <- queryParam "v" query
@@ -1416,6 +1450,15 @@ instance Eq AConnectionRequestUri where
 
 deriving instance Show AConnectionRequestUri
 
+data ShortLinkCreds = ShortLinkCreds
+  { shortLinkId :: SMP.LinkId,
+    shortLinkKey :: LinkKey,
+    linkPrivSigKey :: C.PrivateKeyEd25519,
+    linkRootSigKey :: Maybe C.PublicKeyEd25519, -- in case the current user is not the original owner, and the root key is different from linkPrivSigKey
+    linkEncFixedData :: SMP.EncFixedDataBytes
+  }
+  deriving (Show)
+
 data ShortLinkScheme = SLSSimplex | SLSServer deriving (Eq, Show)
 
 data ConnShortLink (m :: ConnectionMode) where
@@ -1437,6 +1480,23 @@ newtype LinkKey = LinkKey ByteString -- sha3-256(fixed_data)
 
 instance ToField LinkKey where toField (LinkKey s) = toField $ Binary s
 
+-- | Parameters for creating a connection with a prepared link.
+data PreparedLinkParams = PreparedLinkParams
+  { -- | Correlation ID / determines sender ID
+    plpNonce :: C.CbNonce,
+    -- | Queue E2EE DH key pair
+    plpQueueE2EKeys :: C.KeyPairX25519,
+    -- | For encrypting link data
+    plpLinkKey :: LinkKey,
+    -- | Root signing key (for signing link data)
+    plpRootPrivKey :: C.PrivateKeyEd25519,
+    -- | smpEncode of FixedLinkData (includes linkEntityId)
+    plpSignedFixedData :: ByteString,
+    -- | Server with basic auth (not stored in link)
+    plpSrvWithAuth :: SMPServerWithAuth
+  }
+  deriving (Show)
+
 instance ConnectionModeI c => ToField (ConnectionLink c) where toField = toField . Binary . strEncode
 
 instance (Typeable c, ConnectionModeI c) => FromField (ConnectionLink c) where fromField = blobFieldDecoder strDecode
@@ -1445,7 +1505,7 @@ instance ConnectionModeI c => ToField (ConnShortLink c) where toField = toField
 
 instance (Typeable c, ConnectionModeI c) => FromField (ConnShortLink c) where fromField = blobFieldDecoder strDecode
 
-data ContactConnType = CCTContact | CCTChannel | CCTGroup deriving (Eq, Show)
+data ContactConnType = CCTContact | CCTChannel | CCTGroup | CCTRelay deriving (Eq, Show)
 
 data AConnShortLink = forall m. ConnectionModeI m => ACSL (SConnectionMode m) (ConnShortLink m)
 
@@ -1593,6 +1653,7 @@ ctTypeP = \case
   'A' -> pure CCTContact
   'C' -> pure CCTChannel
   'G' -> pure CCTGroup
+  'R' -> pure CCTRelay
   _ -> fail "unknown contact address type"
 {-# INLINE ctTypeP #-}
 
@@ -1601,6 +1662,7 @@ ctTypeChar = \case
   CCTContact -> 'A'
   CCTChannel -> 'C'
   CCTGroup -> 'G'
+  CCTRelay -> 'R'
 {-# INLINE ctTypeChar #-}
 
 -- the servers passed to this function should be all preset servers, not servers configured by the user.
@@ -1609,15 +1671,16 @@ shortenShortLink presetSrvs = \case
   CSLInvitation sch srv lnkId linkKey -> CSLInvitation sch (shortServer srv) lnkId linkKey
   CSLContact sch ct srv linkKey -> CSLContact sch ct (shortServer srv) linkKey
   where
-    shortServer srv@(SMPServer hs@(h :| _) p kh) =
-      if isPresetServer then SMPServerOnlyHost h else srv
-      where
-        isPresetServer = case findPresetServer srv presetSrvs of
-          Just (SMPServer hs' p' kh') ->
-            all (`elem` hs') hs
-              && (p == p' || (null p' && (p == "443" || p == "5223")))
-              && kh == kh'
-          Nothing -> False
+    shortServer srv@(SMPServer (h :| _) _ _) =
+      if isPresetServer srv presetSrvs then SMPServerOnlyHost h else srv
+
+isPresetServer :: Foldable t => SMPServer -> t SMPServer -> Bool
+isPresetServer srv@(SMPServer hs p kh) presetSrvs = case findPresetServer srv presetSrvs of
+  Just (SMPServer hs' p' kh') ->
+    all (`elem` hs') hs
+      && (p == p' || (null p' && (p == "443" || p == "5223")))
+      && kh == kh'
+  Nothing -> False
 
 -- explicit bidirectional is used for ghc 8.10.7 compatibility, [h]/[] patterns are not reversible.
 pattern SMPServerOnlyHost :: TransportHost -> SMPServer
@@ -1635,7 +1698,7 @@ restoreShortLink presetSrvs = \case
       s@(SMPServerOnlyHost _) -> fromMaybe s $ findPresetServer s presetSrvs
       s -> s
 
-findPresetServer :: SMPServer -> NonEmpty SMPServer -> Maybe SMPServer
+findPresetServer :: Foldable t => SMPServer -> t SMPServer -> Maybe SMPServer
 findPresetServer ProtocolServer {host = h :| _} = find (\ProtocolServer {host = h' :| _} -> h == h')
 {-# INLINE findPresetServer #-}
 
@@ -1668,30 +1731,49 @@ type CRClientData = Text
 data FixedLinkData c = FixedLinkData
   { agentVRange :: VersionRangeSMPA,
     rootKey :: C.PublicKeyEd25519,
-    connReq :: ConnectionRequestUri c
+    linkConnReq :: ConnectionRequestUri c,
+    linkEntityId :: Maybe ByteString
   }
+  deriving (Eq, Show)
 
 data ConnLinkData c where
   InvitationLinkData :: VersionRangeSMPA -> UserLinkData -> ConnLinkData 'CMInvitation
-  ContactLinkData ::
-    { agentVRange :: VersionRangeSMPA,
-      -- direct connection via connReq in fixed data is allowed.
-      direct :: Bool,
-      -- additional owner keys to sign changes of mutable data.
-      owners :: [OwnerAuth],
-      -- alternative addresses of chat relays that receive requests for this contact address.
-      relays :: [ConnShortLink 'CMContact],
-      userData :: UserLinkData
-    } -> ConnLinkData 'CMContact
+  ContactLinkData :: VersionRangeSMPA -> UserContactData -> ConnLinkData 'CMContact
+
+deriving instance Eq (ConnLinkData c)
+
+deriving instance Show (ConnLinkData c)
+
+data UserContactData = UserContactData
+  { -- direct connection via connReq in fixed data is allowed.
+    direct :: Bool,
+    -- additional owner keys to sign changes of mutable data.
+    owners :: [OwnerAuth],
+    -- alternative addresses of chat relays that receive requests for this contact address.
+    relays :: [ConnShortLink 'CMContact],
+    userData :: UserLinkData
+  }
+  deriving (Eq, Show)
 
 newtype UserLinkData = UserLinkData ByteString
+  deriving (Eq, Show)
 
 data AConnLinkData = forall m. ConnectionModeI m => ACLD (SConnectionMode m) (ConnLinkData m)
 
+data UserConnLinkData c where
+  UserInvLinkData :: UserLinkData -> UserConnLinkData 'CMInvitation
+  UserContactLinkData :: UserContactData -> UserConnLinkData 'CMContact
+
+deriving instance Eq (UserConnLinkData m)
+
+deriving instance Show (UserConnLinkData m)
+
+data AUserConnLinkData = forall m. ConnectionModeI m => AULD (SConnectionMode m) (UserConnLinkData m)
+
 linkUserData :: ConnLinkData c -> UserLinkData
 linkUserData = \case
   InvitationLinkData _ d -> d
-  ContactLinkData {userData} -> userData
+  ContactLinkData _ UserContactData {userData} -> userData
 {-# INLINE linkUserData #-}
 
 linkUserData' :: ConnLinkData c -> ByteString
@@ -1703,37 +1785,60 @@ type OwnerId = ByteString
 data OwnerAuth = OwnerAuth
   { ownerId :: OwnerId, -- unique in the list, application specific - e.g., MemberId
     ownerKey :: C.PublicKeyEd25519,
-    -- sender ID signed with ownerKey,
-    -- confirms that the owner accepts being the owner.
-    -- sender ID is used here as it is immutable for the queue, link data can be removed.
-    ownerSig :: C.Signature 'C.Ed25519,
-    -- null for root key authorization
-    authOwnerId :: OwnerId,
-    -- owner authorization, sig(ownerId || ownerKey, key(authOwnerId)),
-    -- where authOwnerId is either null for a root key or some other owner authorized by root key, etc.
-    -- Owner validation should detect and reject loops.
+    -- owner authorization by root or any previous owner, sig(ownerId || ownerKey, prevOwnerKey),
     authOwnerSig :: C.Signature 'C.Ed25519
   }
+  deriving (Eq, Show)
 
 instance Encoding OwnerAuth where
-  smpEncode OwnerAuth {ownerId, ownerKey, ownerSig, authOwnerId, authOwnerSig} =
-    smpEncode (ownerId, ownerKey, C.signatureBytes ownerSig, authOwnerId, C.signatureBytes authOwnerSig)
+  smpEncode OwnerAuth {ownerId, ownerKey, authOwnerSig} =
+    -- It is additionally encoded as ByteString to have known length and allow OwnerAuth extension
+    smpEncode $ smpEncode (ownerId, ownerKey, C.signatureBytes authOwnerSig)
   smpP = do
-    (ownerId, ownerKey, ownerSig, authOwnerId, authOwnerSig) <- smpP
-    pure OwnerAuth {ownerId, ownerKey, ownerSig, authOwnerId, authOwnerSig}
+    -- parseOnly ignores any unused extension
+    (ownerId, ownerKey, authOwnerSig) <- A.parseOnly smpP <$?> smpP
+    pure OwnerAuth {ownerId, ownerKey, authOwnerSig}
+
+validateOwners :: Maybe ShortLinkCreds -> UserContactData -> Either String ()
+validateOwners shortLink_ UserContactData {owners} = case shortLink_ of
+  Nothing
+    | null owners -> Right ()
+    | otherwise -> Left "no link credentials with additional owners"
+  Just ShortLinkCreds {linkPrivSigKey, linkRootSigKey}
+    | hasOwner -> validateLinkOwners (fromMaybe k linkRootSigKey) owners
+    | otherwise -> Left "no current owner in link data"
+    where
+      hasOwner = isNothing linkRootSigKey || any ((k ==) . ownerKey) owners
+      k = C.publicKey linkPrivSigKey
+
+validateLinkOwners :: C.PublicKeyEd25519 -> [OwnerAuth] -> Either String ()
+validateLinkOwners rootKey = go []
+  where
+    go _ [] = Right ()
+    go prev (o : os) = validOwner o >> go (o : prev) os
+      where
+        validOwner OwnerAuth {ownerId = oId, ownerKey = k, authOwnerSig = sig}
+          | k == rootKey = Left $ "owner key for ID " <> idStr <> " matches root key"
+          | any duplicate prev = Left $ "duplicate owner key or ID " <> idStr
+          | signedBy rootKey || any (signedBy . ownerKey) prev = Right ()
+          | otherwise = Left $ "invalid authorization of owner ID " <> idStr
+          where
+            duplicate OwnerAuth {ownerId, ownerKey} = oId == ownerId || k == ownerKey
+            idStr = B.unpack $ B64.encodeUnpadded oId
+            signedBy k' = C.verify' k' sig (oId <> C.encodePubKey k)
 
 instance ConnectionModeI c => Encoding (FixedLinkData c) where
-  smpEncode FixedLinkData {agentVRange, rootKey, connReq} =
-    smpEncode (agentVRange, rootKey, connReq)
+  smpEncode FixedLinkData {agentVRange, rootKey, linkConnReq, linkEntityId} =
+    smpEncode (agentVRange, rootKey, linkConnReq) <> maybe "" smpEncode linkEntityId
   smpP = do
-    (agentVRange, rootKey, connReq) <- smpP
-    pure FixedLinkData {agentVRange, rootKey, connReq}
+    (agentVRange, rootKey, linkConnReq) <- smpP
+    linkEntityId <- optional smpP <* A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
+    pure FixedLinkData {agentVRange, rootKey, linkConnReq, linkEntityId}
 
 instance ConnectionModeI c => Encoding (ConnLinkData c) where
   smpEncode = \case
     InvitationLinkData vr userData -> smpEncode (CMInvitation, vr, userData)
-    ContactLinkData {agentVRange, direct, owners, relays, userData} ->
-      B.concat [smpEncode (CMContact, agentVRange, direct), smpEncodeList owners, smpEncodeList relays, smpEncode userData]
+    ContactLinkData vr cd -> smpEncode (CMContact, vr, cd)
   smpP = (\(ACLD _ d) -> checkConnMode d) <$?> smpP
   {-# INLINE smpP #-}
 
@@ -1746,11 +1851,42 @@ instance Encoding AConnLinkData where
         (vr, userData) <- smpP <* A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
         pure $ ACLD SCMInvitation $ InvitationLinkData vr userData
       CMContact -> do
-        (agentVRange, direct) <- smpP
-        owners <- smpListP
-        relays <- smpListP
+        (vr, cd) <- smpP
+        pure $ ACLD SCMContact $ ContactLinkData vr cd
+
+instance ConnectionModeI c => Encoding (UserConnLinkData c) where
+  smpEncode = \case
+    UserInvLinkData userData -> smpEncode (CMInvitation, userData)
+    UserContactLinkData cd -> smpEncode (CMContact, cd)
+  smpP = (\(AULD _ d) -> checkConnMode d) <$?> smpP
+  {-# INLINE smpP #-}
+
+instance Encoding AUserConnLinkData where
+  smpEncode (AULD _ d) = smpEncode d
+  {-# INLINE smpEncode #-}
+  smpP =
+    smpP >>= \case
+      CMInvitation -> do
         userData <- smpP <* A.takeByteString -- ignoring tail for forward compatibility with the future link data encoding
-        pure $ ACLD SCMContact ContactLinkData {agentVRange, direct, owners, relays, userData}
+        pure $ AULD SCMInvitation $ UserInvLinkData userData
+      CMContact ->
+        AULD SCMContact . UserContactLinkData <$> smpP
+
+instance ConnectionModeI c => StrEncoding (UserConnLinkData c) where
+  strEncode = smpEncode
+  {-# INLINE strEncode #-}
+  strP = smpP
+  {-# INLINE strP #-}
+
+instance Encoding UserContactData where
+  smpEncode UserContactData {direct, owners, relays, userData} =
+    B.concat [smpEncode direct, smpEncodeList owners, smpEncodeList relays, smpEncode userData]
+  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}
 
 instance Encoding UserLinkData where
   smpEncode (UserLinkData s) = if B.length s <= 254 then smpEncode s else smpEncode ('\255', Large s)
@@ -1856,6 +1992,8 @@ data AgentErrorType
     BROKER {brokerAddress :: String, brokerErr :: BrokerErrorType}
   | -- | errors of other agents
     AGENT {agentErr :: SMPAgentError}
+  | -- | client notice
+    NOTICE {server :: Text, preset :: Bool, expiresAt :: Maybe UTCTime}
   | -- | agent implementation or dependency errors
     INTERNAL {internalErr :: String}
   | -- | critical agent errors that should be shown to the user, optionally with restart button
@@ -1864,6 +2002,14 @@ data AgentErrorType
     INACTIVE
   deriving (Eq, Show, Exception)
 
+instance AnyError AgentErrorType where
+  fromSomeException e = case fromException e of
+    Just BlockedIndefinitelyOnSTM -> CRITICAL True "Thread blocked indefinitely in STM transaction"
+    _ -> case fromException e of
+      Just BlockedIndefinitelyOnMVar -> CRITICAL True "Thread blocked indefinitely on MVar"
+      _ -> INTERNAL $ show e
+  {-# INLINE fromSomeException #-}
+
 -- | SMP agent protocol command or response error.
 data CommandErrorType
   = -- | command is prohibited in this context
@@ -1943,6 +2089,8 @@ instance StrEncoding ACommandTag where
   strP =
     A.takeTill (== ' ') >>= \case
       "NEW" -> pure NEW_
+      "LSET" -> pure LSET_
+      "LGET" -> pure LGET_
       "JOIN" -> pure JOIN_
       "LET" -> pure LET_
       "ACK" -> pure ACK_
@@ -1951,6 +2099,8 @@ instance StrEncoding ACommandTag where
       _ -> fail "bad ACommandTag"
   strEncode = \case
     NEW_ -> "NEW"
+    LSET_ -> "LSET"
+    LGET_ -> "LGET"
     JOIN_ -> "JOIN"
     LET_ -> "LET"
     ACK_ -> "ACK"
@@ -1962,6 +2112,8 @@ commandP binaryP =
   strP
     >>= \case
       NEW_ -> s (NEW <$> strP_ <*> strP_ <*> pqIKP <*> (strP <|> pure SMP.SMSubscribe))
+      LSET_ -> s (LSET <$> strP <*> optional (A.space *> strP))
+      LGET_ -> s (LGET <$> strP)
       JOIN_ -> s (JOIN <$> strP_ <*> strP_ <*> pqSupP <*> (strP_ <|> pure SMP.SMSubscribe) <*> binaryP)
       LET_ -> s (LET <$> A.takeTill (== ' ') <* A.space <*> binaryP)
       ACK_ -> s (ACK <$> A.decimal <*> optional (A.space *> binaryP))
@@ -1979,6 +2131,8 @@ commandP binaryP =
 serializeCommand :: ACommand -> ByteString
 serializeCommand = \case
   NEW ntfs cMode pqIK subMode -> s (NEW_, ntfs, cMode, pqIK, subMode)
+  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)
   LET confId cInfo -> B.unwords [s LET_, confId, serializeBinary cInfo]
   ACK mId rcptInfo_ -> s (ACK_, mId) <> maybe "" (B.cons ' ' . serializeBinary) rcptInfo_
@@ -1991,6 +2145,10 @@ serializeCommand = \case
 serializeBinary :: ByteString -> ByteString
 serializeBinary body = bshow (B.length body) <> "\n" <> body
 
+$(J.deriveJSON (enumJSON fstToLower) ''QueueStatus)
+
+$(J.deriveJSON (sumTypeJSON $ dropPrefix "SS") ''SubscriptionStatus)
+
 $(J.deriveJSON defaultJSON ''RcvQueueInfo)
 
 $(J.deriveJSON defaultJSON ''SndQueueInfo)

src/Simplex/Messaging/Agent/QueryString.hs

@@ -1,4 +1,11 @@
-module Simplex.Messaging.Agent.QueryString where
+module Simplex.Messaging.Agent.QueryString
+  ( QueryStringParams (..),
+    QSPEscaping (..),
+    queryParam,
+    queryParamParser,
+    queryParam_,
+    queryParamStr,
+  ) where
 
 import Data.Attoparsec.ByteString.Char8 (Parser)
 import qualified Data.Attoparsec.ByteString.Char8 as A

src/Simplex/Messaging/Agent/Stats.hs

@@ -3,7 +3,32 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE TemplateHaskell #-}
 
-module Simplex.Messaging.Agent.Stats where
+module Simplex.Messaging.Agent.Stats
+  ( AgentSMPServerStats (..),
+    AgentSMPServerStatsData (..),
+    OptionalInt (..),
+    AgentXFTPServerStats (..),
+    AgentXFTPServerStatsData (..),
+    AgentNtfServerStats (..),
+    AgentNtfServerStatsData (..),
+    AgentPersistedServerStats (..),
+    OptionalMap (..),
+    newAgentSMPServerStats,
+    newAgentSMPServerStatsData,
+    newAgentSMPServerStats',
+    getAgentSMPServerStats,
+    addSMPStatsData,
+    newAgentXFTPServerStats,
+    newAgentXFTPServerStatsData,
+    newAgentXFTPServerStats',
+    getAgentXFTPServerStats,
+    addXFTPStatsData,
+    newAgentNtfServerStats,
+    newAgentNtfServerStatsData,
+    newAgentNtfServerStats',
+    getAgentNtfServerStats,
+    addNtfStatsData,
+  ) where
 
 import Data.Aeson (FromJSON (..), FromJSONKey, ToJSON (..))
 import qualified Data.Aeson.TH as J

src/Simplex/Messaging/Agent/Store.hs

@@ -14,9 +14,81 @@
 {-# LANGUAGE StandaloneDeriving #-}
 {-# OPTIONS_GHC -fno-warn-unticked-promoted-constructors #-}
 
-module Simplex.Messaging.Agent.Store where
+module Simplex.Messaging.Agent.Store
+  ( RcvQueue,
+    NewRcvQueue,
+    StoredRcvQueue (..),
+    RcvQueueSub (..),
+    ClientNtfCreds (..),
+    InvShortLink (..),
+    SndQueue,
+    NewSndQueue,
+    StoredSndQueue (..),
+    SMPQueueRec (..),
+    SomeRcvQueue (..),
+    ConnType (..),
+    Connection' (..),
+    Connection,
+    SConnType (..),
+    SomeConn' (..),
+    SomeConn,
+    SomeConnSub,
+    ConnData (..),
+    NoticeId,
+    PendingCommand (..),
+    AgentCmdType (..),
+    AgentCommand (..),
+    AgentCommandTag (..),
+    InternalCommand (..),
+    InternalCommandTag (..),
+    NewConfirmation (..),
+    AcceptedConfirmation (..),
+    NewInvitation (..),
+    Invitation (..),
+    PrevExternalSndId,
+    PrevRcvMsgHash,
+    PrevSndMsgHash,
+    RcvMsgData (..),
+    RcvMsg (..),
+    SndMsgData (..),
+    SndMsgPrepData (..),
+    SndMsg (..),
+    PendingMsgData (..),
+    PendingMsgPrepData (..),
+    InternalRcvId (..),
+    ExternalSndId,
+    ExternalSndTs,
+    BrokerId,
+    BrokerTs,
+    InternalSndId (..),
+    MsgBase (..),
+    InternalId (..),
+    InternalTs,
+    AsyncCmdId,
+    StoreError (..),
+    AnyStoreError (..),
+    createStore,
+    rcvQueueSub,
+    clientServiceId,
+    rcvSMPQueueAddress,
+    canAbortRcvSwitch,
+    findQ,
+    removeQ,
+    removeQP,
+    sndAddress,
+    findRQ,
+    switchingRQ,
+    updatedQs,
+    toConnData,
+    updateConnection,
+    connType,
+    ratchetSyncAllowed,
+    ratchetSyncSendProhibited,
+    agentCommandTag,
+    internalCmdTag,
+  ) where
 
-import Control.Exception (Exception)
+import Control.Exception (Exception (..))
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Data.ByteString.Char8 (ByteString)
 import Data.Int (Int64)
@@ -29,10 +101,12 @@ import Data.Time (UTCTime)
 import Data.Type.Equality
 import Simplex.Messaging.Agent.Protocol
 import Simplex.Messaging.Agent.RetryInterval (RI2State)
+import Simplex.Messaging.Agent.Store.Entity
 import Simplex.Messaging.Agent.Store.Common
+import Simplex.Messaging.Agent.Store.DB (SQLError)
 import Simplex.Messaging.Agent.Store.Interface (createDBStore)
 import Simplex.Messaging.Agent.Store.Migrations.App (appMigrations)
-import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation (..), MigrationError (..))
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfig (..), MigrationError (..))
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.Ratchet (MsgEncryptKeyX448, PQEncryption, PQSupport, RatchetX448)
 import Simplex.Messaging.Encoding.String
@@ -48,13 +122,12 @@ import Simplex.Messaging.Protocol
     RcvNtfDhSecret,
     RcvPrivateAuthKey,
     SndPrivateAuthKey,
-    SndPublicAuthKey,
     VersionSMPC,
   )
 import qualified Simplex.Messaging.Protocol as SMP
-import Simplex.Messaging.Agent.Store.Entity
+import Simplex.Messaging.Util (AnyError (..), bshow)
 
-createStore :: DBOpts -> MigrationConfirmation -> IO (Either MigrationError DBStore)
+createStore :: DBOpts -> MigrationConfig -> IO (Either MigrationError DBStore)
 createStore dbOpts = createDBStore dbOpts appMigrations
 
 -- * Queue types
@@ -88,6 +161,10 @@ data StoredRcvQueue (q :: DBStored) = RcvQueue
     clientService :: Maybe (StoredClientService q),
     -- | queue status
     status :: QueueStatus,
+    -- | to enable notifications for this queue - this field is duplicated from ConnData
+    enableNtfs :: Bool,
+    -- | client notice
+    clientNoticeId :: Maybe NoticeId,
     -- | database queue ID (within connection)
     dbQueueId :: DBEntityId' q,
     -- | True for a primary or a next primary queue of the connection (next if dbReplaceQueueId is set)
@@ -103,22 +180,29 @@ data StoredRcvQueue (q :: DBStored) = RcvQueue
   }
   deriving (Show)
 
-data ShortLinkCreds = ShortLinkCreds
-  { shortLinkId :: SMP.LinkId,
-    shortLinkKey :: LinkKey,
-    linkPrivSigKey :: C.PrivateKeyEd25519,
-    linkEncFixedData :: SMP.EncFixedDataBytes
+data RcvQueueSub = RcvQueueSub
+  { userId :: UserId,
+    connId :: ConnId,
+    server :: SMPServer,
+    rcvId :: SMP.RecipientId,
+    rcvPrivateKey :: RcvPrivateAuthKey,
+    status :: QueueStatus,
+    enableNtfs :: Bool,
+    clientNoticeId :: Maybe NoticeId,
+    dbQueueId :: Int64,
+    primary :: Bool,
+    dbReplaceQueueId :: Maybe Int64
   }
   deriving (Show)
 
+rcvQueueSub :: RcvQueue -> RcvQueueSub
+rcvQueueSub RcvQueue {userId, connId, server, rcvId, rcvPrivateKey, status, enableNtfs, clientNoticeId, dbQueueId = DBEntityId dbQueueId, primary, dbReplaceQueueId} =
+  RcvQueueSub {userId, connId, server, rcvId, rcvPrivateKey, status, enableNtfs, clientNoticeId, dbQueueId, primary, dbReplaceQueueId}
+
 clientServiceId :: RcvQueue -> Maybe ClientServiceId
 clientServiceId = fmap dbServiceId . clientService
 {-# INLINE clientServiceId #-}
 
-rcvQueueInfo :: RcvQueue -> RcvQueueInfo
-rcvQueueInfo rq@RcvQueue {server, rcvSwchStatus} =
-  RcvQueueInfo {rcvServer = server, rcvSwitchStatus = rcvSwchStatus, canAbortSwitch = canAbortRcvSwitch rq}
-
 rcvSMPQueueAddress :: RcvQueue -> SMPQueueAddress
 rcvSMPQueueAddress RcvQueue {server, sndId, e2ePrivKey, queueMode} =
   SMPQueueAddress server sndId (C.publicKey e2ePrivKey) queueMode
@@ -154,7 +238,6 @@ data InvShortLink = InvShortLink
     linkId :: SMP.LinkId,
     linkKey :: LinkKey,
     sndPrivateKey :: SndPrivateAuthKey, -- stored to allow retries
-    sndPublicKey :: SndPublicAuthKey,
     sndId :: Maybe SMP.SenderId
   }
   deriving (Show)
@@ -172,9 +255,7 @@ data StoredSndQueue (q :: DBStored) = SndQueue
     sndId :: SMP.SenderId,
     -- | sender can secure the queue
     queueMode :: Maybe QueueMode,
-    -- | key pair used by the sender to authorize transmissions
-    -- TODO combine keys to key pair so that types match
-    sndPublicKey :: SndPublicAuthKey,
+    -- | sender key used to authorize transmissions
     sndPrivateKey :: SndPrivateAuthKey,
     -- | DH public key used to negotiate per-queue e2e encryption
     e2ePubKey :: Maybe C.PublicKeyX25519,
@@ -194,10 +275,6 @@ data StoredSndQueue (q :: DBStored) = SndQueue
   }
   deriving (Show)
 
-sndQueueInfo :: SndQueue -> SndQueueInfo
-sndQueueInfo SndQueue {server, sndSwchStatus} =
-  SndQueueInfo {sndServer = server, sndSwitchStatus = sndSwchStatus}
-
 instance SMPQueue RcvQueue where
   qServer RcvQueue {server} = server
   {-# INLINE qServer #-}
@@ -210,6 +287,12 @@ instance SMPQueue NewRcvQueue where
   queueId RcvQueue {rcvId} = rcvId
   {-# INLINE queueId #-}
 
+instance SMPQueue RcvQueueSub where
+  qServer RcvQueueSub {server} = server
+  {-# INLINE qServer #-}
+  queueId RcvQueueSub {rcvId} = rcvId
+  {-# INLINE queueId #-}
+
 instance SMPQueue SndQueue where
   qServer SndQueue {server} = server
   {-# INLINE qServer #-}
@@ -249,6 +332,7 @@ class SMPQueue q => SMPQueueRec q where
   qUserId :: q -> UserId
   qConnId :: q -> ConnId
   dbQId :: q -> Int64
+  qPrimary :: q -> Bool
   dbReplaceQId :: q -> Maybe Int64
 
 instance SMPQueueRec RcvQueue where
@@ -258,9 +342,23 @@ instance SMPQueueRec RcvQueue where
   {-# INLINE qConnId #-}
   dbQId RcvQueue {dbQueueId = DBEntityId qId} = qId
   {-# INLINE dbQId #-}
+  qPrimary RcvQueue {primary} = primary
+  {-# INLINE qPrimary #-}
   dbReplaceQId RcvQueue {dbReplaceQueueId} = dbReplaceQueueId
   {-# INLINE dbReplaceQId #-}
 
+instance SMPQueueRec RcvQueueSub where
+  qUserId RcvQueueSub {userId} = userId
+  {-# INLINE qUserId #-}
+  qConnId RcvQueueSub {connId} = connId
+  {-# INLINE qConnId #-}
+  dbQId RcvQueueSub {dbQueueId} = dbQueueId
+  {-# INLINE dbQId #-}
+  qPrimary RcvQueueSub {primary} = primary
+  {-# INLINE qPrimary #-}
+  dbReplaceQId RcvQueueSub {dbReplaceQueueId} = dbReplaceQueueId
+  {-# INLINE dbReplaceQId #-}
+
 instance SMPQueueRec SndQueue where
   qUserId SndQueue {userId} = userId
   {-# INLINE qUserId #-}
@@ -268,9 +366,22 @@ instance SMPQueueRec SndQueue where
   {-# INLINE qConnId #-}
   dbQId SndQueue {dbQueueId = DBEntityId qId} = qId
   {-# INLINE dbQId #-}
+  qPrimary SndQueue {primary} = primary
+  {-# INLINE qPrimary #-}
   dbReplaceQId SndQueue {dbReplaceQueueId} = dbReplaceQueueId
   {-# INLINE dbReplaceQId #-}
 
+class SMPQueueRec q => SomeRcvQueue q where
+  rcvAuthKey :: q -> RcvPrivateAuthKey
+
+instance SomeRcvQueue RcvQueue where
+  rcvAuthKey RcvQueue {rcvPrivateKey} = rcvPrivateKey
+  {-# INLINE rcvAuthKey #-}
+
+instance SomeRcvQueue RcvQueueSub where
+  rcvAuthKey RcvQueueSub {rcvPrivateKey} = rcvPrivateKey
+  {-# INLINE rcvAuthKey #-}
+
 -- * Connection types
 
 -- | Type of a connection.
@@ -286,16 +397,18 @@ data ConnType = CNew | CRcv | CSnd | CDuplex | CContact deriving (Eq, Show)
 --
 -- - DuplexConnection is a connection that has both receive and send queues set up,
 --   typically created by upgrading a receive or a send connection with a missing queue.
-data Connection (d :: ConnType) where
-  NewConnection :: ConnData -> Connection CNew
-  RcvConnection :: ConnData -> RcvQueue -> Connection CRcv
-  SndConnection :: ConnData -> SndQueue -> Connection CSnd
-  DuplexConnection :: ConnData -> NonEmpty RcvQueue -> NonEmpty SndQueue -> Connection CDuplex
-  ContactConnection :: ConnData -> RcvQueue -> Connection CContact
+data Connection' (d :: ConnType) rq sq where
+  NewConnection :: ConnData -> Connection' CNew rq sq
+  RcvConnection :: ConnData -> rq -> Connection' CRcv rq sq
+  SndConnection :: ConnData -> sq -> Connection' CSnd rq sq
+  DuplexConnection :: ConnData -> NonEmpty rq -> NonEmpty sq -> Connection' CDuplex rq sq
+  ContactConnection :: ConnData -> rq -> Connection' CContact rq sq
 
-deriving instance Show (Connection d)
+deriving instance (Show rq, Show sq) => Show (Connection' d rq sq)
 
-toConnData :: Connection d -> ConnData
+type Connection d = Connection' d RcvQueue SndQueue
+
+toConnData :: Connection' d rq sq -> ConnData
 toConnData = \case
   NewConnection cData -> cData
   RcvConnection cData _ -> cData
@@ -303,7 +416,7 @@ toConnData = \case
   DuplexConnection cData _ _ -> cData
   ContactConnection cData _ -> cData
 
-updateConnection :: ConnData -> Connection d -> Connection d
+updateConnection :: ConnData -> Connection' d rq sq -> Connection' d rq sq
 updateConnection cData = \case
   NewConnection _ -> NewConnection cData
   RcvConnection _ rq -> RcvConnection cData rq
@@ -336,9 +449,13 @@ instance TestEquality SConnType where
 
 -- | Connection of an unknown type.
 -- Used to refer to an arbitrary connection when retrieving from store.
-data SomeConn = forall d. SomeConn (SConnType d) (Connection d)
+data SomeConn' rq sq = forall d. SomeConn (SConnType d) (Connection' d rq sq)
 
-deriving instance Show SomeConn
+deriving instance (Show rq, Show sq) => Show (SomeConn' rq sq)
+
+type SomeConn = SomeConn' RcvQueue SndQueue
+
+type SomeConnSub = SomeConn' RcvQueueSub SndQueue
 
 data ConnData = ConnData
   { connId :: ConnId,
@@ -352,6 +469,8 @@ data ConnData = ConnData
   }
   deriving (Eq, Show)
 
+type NoticeId = Int64
+
 -- this function should be mirrored in the clients
 ratchetSyncAllowed :: ConnData -> Bool
 ratchetSyncAllowed ConnData {ratchetSyncState, connAgentVersion} =
@@ -672,7 +791,7 @@ data StoreError
   | -- | Invitation not found
     SEInvitationNotFound String InvitationId
   | -- | Message not found
-    SEMsgNotFound
+    SEMsgNotFound String
   | -- | Command not found
     SECmdNotFound
   | -- | Currently not used. The intention was to pass current expected queue status in methods,
@@ -692,7 +811,22 @@ data StoreError
   | -- | XFTP Deleted snd chunk replica not found.
     SEDeletedSndChunkReplicaNotFound
   | -- | Error when reading work item that suspends worker - do not use!
-    SEWorkItemError ByteString
+    SEWorkItemError {errContext :: String}
   | -- | Servers stats not found.
     SEServersStatsNotFound
   deriving (Eq, Show, Exception)
+
+instance AnyError StoreError where
+  fromSomeException e = SEInternal $ case fromException e of
+    Just (e' :: SQLError) -> bshow e'
+    Nothing -> bshow e
+
+class (Show e, AnyError e) => AnyStoreError e where
+  isWorkItemError :: e -> Bool
+  mkWorkItemError :: String -> e
+
+instance AnyStoreError StoreError where
+  isWorkItemError = \case
+    SEWorkItemError {} -> True
+    _ -> False
+  mkWorkItemError errContext = SEWorkItemError {errContext}

src/Simplex/Messaging/Agent/Store/Entity.hs

@@ -8,7 +8,12 @@
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeApplications #-}
 
-module Simplex.Messaging.Agent.Store.Entity where
+module Simplex.Messaging.Agent.Store.Entity
+  ( DBStored (..),
+    DBEntityId,
+    DBEntityId' (..),
+  )
+where
 
 import Data.Aeson (FromJSON (..), ToJSON (..))
 import qualified Data.Aeson as J

src/Simplex/Messaging/Agent/Store/Migrations.hs

@@ -15,7 +15,7 @@ where
 import Control.Monad
 import Data.Char (toLower)
 import Data.Functor (($>))
-import Data.Maybe (isNothing, mapMaybe)
+import Data.Maybe (isJust, isNothing, mapMaybe)
 import Simplex.Messaging.Agent.Store.Shared
 import System.Exit (exitFailure)
 import System.IO (hFlush, stdout)
@@ -37,7 +37,7 @@ data DBMigrate = DBMigrate
   { initialize :: IO (),
     getCurrent :: IO [Migration],
     run :: MigrationsToRun -> IO (),
-    backup :: IO ()
+    backup :: Maybe (IO ())
   }
 
 sharedMigrateSchema :: DBMigrate -> Bool -> [Migration] -> MigrationConfirmation -> IO (Either MigrationError ())
@@ -54,20 +54,20 @@ sharedMigrateSchema dbm dbNew' migrations confirmMigrations = do
       | otherwise -> case confirmMigrations of
           MCYesUp -> runWithBackup ms
           MCYesUpDown -> runWithBackup ms
-          MCConsole -> confirm err >> runWithBackup ms
+          MCConsole -> confirm' err >> runWithBackup ms
           MCError -> pure $ Left err
       where
         err = MEUpgrade $ map upMigration ums -- "The app has a newer version than the database.\nConfirm to back up and upgrade using these migrations: " <> intercalate ", " (map name ums)
     Right ms@(MTRDown dms) -> case confirmMigrations of
       MCYesUpDown -> runWithBackup ms
-      MCConsole -> confirm err >> runWithBackup ms
+      MCConsole -> confirm' err >> runWithBackup ms
       MCYesUp -> pure $ Left err
       MCError -> pure $ Left err
       where
         err = MEDowngrade $ map downName dms
   where
-    runWithBackup ms = backup dbm >> run dbm ms $> Right ()
-    confirm err = confirmOrExit $ migrationErrorDescription err
+    runWithBackup ms = sequence (backup dbm) >> run dbm ms $> Right ()
+    confirm' err = confirmOrExit $ migrationErrorDescription (isJust $ backup dbm) err
 
 confirmOrExit :: String -> IO ()
 confirmOrExit s = do

src/Simplex/Messaging/Agent/Store/Postgres.hs

@@ -8,6 +8,7 @@ module Simplex.Messaging.Agent.Store.Postgres
   ( DBOpts (..),
     Migrations.getCurrentMigrations,
     checkSchemaExists,
+    migrateDBSchema,
     createDBStore,
     closeDBStore,
     reopenDBStore,
@@ -30,33 +31,36 @@ import Simplex.Messaging.Agent.Store.Migrations (DBMigrate (..), sharedMigrateSc
 import qualified Simplex.Messaging.Agent.Store.Postgres.Migrations as Migrations
 import Simplex.Messaging.Agent.Store.Postgres.Common
 import qualified Simplex.Messaging.Agent.Store.Postgres.DB as DB
-import Simplex.Messaging.Agent.Store.Shared (Migration (..), MigrationConfirmation (..), MigrationError (..))
+import Simplex.Messaging.Agent.Store.Shared (Migration (..), MigrationConfig (..), MigrationError (..))
 import Simplex.Messaging.Util (ifM, safeDecodeUtf8)
 import System.Exit (exitFailure)
 
 -- | Create a new Postgres DBStore with the given connection string, schema name and migrations.
 -- If passed schema does not exist in connectInfo database, it will be created.
 -- Applies necessary migrations to schema.
-createDBStore :: DBOpts -> [Migration] -> MigrationConfirmation -> IO (Either MigrationError DBStore)
-createDBStore opts migrations confirmMigrations = do
+createDBStore :: DBOpts -> [Migration] -> MigrationConfig -> IO (Either MigrationError DBStore)
+createDBStore opts migrations migrationConfig = do
   st <- connectPostgresStore opts
-  r <- migrateSchema st `onException` closeDBStore st
+  r <- migrateDBSchema st opts Nothing migrations migrationConfig `onException` closeDBStore st
   case r of
     Right () -> pure $ Right st
     Left e -> closeDBStore st $> Left e
-  where
-    migrateSchema st =
-      let initialize = Migrations.initialize st
-          getCurrent = withTransaction st Migrations.getCurrentMigrations
-          dbm = DBMigrate {initialize, getCurrent, run = Migrations.run st, backup = pure ()}
-       in sharedMigrateSchema dbm (dbNew st) migrations confirmMigrations
+
+migrateDBSchema :: DBStore -> DBOpts -> Maybe Query -> [Migration] -> MigrationConfig -> IO (Either MigrationError ())
+migrateDBSchema st _opts migrationsTable migrations MigrationConfig {confirm} =
+  let initialize = Migrations.initialize st migrationsTable
+      getCurrent = withTransaction st $ Migrations.getCurrentMigrations migrationsTable
+      run = Migrations.run st migrationsTable
+      dbm = DBMigrate {initialize, getCurrent, run, backup = Nothing}
+   in sharedMigrateSchema dbm (dbNew st) migrations confirm
 
 connectPostgresStore :: DBOpts -> IO DBStore
 connectPostgresStore DBOpts {connstr, schema, poolSize, createSchema} = do
   dbPriorityPool <- newDBStorePool poolSize
   dbPool <- newDBStorePool poolSize
   dbClosed <- newTVarIO True
-  let st = DBStore {dbConnstr = connstr, dbSchema = schema, dbPoolSize = fromIntegral poolSize, dbPriorityPool, dbPool, dbNew = False, dbClosed}
+  let dbConnect = fst <$> connectDB connstr schema False
+      st = DBStore {dbConnstr = connstr, dbSchema = schema, dbPoolSize = fromIntegral poolSize, dbPriorityPool, dbPool, dbConnect, dbNew = False, dbClosed}
   dbNew <- connectStore st createSchema
   pure st {dbNew}
 

src/Simplex/Messaging/Agent/Store/Postgres/Common.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.Common
@@ -14,13 +15,17 @@ module Simplex.Messaging.Agent.Store.Postgres.Common
     withTransaction,
     withTransaction',
     withTransactionPriority,
+    withSavepoint,
   )
 where
 
+import Control.Monad (void)
 import Control.Concurrent.MVar
 import Control.Concurrent.STM
-import Control.Exception (bracket)
+import qualified Control.Exception as E
+import Data.Bitraversable (bimapM)
 import Data.ByteString (ByteString)
+import Data.Functor (($>))
 import qualified Database.PostgreSQL.Simple as PSQL
 import Numeric.Natural (Natural)
 import Simplex.Messaging.Agent.Store.Postgres.Options
@@ -32,11 +37,7 @@ data DBStore = DBStore
     dbPoolSize :: Int,
     dbPriorityPool :: DBStorePool,
     dbPool :: DBStorePool,
-    -- dbPoolSize :: Int,
-    -- dbPool :: TBQueue PSQL.Connection,
-    -- -- MVar is needed for fair pool distribution, without STM retry contention.
-    -- -- Only one thread can be blocked on STM read.
-    -- dbSem :: MVar (),
+    dbConnect :: IO PSQL.Connection,
     dbClosed :: TVar Bool,
     dbNew :: Bool
   }
@@ -55,15 +56,23 @@ data DBStorePool = DBStorePool
   }
 
 withConnectionPriority :: DBStore -> Bool -> (PSQL.Connection -> IO a) -> IO a
-withConnectionPriority DBStore {dbPriorityPool, dbPool} priority =
-  withConnectionPool $ if priority then dbPriorityPool else dbPool
+withConnectionPriority DBStore {dbPriorityPool, dbPool, dbConnect} priority =
+  withConnectionPool (if priority then dbPriorityPool else dbPool) dbConnect
 {-# INLINE withConnectionPriority #-}
 
-withConnectionPool :: DBStorePool -> (PSQL.Connection -> IO a) -> IO a
-withConnectionPool DBStorePool {dbPoolConns, dbSem} =
-  bracket
-    (withMVar dbSem $ \_ -> atomically $ readTBQueue dbPoolConns)
-    (atomically . writeTBQueue dbPoolConns)
+withConnectionPool :: DBStorePool -> IO PSQL.Connection -> (PSQL.Connection -> IO a) -> IO a
+withConnectionPool DBStorePool {dbPoolConns, dbSem} dbConnect action =
+  E.mask $ \restore -> do
+    conn <- withMVar dbSem $ \_ -> atomically $ readTBQueue dbPoolConns
+    r <- restore (action conn) `E.onException` reset conn
+    atomically $ writeTBQueue dbPoolConns conn
+    pure r
+  where
+    reset conn = do
+      conn' <- E.try dbConnect >>= \case
+        Right conn' -> PSQL.close conn >> pure conn'
+        Left (_ :: E.SomeException) -> pure conn
+      atomically $ writeTBQueue dbPoolConns conn'
 
 withConnection :: DBStore -> (PSQL.Connection -> IO a) -> IO a
 withConnection st = withConnectionPriority st False
@@ -86,3 +95,14 @@ withTransactionPriority :: DBStore -> Bool -> (PSQL.Connection -> IO a) -> IO a
 withTransactionPriority st priority action = withConnectionPriority st priority transaction
   where
     transaction conn = PSQL.withTransaction conn $ action conn
+
+-- Execute an action within a savepoint.
+-- On success, releases the savepoint. On error, rolls back to the savepoint
+-- to restore the transaction to a usable state before returning the error.
+withSavepoint :: PSQL.Connection -> PSQL.Query -> IO a -> IO (Either PSQL.SqlError a)
+withSavepoint db name action = do
+  void $ PSQL.execute_ db $ "SAVEPOINT " <> name
+  E.try action
+    >>= bimapM
+      (PSQL.execute_ db ("ROLLBACK TO SAVEPOINT " <> name) $>)
+      (PSQL.execute_ db ("RELEASE SAVEPOINT " <> name) $>)

src/Simplex/Messaging/Agent/Store/Postgres/DB.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.DB
@@ -6,6 +7,7 @@ module Simplex.Messaging.Agent.Store.Postgres.DB
     PSQL.Connection,
     FromField (..),
     ToField (..),
+    SQLError,
     PSQL.connect,
     PSQL.close,
     execute,
@@ -20,21 +22,24 @@ where
 
 import qualified Control.Exception as E
 import Control.Monad (void)
+import qualified Data.ByteString as B
 import Data.ByteString.Char8 (ByteString)
-import qualified Data.ByteString.Char8 as B
 import Data.Int (Int64)
 import Data.Text (Text)
 import Data.Text.Encoding (decodeUtf8)
 import Data.Typeable (Typeable)
 import Data.Word (Word16, Word32)
-import Database.PostgreSQL.Simple (ResultError (..), SqlError (..))
+import Database.PostgreSQL.Simple (Connection, ResultError (..), SqlError (..), FromRow, ToRow)
 import qualified Database.PostgreSQL.Simple as PSQL
 import Database.PostgreSQL.Simple.FromField (Field (..), FieldParser, FromField (..), returnError)
 import Database.PostgreSQL.Simple.ToField (ToField (..))
 import Database.PostgreSQL.Simple.TypeInfo.Static (textOid, varcharOid)
+import Database.PostgreSQL.Simple.Types (Query (..))
 
 newtype BoolInt = BI {unBI :: Bool}
 
+type SQLError = SqlError
+
 instance FromField BoolInt where
   fromField field dat = BI . (/= (0 :: Int)) <$> fromField field dat
   {-# INLINE fromField #-}
@@ -43,49 +48,29 @@ instance ToField BoolInt where
   toField (BI b) = toField ((if b then 1 else 0) :: Int)
   {-# INLINE toField #-}
 
-execute :: PSQL.ToRow q => PSQL.Connection -> PSQL.Query -> q -> IO ()
-execute db q qs = withLoggedErrors q $ void $ PSQL.execute db q qs
+execute :: ToRow q => PSQL.Connection -> Query -> q -> IO ()
+execute db q qs = void $ PSQL.execute db q qs `E.catch` addSql q
 {-# INLINE execute #-}
 
-execute_ :: PSQL.Connection -> PSQL.Query -> IO ()
-execute_ db q = withLoggedErrors q $ void $ PSQL.execute_ db q
+execute_ :: PSQL.Connection -> Query -> IO ()
+execute_ db q = void $ PSQL.execute_ db q `E.catch` addSql q
 {-# INLINE execute_ #-}
 
-executeMany :: PSQL.ToRow q => PSQL.Connection -> PSQL.Query -> [q] -> IO ()
-executeMany db q qs = withLoggedErrors q $ void $ PSQL.executeMany db q qs
+executeMany :: ToRow q => PSQL.Connection -> Query -> [q] -> IO ()
+executeMany db q qs = void $ PSQL.executeMany db q qs `E.catch` addSql q
 {-# INLINE executeMany #-}
 
-query :: (PSQL.ToRow q, PSQL.FromRow r) => PSQL.Connection -> PSQL.Query -> q -> IO [r]
-query db q qs = withLoggedErrors q $ PSQL.query db q qs
+query :: (ToRow q, FromRow r) => PSQL.Connection -> Query -> q -> IO [r]
+query db q qs = PSQL.query db q qs `E.catch` addSql q
 {-# INLINE query #-}
 
-query_ :: PSQL.FromRow r => PSQL.Connection -> PSQL.Query -> IO [r]
-query_ db q = withLoggedErrors q $ PSQL.query_ db q
+query_ :: FromRow r => Connection -> Query -> IO [r]
+query_ db q = PSQL.query_ db q `E.catch` addSql q
 {-# INLINE query_ #-}
 
-withLoggedErrors :: Show q => q -> IO a -> IO a
-withLoggedErrors q action =
-  action
-    `E.catch` (\(e :: SqlError) -> logSqlErrorAndRethrow e)
-    `E.catch`
-      (\(e :: E.SomeException) ->
-        case E.fromException e :: Maybe SqlError of
-          Just sqlErr -> E.throwIO sqlErr -- rethrow SqlError without logging
-          Nothing -> logGenericErrorAndRethrow e
-      )
-  where
-    logSqlErrorAndRethrow :: SqlError -> IO a
-    logSqlErrorAndRethrow e = do
-      putStrLn "Caught SqlError"
-      putStrLn $ "Message: " <> B.unpack (sqlErrorMsg e)
-      putStrLn $ "SQL State: " <> B.unpack (sqlState e)
-      putStrLn $ "Query: " <> show q
-      E.throwIO e
-    logGenericErrorAndRethrow :: E.SomeException -> IO a
-    logGenericErrorAndRethrow e = do
-      putStrLn $ "Caught generic exception: " <> show e
-      putStrLn $ "Query: " <> show q
-      E.throwIO e
+addSql :: Query -> SqlError -> IO r
+addSql q e@SqlError {sqlErrorHint = hint} =
+  E.throwIO e {sqlErrorHint = if B.null hint then fromQuery q else hint <> ", " <> fromQuery q}
 
 -- orphan instances
 

src/Simplex/Messaging/Agent/Store/Postgres/Migrations.hs

@@ -14,55 +14,50 @@ where
 import Control.Exception (throwIO)
 import Control.Monad (void)
 import qualified Data.ByteString.Char8 as B
+import Data.Maybe (fromMaybe)
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import Data.Time.Clock (getCurrentTime)
 import qualified Database.PostgreSQL.LibPQ as LibPQ
-import Database.PostgreSQL.Simple (Only (..))
+import Database.PostgreSQL.Simple (Only (..), Query)
 import qualified Database.PostgreSQL.Simple as PSQL
 import Database.PostgreSQL.Simple.Internal (Connection (..))
-import Database.PostgreSQL.Simple.SqlQQ (sql)
 import Simplex.Messaging.Agent.Store.Postgres.Common
 import Simplex.Messaging.Agent.Store.Shared
 import Simplex.Messaging.Util (($>>=))
 import UnliftIO.MVar
 
-initialize :: DBStore -> IO ()
-initialize st = withTransaction' st $ \db ->
-  void $
-    PSQL.execute_
-      db
-      [sql|
-      CREATE TABLE IF NOT EXISTS migrations (
-        name TEXT NOT NULL,
-        ts TIMESTAMP NOT NULL,
-        down TEXT,
-        PRIMARY KEY (name)
-      )
-    |]
+initialize :: DBStore -> Maybe Query -> IO ()
+initialize st migrationsTable = withTransaction' st $ \db ->
+  void $ PSQL.execute_ db $
+    "CREATE TABLE IF NOT EXISTS "
+      <> fromMaybe "migrations" migrationsTable
+      <> " (name TEXT NOT NULL PRIMARY KEY, ts TIMESTAMP NOT NULL, down TEXT)"
 
-run :: DBStore -> MigrationsToRun -> IO ()
-run st = \case
+run :: DBStore -> Maybe Query -> MigrationsToRun -> IO ()
+run st migrationsTable = \case
   MTRUp [] -> pure ()
   MTRUp ms -> mapM_ runUp ms
   MTRDown ms -> mapM_ runDown $ reverse ms
   MTRNone -> pure ()
   where
+    table = fromMaybe "migrations" migrationsTable
     runUp Migration {name, up, down} = withTransaction' st $ \db -> do
       insert db
       execSQL db up
       where
-        insert db = void $ PSQL.execute db "INSERT INTO migrations (name, down, ts) VALUES (?,?,?)" . (name,down,) =<< getCurrentTime
+        insert db = void $ PSQL.execute db ("INSERT INTO " <> table <> " (name, down, ts) VALUES (?,?,?)") . (name,down,) =<< getCurrentTime
     runDown DownMigration {downName, downQuery} = withTransaction' st $ \db -> do
       execSQL db downQuery
-      void $ PSQL.execute db "DELETE FROM migrations WHERE name = ?" (Only downName)
+      void $ PSQL.execute db ("DELETE FROM " <> table <> " WHERE name = ?") (Only downName)
     execSQL db query =
       withMVar (connectionHandle db) $ \pqConn ->
         LibPQ.exec pqConn (TE.encodeUtf8 query) $>>= LibPQ.resultErrorMessage >>= \case
           Just e | not (B.null e) -> throwIO $ userError $ B.unpack e
           _ -> pure ()
 
-getCurrentMigrations :: PSQL.Connection -> IO [Migration]
-getCurrentMigrations db = map toMigration <$> PSQL.query_ db "SELECT name, down FROM migrations ORDER BY name ASC;"
+getCurrentMigrations :: Maybe Query -> PSQL.Connection -> IO [Migration]
+getCurrentMigrations migrationsTable db = map toMigration <$> PSQL.query_ db ("SELECT name, down FROM " <> table <> " ORDER BY name ASC;")
   where
+    table = fromMaybe "migrations" migrationsTable
     toMigration (name, down) = Migration {name, up = T.pack "", down}

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/App.hs

@@ -8,6 +8,9 @@ import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20241210_initial
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250203_msg_bodies
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250322_short_links
 import Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250702_conn_invitations_remove_cascade_delete
+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.Shared (Migration (..))
 
 schemaMigrations :: [(String, Text, Maybe Text)]
@@ -15,7 +18,10 @@ schemaMigrations =
   [ ("20241210_initial", m20241210_initial, Nothing),
     ("20250203_msg_bodies", m20250203_msg_bodies, Just down_m20250203_msg_bodies),
     ("20250322_short_links", m20250322_short_links, Just down_m20250322_short_links),
-    ("20250702_conn_invitations_remove_cascade_delete", m20250702_conn_invitations_remove_cascade_delete, Just down_m20250702_conn_invitations_remove_cascade_delete)
+    ("20250702_conn_invitations_remove_cascade_delete", m20250702_conn_invitations_remove_cascade_delete, Just down_m20250702_conn_invitations_remove_cascade_delete),
+    ("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)
   ]
 
 -- | The list of migrations in ascending order by date

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20241210_initial.hs

@@ -1,15 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20241210_initial where
 
 import Data.Text (Text)
-import qualified Data.Text as T
 import Text.RawString.QQ (r)
 
 m20241210_initial :: Text
 m20241210_initial =
-  T.pack
-    [r|
+  [r|
 CREATE TABLE users(
   user_id BIGINT PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
   deleted SMALLINT NOT NULL DEFAULT 0

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20250203_msg_bodies.hs

@@ -1,15 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250203_msg_bodies where
 
 import Data.Text (Text)
-import qualified Data.Text as T
 import Text.RawString.QQ (r)
 
 m20250203_msg_bodies :: Text
 m20250203_msg_bodies =
-  T.pack
-    [r|
+  [r|
 ALTER TABLE snd_messages ADD COLUMN msg_encrypt_key BYTEA;
 ALTER TABLE snd_messages ADD COLUMN padded_msg_len BIGINT;
 
@@ -25,8 +24,7 @@ CREATE INDEX idx_snd_messages_snd_message_body_id ON snd_messages(snd_message_bo
 
 down_m20250203_msg_bodies :: Text
 down_m20250203_msg_bodies =
-  T.pack
-    [r|
+  [r|
 DROP INDEX idx_snd_messages_snd_message_body_id;
 ALTER TABLE snd_messages DROP COLUMN snd_message_body_id;
 DROP TABLE snd_message_bodies;

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20250322_short_links.hs

@@ -1,15 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250322_short_links where
 
 import Data.Text (Text)
-import qualified Data.Text as T
 import Text.RawString.QQ (r)
 
 m20250322_short_links :: Text
 m20250322_short_links =
-  T.pack    
-    [r|
+  [r|
 ALTER TABLE rcv_queues ADD COLUMN link_id BYTEA;
 ALTER TABLE rcv_queues ADD COLUMN link_key BYTEA;
 ALTER TABLE rcv_queues ADD COLUMN link_priv_sig_key BYTEA;
@@ -42,8 +41,7 @@ CREATE UNIQUE INDEX idx_inv_short_links_link_id ON inv_short_links(host, port, l
 
 down_m20250322_short_links :: Text
 down_m20250322_short_links =
-  T.pack
-    [r|
+  [r|
 DROP INDEX idx_rcv_queues_link_id;
 ALTER TABLE rcv_queues DROP COLUMN link_id;
 ALTER TABLE rcv_queues DROP COLUMN link_key;

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20250702_conn_invitations_remove_cascade_delete.hs

@@ -1,15 +1,14 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes #-}
 
 module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20250702_conn_invitations_remove_cascade_delete where
 
 import Data.Text (Text)
-import qualified Data.Text as T
 import Text.RawString.QQ (r)
 
 m20250702_conn_invitations_remove_cascade_delete :: Text
 m20250702_conn_invitations_remove_cascade_delete =
-  T.pack
-    [r|
+  [r|
 ALTER TABLE conn_invitations DROP CONSTRAINT conn_invitations_contact_conn_id_fkey;
 
 ALTER TABLE conn_invitations ALTER COLUMN contact_conn_id DROP NOT NULL;
@@ -23,8 +22,7 @@ ALTER TABLE conn_invitations
 
 down_m20250702_conn_invitations_remove_cascade_delete :: Text
 down_m20250702_conn_invitations_remove_cascade_delete =
-  T.pack
-    [r|
+  [r|
 ALTER TABLE conn_invitations DROP CONSTRAINT conn_invitations_contact_conn_id_fkey;
 
 ALTER TABLE conn_invitations ALTER COLUMN contact_conn_id SET NOT NULL;

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20251009_queue_to_subscribe.hs

@@ -0,0 +1,21 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251009_queue_to_subscribe where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+m20251009_queue_to_subscribe :: Text
+m20251009_queue_to_subscribe =
+  [r|
+ALTER TABLE rcv_queues ADD COLUMN to_subscribe SMALLINT NOT NULL DEFAULT 0;
+CREATE INDEX idx_rcv_queues_to_subscribe ON rcv_queues(to_subscribe);
+|]
+
+down_m20251009_queue_to_subscribe :: Text
+down_m20251009_queue_to_subscribe =
+  [r|
+DROP INDEX idx_rcv_queues_to_subscribe;
+ALTER TABLE rcv_queues DROP COLUMN to_subscribe;
+|]

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20251010_client_notices.hs

@@ -0,0 +1,40 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251010_client_notices where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+m20251010_client_notices :: Text
+m20251010_client_notices =
+  [r|
+CREATE TABLE client_notices(
+  client_notice_id BIGINT PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+  protocol TEXT NOT NULL,
+  host TEXT NOT NULL,
+  port TEXT NOT NULL,
+  entity_id BYTEA NOT NULL,
+  server_key_hash BYTEA,
+  notice_ttl BIGINT,
+  created_at BIGINT NOT NULL,
+  updated_at BIGINT NOT NULL
+);
+
+CREATE UNIQUE INDEX idx_client_notices_entity ON client_notices(protocol, host, port, entity_id);
+
+ALTER TABLE rcv_queues ADD COLUMN client_notice_id BIGINT
+REFERENCES client_notices ON UPDATE RESTRICT ON DELETE SET NULL;
+
+CREATE INDEX idx_rcv_queues_client_notice_id ON rcv_queues(client_notice_id);
+|]
+
+down_m20251010_client_notices :: Text
+down_m20251010_client_notices =
+  [r|
+DROP INDEX idx_rcv_queues_client_notice_id;
+ALTER TABLE rcv_queues DROP COLUMN client_notice_id;
+
+DROP INDEX idx_client_notices_entity;
+DROP TABLE client_notices;
+|]

src/Simplex/Messaging/Agent/Store/Postgres/Migrations/M20251230_strict_tables.hs

@@ -0,0 +1,66 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.Postgres.Migrations.M20251230_strict_tables where
+
+import Data.Text (Text)
+import Text.RawString.QQ (r)
+
+m20251230_strict_tables :: Text
+m20251230_strict_tables =
+  isValidText
+    <> [r|
+DELETE FROM ntf_tokens
+WHERE NOT simplex_is_valid_text(ntf_mode);
+
+ALTER TABLE ntf_tokens
+  ALTER COLUMN device_token TYPE BYTEA USING device_token::BYTEA,
+  ALTER COLUMN ntf_mode TYPE TEXT USING ntf_mode::TEXT;
+
+UPDATE ntf_subscriptions
+SET ntf_sub_action = NULL
+WHERE NOT simplex_is_valid_text(ntf_sub_action);
+
+UPDATE ntf_subscriptions
+SET ntf_sub_smp_action = NULL
+WHERE NOT simplex_is_valid_text(ntf_sub_smp_action);
+
+ALTER TABLE ntf_subscriptions
+  ALTER COLUMN ntf_sub_action TYPE TEXT USING ntf_sub_action::TEXT,
+  ALTER COLUMN ntf_sub_smp_action TYPE TEXT USING ntf_sub_smp_action::TEXT;
+
+DROP FUNCTION simplex_is_valid_text(BYTEA);
+|]
+
+down_m20251230_strict_tables :: Text
+down_m20251230_strict_tables =
+  isValidText
+    <> [r|
+DELETE FROM ntf_tokens
+WHERE NOT simplex_is_valid_text(device_token);
+
+ALTER TABLE ntf_tokens
+  ALTER COLUMN device_token TYPE TEXT USING device_token::TEXT,
+  ALTER COLUMN ntf_mode TYPE BYTEA USING ntf_mode::BYTEA;
+
+ALTER TABLE ntf_subscriptions
+  ALTER COLUMN ntf_sub_action TYPE BYTEA USING ntf_sub_action::BYTEA,
+  ALTER COLUMN ntf_sub_smp_action TYPE BYTEA USING ntf_sub_smp_action::BYTEA;
+
+DROP FUNCTION simplex_is_valid_text(BYTEA);
+|]
+
+isValidText :: Text
+isValidText =
+  [r|
+CREATE FUNCTION simplex_is_valid_text(b BYTEA)
+RETURNS BOOLEAN
+LANGUAGE plpgsql AS $$
+BEGIN
+    PERFORM b::TEXT;
+    RETURN TRUE;
+EXCEPTION
+    WHEN OTHERS THEN RETURN FALSE;
+END;
+$$;
+|]

src/Simplex/Messaging/Agent/Store/Postgres/Options.hs

@@ -1,4 +1,6 @@
-module Simplex.Messaging.Agent.Store.Postgres.Options where
+module Simplex.Messaging.Agent.Store.Postgres.Options
+  ( DBOpts (..),
+  ) where
 
 import Data.ByteString (ByteString)
 import Numeric.Natural

src/Simplex/Messaging/Agent/Store/SQLite.hs

@@ -27,6 +27,7 @@
 module Simplex.Messaging.Agent.Store.SQLite
   ( DBOpts (..),
     Migrations.getCurrentMigrations,
+    migrateDBSchema,
     createDBStore,
     closeDBStore,
     reopenDBStore,
@@ -41,6 +42,9 @@ module Simplex.Messaging.Agent.Store.SQLite
   )
 where
 
+import Control.Concurrent.MVar
+import Control.Concurrent.STM
+import Control.Exception (bracketOnError, onException, throwIO)
 import Control.Monad
 import Data.ByteArray (ScrubbedBytes)
 import qualified Data.ByteArray as BA
@@ -57,55 +61,57 @@ import Simplex.Messaging.Agent.Store.Migrations (DBMigrate (..), sharedMigrateSc
 import qualified Simplex.Messaging.Agent.Store.SQLite.Migrations as Migrations
 import Simplex.Messaging.Agent.Store.SQLite.Common
 import qualified Simplex.Messaging.Agent.Store.SQLite.DB as DB
-import Simplex.Messaging.Agent.Store.Shared (Migration (..), MigrationConfirmation (..), MigrationError (..))
+import Simplex.Messaging.Agent.Store.SQLite.Util
+import Simplex.Messaging.Agent.Store.Shared (Migration (..), MigrationConfig (..), MigrationError (..))
 import Simplex.Messaging.Util (ifM, safeDecodeUtf8)
 import System.Directory (copyFile, createDirectoryIfMissing, doesFileExist)
-import System.FilePath (takeDirectory)
-import UnliftIO.Exception (bracketOnError, onException)
-import UnliftIO.MVar
-import UnliftIO.STM
+import System.FilePath (takeDirectory, takeFileName, (</>))
 
 -- * SQLite Store implementation
 
-createDBStore :: DBOpts -> [Migration] -> MigrationConfirmation -> IO (Either MigrationError DBStore)
-createDBStore DBOpts {dbFilePath, dbKey, keepKey, track, vacuum} migrations confirmMigrations = do
+createDBStore :: DBOpts -> [Migration] -> MigrationConfig -> IO (Either MigrationError DBStore)
+createDBStore opts@DBOpts {dbFilePath} migrations migrationConfig = do
   let dbDir = takeDirectory dbFilePath
   createDirectoryIfMissing True dbDir
-  st <- connectSQLiteStore dbFilePath dbKey keepKey track
-  r <- migrateSchema st `onException` closeDBStore st
+  st <- connectSQLiteStore opts
+  r <- migrateDBSchema st opts Nothing migrations migrationConfig `onException` closeDBStore st
   case r of
     Right () -> pure $ Right st
     Left e -> closeDBStore st $> Left e
   where
-    migrateSchema st =
-      let initialize = Migrations.initialize st
-          getCurrent = withTransaction st Migrations.getCurrentMigrations
-          run = Migrations.run st vacuum
-          backup = copyFile dbFilePath (dbFilePath <> ".bak")
-          dbm = DBMigrate {initialize, getCurrent, run, backup}
-       in sharedMigrateSchema dbm (dbNew st) migrations confirmMigrations
 
-connectSQLiteStore :: FilePath -> ScrubbedBytes -> Bool -> DB.TrackQueries -> IO DBStore
-connectSQLiteStore dbFilePath key keepKey track = do
+migrateDBSchema :: DBStore -> DBOpts -> Maybe Query -> [Migration] -> MigrationConfig -> IO (Either MigrationError ())
+migrateDBSchema st DBOpts {dbFilePath, vacuum} migrationsTable migrations MigrationConfig {confirm, backupPath} =
+  let initialize = Migrations.initialize st migrationsTable
+      getCurrent = withTransaction st $ Migrations.getCurrentMigrations migrationsTable
+      run = Migrations.run st migrationsTable vacuum
+      backup = mkBackup <$> backupPath
+      mkBackup bp =
+        let f = if null bp then dbFilePath else bp </> takeFileName dbFilePath
+          in copyFile dbFilePath $ f <> ".bak"
+      dbm = DBMigrate {initialize, getCurrent, run, backup}
+   in sharedMigrateSchema dbm (dbNew st) migrations confirm
+
+connectSQLiteStore :: DBOpts -> IO DBStore
+connectSQLiteStore DBOpts {dbFilePath, dbFunctions, dbKey = key, keepKey, track} = do
   dbNew <- not <$> doesFileExist dbFilePath
-  dbConn <- dbBusyLoop (connectDB dbFilePath key track)
+  dbConn <- dbBusyLoop $ connectDB dbFilePath dbFunctions key track
   dbConnection <- newMVar dbConn
   dbKey <- newTVarIO $! storeKey key keepKey
   dbClosed <- newTVarIO False
   dbSem <- newTVarIO 0
-  pure DBStore {dbFilePath, dbKey, dbSem, dbConnection, dbNew, dbClosed}
+  pure DBStore {dbFilePath, dbFunctions, dbKey, dbSem, dbConnection, dbNew, dbClosed}
 
-connectDB :: FilePath -> ScrubbedBytes -> DB.TrackQueries -> IO DB.Connection
-connectDB path key track = do
+connectDB :: FilePath -> [SQLiteFuncDef] -> ScrubbedBytes -> DB.TrackQueries -> IO DB.Connection
+connectDB path functions key track = do
   db <- DB.open path track
   prepare db `onException` DB.close db
   -- _printPragmas db path
   pure db
   where
     prepare db = do
-      let exec = SQLite3.exec $ SQL.connectionHandle $ DB.conn db
-      unless (BA.null key) . exec $ "PRAGMA key = " <> keyString key <> ";"
-      exec . fromQuery $
+      unless (BA.null key) . SQLite3.exec db' $ "PRAGMA key = " <> keyString key <> ";"
+      SQLite3.exec db' . fromQuery $
         [sql|
           PRAGMA busy_timeout = 100;
           PRAGMA foreign_keys = ON;
@@ -113,6 +119,13 @@ connectDB path key track = do
           PRAGMA secure_delete = ON;
           PRAGMA auto_vacuum = FULL;
         |]
+      mapM_ addFunction functions
+      where
+        db' = SQL.connectionHandle $ DB.conn db
+        addFunction SQLiteFuncDef {funcName, argCount, funcPtrs} =
+          either (throwIO . userError . show) pure =<< case funcPtrs of
+            SQLiteFuncPtr isDet funcPtr -> createStaticFunction db' funcName argCount isDet funcPtr
+            SQLiteAggrPtrs stepPtr finalPtr -> createStaticAggregate db' funcName argCount stepPtr finalPtr
 
 closeDBStore :: DBStore -> IO ()
 closeDBStore st@DBStore {dbClosed} =
@@ -126,12 +139,12 @@ openSQLiteStore st@DBStore {dbClosed} key keepKey =
   ifM (readTVarIO dbClosed) (openSQLiteStore_ st key keepKey) (putStrLn "openSQLiteStore: already opened")
 
 openSQLiteStore_ :: DBStore -> ScrubbedBytes -> Bool -> IO ()
-openSQLiteStore_ DBStore {dbConnection, dbFilePath, dbKey, dbClosed} key keepKey =
+openSQLiteStore_ DBStore {dbConnection, dbFilePath, dbFunctions, dbKey, dbClosed} key keepKey =
   bracketOnError
     (takeMVar dbConnection)
     (tryPutMVar dbConnection)
     $ \DB.Connection {slow, track} -> do
-      DB.Connection {conn} <- connectDB dbFilePath key track
+      DB.Connection {conn} <- connectDB dbFilePath dbFunctions key track
       atomically $ do
         writeTVar dbClosed False
         writeTVar dbKey $! storeKey key keepKey

src/Simplex/Messaging/Agent/Store/SQLite/Common.hs

@@ -6,11 +6,14 @@
 module Simplex.Messaging.Agent.Store.SQLite.Common
   ( DBStore (..),
     DBOpts (..),
+    SQLiteFuncDef (..),
+    SQLiteFuncPtrs (..),
     withConnection,
     withConnection',
     withTransaction,
     withTransaction',
     withTransactionPriority,
+    withSavepoint,
     dbBusyLoop,
     storeKey,
   )
@@ -20,9 +23,13 @@ import Control.Concurrent (threadDelay)
 import Control.Concurrent.STM (retry)
 import Data.ByteArray (ScrubbedBytes)
 import qualified Data.ByteArray as BA
+import Data.ByteString (ByteString)
 import Database.SQLite.Simple (SQLError)
 import qualified Database.SQLite.Simple as SQL
+import Database.SQLite3.Bindings
+import Foreign.Ptr
 import qualified Simplex.Messaging.Agent.Store.SQLite.DB as DB
+import Simplex.Messaging.Agent.Store.SQLite.Util
 import Simplex.Messaging.Util (ifM, unlessM)
 import qualified UnliftIO.Exception as E
 import UnliftIO.MVar
@@ -33,6 +40,7 @@ storeKey key keepKey = if keepKey || BA.null key then Just key else Nothing
 
 data DBStore = DBStore
   { dbFilePath :: FilePath,
+    dbFunctions :: [SQLiteFuncDef],
     dbKey :: TVar (Maybe ScrubbedBytes),
     dbSem :: TVar Int,
     dbConnection :: MVar DB.Connection,
@@ -42,12 +50,25 @@ data DBStore = DBStore
 
 data DBOpts = DBOpts
   { dbFilePath :: FilePath,
+    dbFunctions :: [SQLiteFuncDef],
     dbKey :: ScrubbedBytes,
     keepKey :: Bool,
     vacuum :: Bool,
     track :: DB.TrackQueries
   }
 
+-- e.g. `SQLiteFuncDef "func_name" 2 (SQLiteFuncPtr True func)`
+-- or   `SQLiteFuncDef "aggr_name" 3 (SQLiteAggrPtrs step final)`
+data SQLiteFuncDef = SQLiteFuncDef
+  { funcName :: ByteString,
+    argCount :: CArgCount,
+    funcPtrs :: SQLiteFuncPtrs
+  }
+
+data SQLiteFuncPtrs
+  = SQLiteFuncPtr {deterministic :: Bool, funcPtr :: FunPtr SQLiteFunc}
+  | SQLiteAggrPtrs {stepPtr :: FunPtr SQLiteFunc, finalPtr :: FunPtr SQLiteFuncFinal}
+
 withConnectionPriority :: DBStore -> Bool -> (DB.Connection -> IO a) -> IO a
 withConnectionPriority DBStore {dbSem, dbConnection} priority action
   | priority = E.bracket_ signal release $ withMVar dbConnection action
@@ -77,6 +98,12 @@ withTransactionPriority st priority action = withConnectionPriority st priority
   where
     transaction db@DB.Connection {conn} = SQL.withImmediateTransaction conn $ action db
 
+-- No-op for SQLite, just tries the action.
+-- This provides a consistent interface with the PostgreSQL version.
+withSavepoint :: DB.Connection -> SQL.Query -> IO a -> IO (Either SQLError a)
+withSavepoint _ _ = E.try
+{-# INLINE withSavepoint #-}
+
 dbBusyLoop :: forall a. IO a -> IO a
 dbBusyLoop action = loop 500 3000000
   where

src/Simplex/Messaging/Agent/Store/SQLite/DB.hs

@@ -14,6 +14,7 @@ module Simplex.Messaging.Agent.Store.SQLite.DB
     TrackQueries (..),
     FromField (..),
     ToField (..),
+    SQLError,
     open,
     close,
     execute,
@@ -38,7 +39,7 @@ import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Time (diffUTCTime, getCurrentTime)
 import Data.Typeable (Typeable)
-import Database.SQLite.Simple (FromRow, ResultError (..), Query, SQLData (..), ToRow)
+import Database.SQLite.Simple (FromRow, ResultError (..), Query, SQLData (..), SQLError, ToRow)
 import qualified Database.SQLite.Simple as SQL
 import Database.SQLite.Simple.FromField (FieldParser, FromField (..), returnError)
 import Database.SQLite.Simple.Internal (Field (..))
@@ -52,7 +53,7 @@ import Simplex.Messaging.Util (diffToMicroseconds, tshow)
 newtype BoolInt = BI {unBI :: Bool}
   deriving newtype (FromField, ToField)
 
-newtype Binary = Binary {fromBinary :: ByteString}
+newtype Binary a = Binary {fromBinary :: a}
   deriving newtype (FromField, ToField)
 
 data Connection = Connection

src/Simplex/Messaging/Agent/Store/SQLite/Migrations.hs

@@ -17,12 +17,12 @@ where
 import Control.Monad (forM_, when)
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.Map.Strict as M
+import Data.Maybe (fromMaybe)
 import Data.Text (Text)
 import Data.Text.Encoding (decodeLatin1)
 import Data.Time.Clock (getCurrentTime)
 import Database.SQLite.Simple (Only (..), Query (..))
 import qualified Database.SQLite.Simple as SQL
-import Database.SQLite.Simple.QQ (sql)
 import qualified Database.SQLite3 as SQLite3
 import Simplex.Messaging.Agent.Protocol (extraSMPServerHosts)
 import qualified Simplex.Messaging.Agent.Store.DB as DB
@@ -32,13 +32,16 @@ import Simplex.Messaging.Agent.Store.Shared
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Transport.Client (TransportHost)
 
-getCurrentMigrations :: DB.Connection -> IO [Migration]
-getCurrentMigrations DB.Connection {DB.conn} = map toMigration <$> SQL.query_ conn "SELECT name, down FROM migrations ORDER BY name ASC;"
+getCurrentMigrations :: Maybe Query -> DB.Connection -> IO [Migration]
+getCurrentMigrations migrationsTable DB.Connection {DB.conn} =
+  map toMigration
+    <$> SQL.query_ conn ("SELECT name, down FROM " <> table <> " ORDER BY name ASC;")
   where
+    table = fromMaybe "migrations" migrationsTable
     toMigration (name, down) = Migration {name, up = "", down}
 
-run :: DBStore -> Bool -> MigrationsToRun -> IO ()
-run st vacuum = \case
+run :: DBStore -> Maybe Query -> Bool -> MigrationsToRun -> IO ()
+run st migrationsTable vacuum = \case
   MTRUp [] -> pure ()
   MTRUp ms -> do
     mapM_ runUp ms
@@ -46,11 +49,12 @@ run st vacuum = \case
   MTRDown ms -> mapM_ runDown $ reverse ms
   MTRNone -> pure ()
   where
+    table = fromMaybe "migrations" migrationsTable
     runUp Migration {name, up, down} = withTransaction' st $ \db -> do
       when (name == "m20220811_onion_hosts") $ updateServers db
       insert db >> execSQL db up'
       where
-        insert db = SQL.execute db "INSERT INTO migrations (name, down, ts) VALUES (?,?,?)" . (name,down,) =<< getCurrentTime
+        insert db = SQL.execute db ("INSERT INTO " <> table <> " (name, down, ts) VALUES (?,?,?)") . (name,down,) =<< getCurrentTime
         up'
           | dbNew st && name == "m20230110_users" = fromQuery new_m20230110_users
           | otherwise = up
@@ -59,24 +63,19 @@ run st vacuum = \case
            in SQL.execute db "UPDATE servers SET host = ? WHERE host = ?" (hs, decodeLatin1 $ strEncode h)
     runDown DownMigration {downName, downQuery} = withTransaction' st $ \db -> do
       execSQL db downQuery
-      SQL.execute db "DELETE FROM migrations WHERE name = ?" (Only downName)
+      SQL.execute db ("DELETE FROM " <> table <> " WHERE name = ?") (Only downName)
     execSQL db = SQLite3.exec $ SQL.connectionHandle db
 
-initialize :: DBStore -> IO ()
-initialize st = withTransaction' st $ \db -> do
-  cs :: [Text] <- map fromOnly <$> SQL.query_ db "SELECT name FROM pragma_table_info('migrations')"
+initialize :: DBStore -> Maybe Query -> IO ()
+initialize st migrationsTable = withTransaction' st $ \db -> do
+  cs :: [Text] <- map fromOnly <$> SQL.query_ db ("SELECT name FROM pragma_table_info('" <> table <> "')")
   case cs of
     [] -> createMigrations db
-    _ -> when ("down" `notElem` cs) $ SQL.execute_ db "ALTER TABLE migrations ADD COLUMN down TEXT"
+    _ -> when ("down" `notElem` cs) $ SQL.execute_ db $ "ALTER TABLE " <> table <> " ADD COLUMN down TEXT"
   where
+    table = fromMaybe "migrations" migrationsTable
     createMigrations db =
-      SQL.execute_
-        db
-        [sql|
-          CREATE TABLE IF NOT EXISTS migrations (
-            name TEXT NOT NULL,
-            ts TEXT NOT NULL,
-            down TEXT,
-            PRIMARY KEY (name)
-          );
-        |]
+      SQL.execute_ db $
+        "CREATE TABLE IF NOT EXISTS "
+          <> table
+          <> " (name TEXT NOT NULL PRIMARY KEY, ts TEXT NOT NULL, down TEXT)"

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/App.hs

@@ -44,6 +44,9 @@ import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20241224_ratchet_e2e_snd
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250203_msg_bodies
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250322_short_links
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20250702_conn_invitations_remove_cascade_delete
+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.Shared (Migration (..))
 
 schemaMigrations :: [(String, Query, Maybe Query)]
@@ -87,7 +90,10 @@ schemaMigrations =
     ("m20241224_ratchet_e2e_snd_params", m20241224_ratchet_e2e_snd_params, Just down_m20241224_ratchet_e2e_snd_params),
     ("m20250203_msg_bodies", m20250203_msg_bodies, Just down_m20250203_msg_bodies),
     ("m20250322_short_links", m20250322_short_links, Just down_m20250322_short_links),
-    ("m20250702_conn_invitations_remove_cascade_delete", m20250702_conn_invitations_remove_cascade_delete, Just down_m20250702_conn_invitations_remove_cascade_delete)
+    ("m20250702_conn_invitations_remove_cascade_delete", m20250702_conn_invitations_remove_cascade_delete, Just down_m20250702_conn_invitations_remove_cascade_delete),
+    ("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)
   ]
 
 -- | The list of migrations in ascending order by date

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20220322_notifications.hs

@@ -19,7 +19,7 @@ CREATE TABLE ntf_servers (
 
 CREATE TABLE ntf_tokens (
   provider TEXT NOT NULL, -- apns
-  device_token TEXT NOT NULL, -- ! this field is mislabeled and is actually saved as binary
+  device_token TEXT NOT NULL,
   ntf_host TEXT NOT NULL,
   ntf_port TEXT NOT NULL,
   tkn_id BLOB, -- token ID assigned by notifications server

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20240624_snd_secure.hs

@@ -17,7 +17,7 @@ UPDATE sqlite_master
 SET sql = replace(sql, 'sender_key BLOB NOT NULL,', 'sender_key BLOB,')
 WHERE name = 'conn_confirmations' AND type = 'table';
 
-PRAGMA writable_schema=0;
+PRAGMA writable_schema=RESET;
 |]
 
 down_m20240624_snd_secure :: Query
@@ -32,5 +32,5 @@ UPDATE sqlite_master
 SET sql = replace(sql, 'sender_key BLOB,', 'sender_key BLOB NOT NULL,')
 WHERE name = 'conn_confirmations' AND type = 'table';
 
-PRAGMA writable_schema=0;
+PRAGMA writable_schema=RESET;
 |]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20250702_conn_invitations_remove_cascade_delete.hs

@@ -18,7 +18,7 @@ SET sql = replace(
           )
 WHERE name = 'conn_invitations' AND type = 'table';
 
-PRAGMA writable_schema=0;
+PRAGMA writable_schema=RESET;
 |]
 
 down_m20250702_conn_invitations_remove_cascade_delete :: Query
@@ -34,5 +34,5 @@ SET sql = replace(
           )
 WHERE name = 'conn_invitations' AND type = 'table';
 
-PRAGMA writable_schema=0;
+PRAGMA writable_schema=RESET;
 |]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20251009_queue_to_subscribe.hs

@@ -0,0 +1,20 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251009_queue_to_subscribe where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20251009_queue_to_subscribe :: Query
+m20251009_queue_to_subscribe =
+  [sql|
+ALTER TABLE rcv_queues ADD COLUMN to_subscribe INTEGER NOT NULL DEFAULT 0;
+CREATE INDEX idx_rcv_queues_to_subscribe ON rcv_queues(to_subscribe);
+|]
+
+down_m20251009_queue_to_subscribe :: Query
+down_m20251009_queue_to_subscribe =
+  [sql|
+DROP INDEX idx_rcv_queues_to_subscribe;
+ALTER TABLE rcv_queues DROP COLUMN to_subscribe;
+|]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20251010_client_notices.hs

@@ -0,0 +1,39 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251010_client_notices where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20251010_client_notices :: Query
+m20251010_client_notices =
+  [sql|
+CREATE TABLE client_notices(
+  client_notice_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  protocol TEXT NOT NULL,
+  host TEXT NOT NULL,
+  port TEXT NOT NULL,
+  entity_id BLOB NOT NULL,
+  server_key_hash BLOB,
+  notice_ttl INTEGER,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL
+);
+
+CREATE UNIQUE INDEX idx_client_notices_entity ON client_notices(protocol, host, port, entity_id);
+
+ALTER TABLE rcv_queues ADD COLUMN client_notice_id INTEGER
+REFERENCES client_notices ON UPDATE RESTRICT ON DELETE SET NULL;
+
+CREATE INDEX idx_rcv_queues_client_notice_id ON rcv_queues(client_notice_id);
+|]
+
+down_m20251010_client_notices :: Query
+down_m20251010_client_notices =
+  [sql|
+DROP INDEX idx_rcv_queues_client_notice_id;
+ALTER TABLE rcv_queues DROP COLUMN client_notice_id;
+
+DROP INDEX idx_client_notices_entity;
+DROP TABLE client_notices;
+|]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20251230_strict_tables.hs

@@ -0,0 +1,58 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20251230_strict_tables where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20251230_strict_tables :: Query
+m20251230_strict_tables =
+  [sql|
+UPDATE ntf_tokens SET ntf_mode = CAST(ntf_mode as TEXT);
+
+UPDATE ntf_subscriptions
+SET ntf_sub_action = CAST(ntf_sub_action as TEXT),
+    ntf_sub_smp_action = CAST(ntf_sub_smp_action as TEXT);
+
+PRAGMA writable_schema=1;
+
+UPDATE sqlite_master
+SET sql = CASE
+  WHEN LOWER(SUBSTR(sql, -15)) = ') without rowid' THEN sql || ', STRICT'
+  WHEN SUBSTR(sql, -1) = ')' THEN sql || ' STRICT'
+  ELSE sql
+END
+WHERE type = 'table' AND name != 'sqlite_sequence';
+
+UPDATE sqlite_master
+SET sql = replace(sql, 'device_token TEXT NOT NULL', 'device_token BLOB NOT NULL')
+WHERE type = 'table' AND name = 'ntf_tokens';
+
+PRAGMA writable_schema=RESET;
+|]
+
+down_m20251230_strict_tables :: Query
+down_m20251230_strict_tables =
+  [sql|
+PRAGMA writable_schema=1;
+
+UPDATE sqlite_master
+SET sql = CASE
+  WHEN LOWER(SUBSTR(sql, -8)) = ', strict' THEN SUBSTR(sql, 1, LENGTH(sql) - 8)
+  WHEN LOWER(SUBSTR(sql, -7)) = ' strict' THEN SUBSTR(sql, 1, LENGTH(sql) - 7)
+  ELSE sql
+END
+WHERE type = 'table' AND name != 'sqlite_sequence';
+
+UPDATE sqlite_master
+SET sql = replace(sql, 'device_token BLOB NOT NULL', 'device_token TEXT NOT NULL')
+WHERE type = 'table' AND name = 'ntf_tokens';
+
+PRAGMA writable_schema=RESET;
+
+UPDATE ntf_tokens SET ntf_mode = CAST(ntf_mode as BLOB);
+
+UPDATE ntf_subscriptions
+SET ntf_sub_action = CAST(ntf_sub_action as BLOB),
+    ntf_sub_smp_action = CAST(ntf_sub_smp_action as BLOB);
+|]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/agent_schema.sql

@@ -1,15 +1,14 @@
 CREATE TABLE migrations(
-  name TEXT NOT NULL,
+  name TEXT NOT NULL PRIMARY KEY,
   ts TEXT NOT NULL,
-  down TEXT,
-  PRIMARY KEY(name)
-);
+  down TEXT
+) STRICT;
 CREATE TABLE servers(
   host TEXT NOT NULL,
   port TEXT NOT NULL,
   key_hash BLOB NOT NULL,
   PRIMARY KEY(host, port)
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE connections(
   conn_id BLOB NOT NULL PRIMARY KEY,
   conn_mode TEXT NOT NULL,
@@ -29,7 +28,7 @@ CREATE TABLE connections(
   ratchet_sync_state TEXT NOT NULL DEFAULT 'ok',
   deleted_at_wait_delivery TEXT,
   pq_support INTEGER NOT NULL DEFAULT 0
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE rcv_queues(
   host TEXT NOT NULL,
   port TEXT NOT NULL,
@@ -61,11 +60,14 @@ CREATE TABLE rcv_queues(
   link_priv_sig_key BLOB,
   link_enc_fixed_data BLOB,
   queue_mode TEXT,
+  to_subscribe INTEGER NOT NULL DEFAULT 0,
+  client_notice_id INTEGER
+  REFERENCES client_notices ON UPDATE RESTRICT ON DELETE SET NULL,
   PRIMARY KEY(host, port, rcv_id),
   FOREIGN KEY(host, port) REFERENCES servers
   ON DELETE RESTRICT ON UPDATE CASCADE,
   UNIQUE(host, port, snd_id)
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE snd_queues(
   host TEXT NOT NULL,
   port TEXT NOT NULL,
@@ -87,7 +89,7 @@ CREATE TABLE snd_queues(
   PRIMARY KEY(host, port, snd_id),
   FOREIGN KEY(host, port) REFERENCES servers
   ON DELETE RESTRICT ON UPDATE CASCADE
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE messages(
   conn_id BLOB NOT NULL REFERENCES connections(conn_id)
   ON DELETE CASCADE,
@@ -104,7 +106,7 @@ CREATE TABLE messages(
   ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED,
   FOREIGN KEY(conn_id, internal_snd_id) REFERENCES snd_messages
   ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE rcv_messages(
   conn_id BLOB NOT NULL,
   internal_rcv_id INTEGER NOT NULL,
@@ -120,7 +122,7 @@ CREATE TABLE rcv_messages(
   PRIMARY KEY(conn_id, internal_rcv_id),
   FOREIGN KEY(conn_id, internal_id) REFERENCES messages
   ON DELETE CASCADE
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE snd_messages(
   conn_id BLOB NOT NULL,
   internal_snd_id INTEGER NOT NULL,
@@ -137,7 +139,7 @@ CREATE TABLE snd_messages(
   PRIMARY KEY(conn_id, internal_snd_id),
   FOREIGN KEY(conn_id, internal_id) REFERENCES messages
   ON DELETE CASCADE
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE conn_confirmations(
   confirmation_id BLOB NOT NULL PRIMARY KEY,
   conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
@@ -151,7 +153,7 @@ CREATE TABLE conn_confirmations(
   ,
   smp_reply_queues BLOB NULL,
   smp_client_version INTEGER
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE conn_invitations(
   invitation_id BLOB NOT NULL PRIMARY KEY,
   contact_conn_id BLOB REFERENCES connections ON DELETE SET NULL,
@@ -160,7 +162,7 @@ CREATE TABLE conn_invitations(
   accepted INTEGER NOT NULL DEFAULT 0,
   own_conn_info BLOB,
   created_at TEXT NOT NULL DEFAULT(datetime('now'))
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE ratchets(
   conn_id BLOB NOT NULL PRIMARY KEY REFERENCES connections
   ON DELETE CASCADE,
@@ -175,7 +177,7 @@ CREATE TABLE ratchets(
   x3dh_pub_key_2 BLOB,
   pq_priv_kem BLOB,
   pq_pub_kem BLOB
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE skipped_messages(
   skipped_message_id INTEGER PRIMARY KEY,
   conn_id BLOB NOT NULL REFERENCES ratchets
@@ -183,7 +185,7 @@ CREATE TABLE skipped_messages(
   header_key BLOB NOT NULL,
   msg_n INTEGER NOT NULL,
   msg_key BLOB NOT NULL
-);
+) STRICT;
 CREATE TABLE ntf_servers(
   ntf_host TEXT NOT NULL,
   ntf_port TEXT NOT NULL,
@@ -191,10 +193,10 @@ CREATE TABLE ntf_servers(
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now')),
   PRIMARY KEY(ntf_host, ntf_port)
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE ntf_tokens(
   provider TEXT NOT NULL, -- apns
-  device_token TEXT NOT NULL, -- ! this field is mislabeled and is actually saved as binary
+  device_token BLOB NOT NULL,
   ntf_host TEXT NOT NULL,
   ntf_port TEXT NOT NULL,
   tkn_id BLOB, -- token ID assigned by notifications server
@@ -211,7 +213,7 @@ tkn_dh_secret BLOB, -- DH secret for e2e encryption of notifications
   PRIMARY KEY(provider, device_token, ntf_host, ntf_port),
   FOREIGN KEY(ntf_host, ntf_port) REFERENCES ntf_servers
   ON DELETE RESTRICT ON UPDATE CASCADE
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE ntf_subscriptions(
   conn_id BLOB NOT NULL,
   smp_host TEXT NULL,
@@ -235,7 +237,7 @@ CREATE TABLE ntf_subscriptions(
   ON DELETE SET NULL ON UPDATE CASCADE,
   FOREIGN KEY(ntf_host, ntf_port) REFERENCES ntf_servers
   ON DELETE RESTRICT ON UPDATE CASCADE
-) WITHOUT ROWID;
+) WITHOUT ROWID, STRICT;
 CREATE TABLE commands(
   command_id INTEGER PRIMARY KEY,
   conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
@@ -250,7 +252,7 @@ CREATE TABLE commands(
   failed INTEGER DEFAULT 0,
   FOREIGN KEY(host, port) REFERENCES servers
   ON DELETE RESTRICT ON UPDATE CASCADE
-);
+) STRICT;
 CREATE TABLE snd_message_deliveries(
   snd_message_delivery_id INTEGER PRIMARY KEY AUTOINCREMENT,
   conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
@@ -258,13 +260,13 @@ CREATE TABLE snd_message_deliveries(
   internal_id INTEGER NOT NULL,
   failed INTEGER DEFAULT 0,
   FOREIGN KEY(conn_id, internal_id) REFERENCES messages ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED
-);
+) STRICT;
 CREATE TABLE sqlite_sequence(name,seq);
 CREATE TABLE users(
   user_id INTEGER PRIMARY KEY AUTOINCREMENT
   ,
   deleted INTEGER DEFAULT 0 CHECK(deleted NOT NULL)
-);
+) STRICT;
 CREATE TABLE xftp_servers(
   xftp_server_id INTEGER PRIMARY KEY,
   xftp_host TEXT NOT NULL,
@@ -273,7 +275,7 @@ CREATE TABLE xftp_servers(
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now')),
   UNIQUE(xftp_host, xftp_port, xftp_key_hash)
-);
+) STRICT;
 CREATE TABLE rcv_files(
   rcv_file_id INTEGER PRIMARY KEY,
   rcv_file_entity_id BLOB NOT NULL,
@@ -300,7 +302,7 @@ CREATE TABLE rcv_files(
   redirect_digest BLOB,
   approved_relays INTEGER NOT NULL DEFAULT 0,
   UNIQUE(rcv_file_entity_id)
-);
+) STRICT;
 CREATE TABLE rcv_file_chunks(
   rcv_file_chunk_id INTEGER PRIMARY KEY,
   rcv_file_id INTEGER NOT NULL REFERENCES rcv_files ON DELETE CASCADE,
@@ -310,7 +312,7 @@ CREATE TABLE rcv_file_chunks(
   tmp_path TEXT,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE rcv_file_chunk_replicas(
   rcv_file_chunk_replica_id INTEGER PRIMARY KEY,
   rcv_file_chunk_id INTEGER NOT NULL REFERENCES rcv_file_chunks ON DELETE CASCADE,
@@ -323,7 +325,7 @@ CREATE TABLE rcv_file_chunk_replicas(
   retries INTEGER NOT NULL DEFAULT 0,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE snd_files(
   snd_file_id INTEGER PRIMARY KEY,
   snd_file_entity_id BLOB NOT NULL,
@@ -345,7 +347,7 @@ CREATE TABLE snd_files(
   failed INTEGER DEFAULT 0,
   redirect_size INTEGER,
   redirect_digest BLOB
-);
+) STRICT;
 CREATE TABLE snd_file_chunks(
   snd_file_chunk_id INTEGER PRIMARY KEY,
   snd_file_id INTEGER NOT NULL REFERENCES snd_files ON DELETE CASCADE,
@@ -355,7 +357,7 @@ CREATE TABLE snd_file_chunks(
   digest BLOB NOT NULL,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE snd_file_chunk_replicas(
   snd_file_chunk_replica_id INTEGER PRIMARY KEY,
   snd_file_chunk_id INTEGER NOT NULL REFERENCES snd_file_chunks ON DELETE CASCADE,
@@ -368,7 +370,7 @@ CREATE TABLE snd_file_chunk_replicas(
   retries INTEGER NOT NULL DEFAULT 0,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE snd_file_chunk_replica_recipients(
   snd_file_chunk_replica_recipient_id INTEGER PRIMARY KEY,
   snd_file_chunk_replica_id INTEGER NOT NULL REFERENCES snd_file_chunk_replicas ON DELETE CASCADE,
@@ -376,7 +378,7 @@ CREATE TABLE snd_file_chunk_replica_recipients(
   rcv_replica_key BLOB NOT NULL,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE deleted_snd_chunk_replicas(
   deleted_snd_chunk_replica_id INTEGER PRIMARY KEY,
   user_id INTEGER NOT NULL REFERENCES users ON DELETE CASCADE,
@@ -390,28 +392,28 @@ CREATE TABLE deleted_snd_chunk_replicas(
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
   ,
   failed INTEGER DEFAULT 0
-);
+) STRICT;
 CREATE TABLE encrypted_rcv_message_hashes(
   encrypted_rcv_message_hash_id INTEGER PRIMARY KEY,
   conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
   hash BLOB NOT NULL,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE processed_ratchet_key_hashes(
   processed_ratchet_key_hash_id INTEGER PRIMARY KEY,
   conn_id BLOB NOT NULL REFERENCES connections ON DELETE CASCADE,
   hash BLOB NOT NULL,
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE servers_stats(
   servers_stats_id INTEGER PRIMARY KEY,
   servers_stats TEXT,
   started_at TEXT NOT NULL DEFAULT(datetime('now')),
   created_at TEXT NOT NULL DEFAULT(datetime('now')),
   updated_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE ntf_tokens_to_delete(
   ntf_token_to_delete_id INTEGER PRIMARY KEY,
   ntf_host TEXT NOT NULL,
@@ -421,11 +423,11 @@ CREATE TABLE ntf_tokens_to_delete(
   tkn_priv_key BLOB NOT NULL, -- client's private key to sign token commands,
 del_failed INTEGER DEFAULT 0,
 created_at TEXT NOT NULL DEFAULT(datetime('now'))
-);
+) STRICT;
 CREATE TABLE snd_message_bodies(
   snd_message_body_id INTEGER PRIMARY KEY,
   agent_msg BLOB NOT NULL DEFAULT x''
-);
+) STRICT;
 CREATE TABLE inv_short_links(
   inv_short_link_id INTEGER PRIMARY KEY AUTOINCREMENT,
   host TEXT NOT NULL,
@@ -436,7 +438,18 @@ CREATE TABLE inv_short_links(
   snd_private_key BLOB NOT NULL,
   snd_id BLOB,
   FOREIGN KEY(host, port) REFERENCES servers ON DELETE RESTRICT ON UPDATE CASCADE
-);
+) STRICT;
+CREATE TABLE client_notices(
+  client_notice_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  protocol TEXT NOT NULL,
+  host TEXT NOT NULL,
+  port TEXT NOT NULL,
+  entity_id BLOB NOT NULL,
+  server_key_hash BLOB,
+  notice_ttl INTEGER,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL
+) 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);
@@ -572,3 +585,11 @@ CREATE UNIQUE INDEX idx_inv_short_links_link_id ON inv_short_links(
   port,
   link_id
 );
+CREATE INDEX idx_rcv_queues_to_subscribe ON rcv_queues(to_subscribe);
+CREATE UNIQUE INDEX idx_client_notices_entity ON client_notices(
+  protocol,
+  host,
+  port,
+  entity_id
+);
+CREATE INDEX idx_rcv_queues_client_notice_id ON rcv_queues(client_notice_id);

src/Simplex/Messaging/Agent/Store/SQLite/Util.hs

@@ -0,0 +1,94 @@
+module Simplex.Messaging.Agent.Store.SQLite.Util
+  ( SQLiteFunc,
+    SQLiteFuncFinal,
+    createStaticFunction,
+    createStaticAggregate,
+  ) where
+
+import Control.Exception (SomeException, catch, mask_)
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as B
+import Data.IORef
+import Database.SQLite3.Direct (Database (..), FuncArgs (..), FuncContext (..))
+import Database.SQLite3.Bindings
+import Foreign.C.String
+import Foreign.Ptr
+import Foreign.StablePtr
+import Foreign.Storable
+
+data CFuncPtrs = CFuncPtrs (FunPtr CFunc) (FunPtr CFunc) (FunPtr CFuncFinal)
+
+type SQLiteFunc = Ptr CContext -> CArgCount -> Ptr (Ptr CValue) -> IO ()
+
+type SQLiteFuncFinal = Ptr CContext -> IO ()
+
+mkSQLiteFunc :: (FuncContext -> FuncArgs -> IO ()) -> SQLiteFunc
+mkSQLiteFunc f cxt nArgs cvals = catchAsResultError cxt $ f (FuncContext cxt) (FuncArgs nArgs cvals)
+{-# INLINE mkSQLiteFunc #-}
+
+-- Based on createFunction from Database.SQLite3.Direct, but uses static function pointer to avoid dynamic wrapper that triggers DCL.
+createStaticFunction :: Database -> ByteString -> CArgCount -> Bool -> FunPtr SQLiteFunc -> IO (Either Error ())
+createStaticFunction (Database db) name nArgs isDet funPtr = mask_ $ do
+  u <- newStablePtr $ CFuncPtrs funPtr nullFunPtr nullFunPtr
+  let flags = if isDet then c_SQLITE_DETERMINISTIC else 0
+  B.useAsCString name $ \namePtr ->
+    toResult () <$> c_sqlite3_create_function_v2 db namePtr nArgs flags (castStablePtrToPtr u) funPtr nullFunPtr nullFunPtr nullFunPtr
+
+mkSQLiteAggStep :: a -> (FuncContext -> FuncArgs -> a -> IO a) -> SQLiteFunc
+mkSQLiteAggStep initSt xStep cxt nArgs cvals = catchAsResultError cxt $ do
+  -- we store the aggregate state in the buffer returned by
+  -- c_sqlite3_aggregate_context as a StablePtr pointing to an IORef that
+  -- contains the actual aggregate state
+  aggCtx <- getAggregateContext cxt
+  aggStPtr <- peek aggCtx
+  aggStRef <-
+    if castStablePtrToPtr aggStPtr /= nullPtr
+      then deRefStablePtr aggStPtr
+      else do
+        aggStRef <- newIORef initSt
+        aggStPtr' <- newStablePtr aggStRef
+        poke aggCtx aggStPtr'
+        return aggStRef
+  aggSt <- readIORef aggStRef
+  aggSt' <- xStep (FuncContext cxt) (FuncArgs nArgs cvals) aggSt
+  writeIORef aggStRef aggSt'
+
+mkSQLiteAggFinal :: a -> (FuncContext -> a -> IO ()) -> SQLiteFuncFinal
+mkSQLiteAggFinal initSt xFinal cxt = do
+  aggCtx <- getAggregateContext cxt
+  aggStPtr <- peek aggCtx
+  if castStablePtrToPtr aggStPtr == nullPtr
+    then catchAsResultError cxt $ xFinal (FuncContext cxt) initSt
+    else do
+      catchAsResultError cxt $ do
+        aggStRef <- deRefStablePtr aggStPtr
+        aggSt <- readIORef aggStRef
+        xFinal (FuncContext cxt) aggSt
+      freeStablePtr aggStPtr
+
+getAggregateContext :: Ptr CContext -> IO (Ptr a)
+getAggregateContext cxt = c_sqlite3_aggregate_context cxt stPtrSize
+  where
+    stPtrSize = fromIntegral $ sizeOf (undefined :: StablePtr ())
+
+-- Based on createAggregate from Database.SQLite3.Direct, but uses static function pointers to avoid dynamic wrappers that trigger DCL.
+createStaticAggregate :: Database -> ByteString -> CArgCount -> FunPtr SQLiteFunc -> FunPtr SQLiteFuncFinal -> IO (Either Error ())
+createStaticAggregate (Database db) name nArgs stepPtr finalPtr = mask_ $ do
+  u <- newStablePtr $ CFuncPtrs nullFunPtr stepPtr finalPtr
+  B.useAsCString name $ \namePtr ->
+    toResult () <$> c_sqlite3_create_function_v2 db namePtr nArgs 0 (castStablePtrToPtr u) nullFunPtr stepPtr finalPtr nullFunPtr
+
+-- Convert a 'CError' to a 'Either Error', in the common case where
+-- SQLITE_OK signals success and anything else signals an error.
+--
+-- Note that SQLITE_OK == 0.
+toResult :: a -> CError -> Either Error a
+toResult a (CError 0) = Right a
+toResult _ code = Left $ decodeError code
+
+-- call c_sqlite3_result_error in the event of an error
+catchAsResultError :: Ptr CContext -> IO () -> IO ()
+catchAsResultError ctx action = catch action $ \exn -> do
+  let msg = show (exn :: SomeException)
+  withCAStringLen msg $ \(ptr, len) ->
+    c_sqlite3_result_error ctx ptr (fromIntegral len)

src/Simplex/Messaging/Agent/Store/Shared.hs

@@ -9,6 +9,7 @@ module Simplex.Messaging.Agent.Store.Shared
     DownMigration (..),
     MTRError (..),
     mtrErrorDescription,
+    MigrationConfig (..),
     MigrationConfirmation (..),
     MigrationError (..),
     UpMigration (..),
@@ -55,13 +56,15 @@ data MigrationError
   | MigrationError {mtrError :: MTRError}
   deriving (Eq, Show)
 
-migrationErrorDescription :: MigrationError -> String
-migrationErrorDescription = \case
+migrationErrorDescription :: Bool -> MigrationError -> String
+migrationErrorDescription withBackup = \case
   MEUpgrade ums ->
-    "The app has a newer version than the database.\nConfirm to back up and upgrade using these migrations: " <> intercalate ", " (map upName ums)
+    "The app has a newer version than the database.\nConfirm to " <> backupStr <> "upgrade using these migrations: " <> intercalate ", " (map upName ums)
   MEDowngrade dms ->
-    "Database version is newer than the app.\nConfirm to back up and downgrade using these migrations: " <> intercalate ", " dms
+    "Database version is newer than the app.\nConfirm to " <> backupStr <> "downgrade using these migrations: " <> intercalate ", " dms
   MigrationError err -> mtrErrorDescription err
+  where
+    backupStr = if withBackup then "back up and " else ""
 
 data UpMigration = UpMigration {upName :: String, withDown :: Bool}
   deriving (Eq, Show)
@@ -69,6 +72,11 @@ data UpMigration = UpMigration {upName :: String, withDown :: Bool}
 upMigration :: Migration -> UpMigration
 upMigration Migration {name, down} = UpMigration name $ isJust down
 
+data MigrationConfig = MigrationConfig
+  { confirm :: MigrationConfirmation,
+    backupPath :: Maybe FilePath -- Nothing - no backup, empty string - the same folder
+  }
+
 data MigrationConfirmation = MCYesUp | MCYesUpDown | MCConsole | MCError
   deriving (Eq, Show)
 

src/Simplex/Messaging/Agent/TRcvQueues.hs

@@ -1,120 +0,0 @@
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE LambdaCase #-}
-
-module Simplex.Messaging.Agent.TRcvQueues
-  ( TRcvQueues (getRcvQueues, getConnections),
-    Queue (..),
-    empty,
-    clear,
-    deleteConn,
-    hasConn,
-    addQueue,
-    batchAddQueues,
-    deleteQueue,
-    hasSessQueues,
-    getSessQueues,
-    getDelSessQueues,
-  )
-where
-
-import Control.Concurrent.STM
-import Data.Foldable (foldl')
-import Data.List.NonEmpty (NonEmpty (..), (<|))
-import qualified Data.List.NonEmpty as L
-import qualified Data.Map.Strict as M
-import Simplex.Messaging.Agent.Protocol (ConnId, UserId)
-import Simplex.Messaging.Agent.Store (RcvQueue, StoredRcvQueue (..))
-import Simplex.Messaging.Protocol (RecipientId, SMPServer)
-import Simplex.Messaging.TMap (TMap)
-import qualified Simplex.Messaging.TMap as TM
-import Simplex.Messaging.Transport
-
-class Queue q where
-  connId' :: q -> ConnId
-  qKey :: q -> (UserId, SMPServer, RecipientId)
-
--- the fields in this record have the same data with swapped keys for lookup efficiency,
--- and all methods must maintain this invariant.
-data TRcvQueues q = TRcvQueues
-  { getRcvQueues :: TMap (UserId, SMPServer, RecipientId) q,
-    getConnections :: TMap ConnId (NonEmpty (UserId, SMPServer, RecipientId))
-  }
-
-empty :: IO (TRcvQueues q)
-empty = TRcvQueues <$> TM.emptyIO <*> TM.emptyIO
-
-clear :: TRcvQueues q -> STM ()
-clear (TRcvQueues qs cs) = TM.clear qs >> TM.clear cs
-
-deleteConn :: ConnId -> TRcvQueues q -> STM ()
-deleteConn cId (TRcvQueues qs cs) =
-  TM.lookupDelete cId cs >>= \case
-    Just ks -> modifyTVar' qs $ \qs' -> foldl' (flip M.delete) qs' ks
-    Nothing -> pure ()
-
-hasConn :: ConnId -> TRcvQueues q -> STM Bool
-hasConn cId (TRcvQueues _ cs) = TM.member cId cs
-
-addQueue :: Queue q => q -> TRcvQueues q -> STM ()
-addQueue rq (TRcvQueues qs cs) = do
-  TM.insert k rq qs
-  TM.alter addQ (connId' rq) cs
-  where
-    addQ = Just . maybe (k :| []) (k <|)
-    k = qKey rq
-
--- Save time by aggregating modifyTVar'
-batchAddQueues :: (Foldable t, Queue q) => TRcvQueues q -> t q -> STM ()
-batchAddQueues (TRcvQueues qs cs) rqs = do
-  modifyTVar' qs $ \now -> foldl' (\rqs' rq -> M.insert (qKey rq) rq rqs') now rqs
-  modifyTVar' cs $ \now -> foldl' (\cs' rq -> M.alter (addQ $ qKey rq) (connId' rq) cs') now rqs
-  where
-    addQ k = Just . maybe (k :| []) (k <|)
-
-deleteQueue :: RcvQueue -> TRcvQueues RcvQueue -> STM ()
-deleteQueue rq (TRcvQueues qs cs) = do
-  TM.delete k qs
-  TM.update delQ (connId rq) cs
-  where
-    delQ = L.nonEmpty . L.filter (/= k)
-    k = qKey rq
-
-hasSessQueues :: (UserId, SMPServer, Maybe ConnId) -> TRcvQueues RcvQueue -> STM Bool
-hasSessQueues tSess (TRcvQueues qs _) = any (`isSession` tSess) <$> readTVar qs
-
-getSessQueues :: (UserId, SMPServer, Maybe ConnId) -> TRcvQueues RcvQueue -> IO [RcvQueue]
-getSessQueues tSess (TRcvQueues qs _) = M.foldl' addQ [] <$> readTVarIO qs
-  where
-    addQ qs' rq = if rq `isSession` tSess then rq : qs' else qs'
-
-getDelSessQueues :: (UserId, SMPServer, Maybe ConnId) -> SessionId -> TRcvQueues (SessionId, RcvQueue) -> STM ([RcvQueue], [ConnId])
-getDelSessQueues tSess sessId' (TRcvQueues qs cs) = do
-  (removedQs, qs'') <- (\qs' -> M.foldl' delQ ([], qs') qs') <$> readTVar qs
-  writeTVar qs $! qs''
-  removedConns <- stateTVar cs $ \cs' -> foldl' delConn ([], cs') removedQs
-  pure (removedQs, removedConns)
-  where
-    delQ acc@(removed, qs') (sessId, rq)
-      | rq `isSession` tSess && sessId == sessId' = (rq : removed, M.delete (qKey rq) qs')
-      | otherwise = acc
-    delConn :: ([ConnId], M.Map ConnId (NonEmpty (UserId, SMPServer, RecipientId))) -> RcvQueue -> ([ConnId], M.Map ConnId (NonEmpty (UserId, SMPServer, RecipientId)))
-    delConn (removed, cs') rq = M.alterF f cId cs'
-      where
-        cId = connId rq
-        f = \case
-          Just ks -> case L.nonEmpty $ L.filter (qKey rq /=) ks of
-            Just ks' -> (removed, Just ks')
-            Nothing -> (cId : removed, Nothing)
-          Nothing -> (removed, Nothing) -- "impossible" in invariant holds, because we get keys from the known queues
-
-isSession :: RcvQueue -> (UserId, SMPServer, Maybe ConnId) -> Bool
-isSession rq (uId, srv, connId_) =
-  userId rq == uId && server rq == srv && maybe True (connId rq ==) connId_
-
-instance Queue RcvQueue where
-  connId' = connId
-  qKey rq = (userId rq, server rq, rcvId rq)
-
-instance Queue (SessionId, RcvQueue) where
-  connId' = connId . snd
-  qKey = qKey . snd

src/Simplex/Messaging/Agent/TSessionSubs.hs

@@ -0,0 +1,201 @@
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Simplex.Messaging.Agent.TSessionSubs
+  ( TSessionSubs (sessionSubs),
+    SessSubs (..),
+    emptyIO,
+    clear,
+    hasActiveSub,
+    hasPendingSub,
+    addPendingSub,
+    setSessionId,
+    addActiveSub,
+    batchAddActiveSubs,
+    batchAddPendingSubs,
+    deletePendingSub,
+    batchDeletePendingSubs,
+    deleteSub,
+    batchDeleteSubs,
+    hasPendingSubs,
+    getPendingSubs,
+    getActiveSubs,
+    setSubsPending,
+    updateClientNotices,
+    foldSessionSubs,
+    mapSubs,
+  )
+where
+
+import Control.Concurrent.STM
+import Control.Monad
+import Data.Int (Int64)
+import Data.List (foldl')
+import Data.Map.Strict (Map)
+import qualified Data.Map.Strict as M
+import Data.Maybe (isJust)
+import qualified Data.Set as S
+import Simplex.Messaging.Agent.Protocol (SMPQueue (..))
+import Simplex.Messaging.Agent.Store (RcvQueueSub (..), SomeRcvQueue)
+import Simplex.Messaging.Client (SMPTransportSession, TransportSessionMode (..))
+import Simplex.Messaging.Protocol (RecipientId)
+import Simplex.Messaging.TMap (TMap)
+import qualified Simplex.Messaging.TMap as TM
+import Simplex.Messaging.Transport
+import Simplex.Messaging.Util (($>>=))
+
+data TSessionSubs = TSessionSubs
+  { sessionSubs :: TMap SMPTransportSession SessSubs
+  }
+
+data SessSubs = SessSubs
+  { subsSessId :: TVar (Maybe SessionId),
+    activeSubs :: TMap RecipientId RcvQueueSub,
+    pendingSubs :: TMap RecipientId RcvQueueSub
+  }
+
+emptyIO :: IO TSessionSubs
+emptyIO = TSessionSubs <$> TM.emptyIO
+{-# INLINE emptyIO #-}
+
+clear :: TSessionSubs -> STM ()
+clear = TM.clear . sessionSubs
+{-# INLINE clear #-}
+
+lookupSubs :: SMPTransportSession -> TSessionSubs -> STM (Maybe SessSubs)
+lookupSubs tSess = TM.lookup tSess . sessionSubs
+{-# INLINE lookupSubs #-}
+
+getSessSubs :: SMPTransportSession -> TSessionSubs -> STM SessSubs
+getSessSubs tSess ss = lookupSubs tSess ss >>= maybe new pure
+  where
+    new = do
+      s <- SessSubs <$> newTVar Nothing <*> newTVar M.empty <*> newTVar M.empty
+      TM.insert tSess s $ sessionSubs ss
+      pure s
+
+hasActiveSub :: SMPTransportSession -> RecipientId -> TSessionSubs -> STM Bool
+hasActiveSub = hasQueue_ activeSubs
+{-# INLINE hasActiveSub #-}
+
+hasPendingSub :: SMPTransportSession -> RecipientId -> TSessionSubs -> STM Bool
+hasPendingSub = hasQueue_ pendingSubs
+{-# INLINE hasPendingSub #-}
+
+hasQueue_ :: (SessSubs -> TMap RecipientId RcvQueueSub) -> SMPTransportSession -> RecipientId -> TSessionSubs -> STM Bool
+hasQueue_ subs tSess rId ss = isJust <$> (lookupSubs tSess ss $>>= TM.lookup rId . subs)
+{-# INLINE hasQueue_ #-}
+
+addPendingSub :: SMPTransportSession -> RcvQueueSub -> TSessionSubs -> STM ()
+addPendingSub tSess rq ss = getSessSubs tSess ss >>= TM.insert (rcvId rq) rq . pendingSubs
+
+setSessionId :: SMPTransportSession -> SessionId -> TSessionSubs -> STM ()
+setSessionId tSess sessId ss = do
+  s <- getSessSubs tSess ss
+  readTVar (subsSessId s) >>= \case
+    Nothing -> writeTVar (subsSessId s) (Just sessId)
+    Just sessId' -> unless (sessId == sessId') $ void $ setSubsPending_ s $ Just sessId
+
+addActiveSub :: SMPTransportSession -> SessionId -> RcvQueueSub -> TSessionSubs -> STM ()
+addActiveSub tSess sessId rq ss = do
+  s <- getSessSubs tSess ss
+  sessId' <- readTVar $ subsSessId s
+  let rId = rcvId rq
+  if Just sessId == sessId'
+    then do
+      TM.insert rId rq $ activeSubs s
+      TM.delete rId $ pendingSubs s
+    else TM.insert rId rq $ pendingSubs s
+
+batchAddActiveSubs :: SMPTransportSession -> SessionId -> [RcvQueueSub] -> TSessionSubs -> STM ()
+batchAddActiveSubs tSess sessId rqs ss = do
+  s <- getSessSubs tSess ss
+  sessId' <- readTVar $ subsSessId s
+  let qs = M.fromList $ map (\rq -> (rcvId rq, rq)) rqs
+  if Just sessId == sessId'
+    then do
+      TM.union qs $ activeSubs s
+      modifyTVar' (pendingSubs s) (`M.difference` qs)
+    else TM.union qs $ pendingSubs s
+
+batchAddPendingSubs :: SMPTransportSession -> [RcvQueueSub] -> TSessionSubs -> STM ()
+batchAddPendingSubs tSess rqs ss = do
+  s <- getSessSubs tSess ss
+  modifyTVar' (pendingSubs s) $ M.union $ M.fromList $ map (\rq -> (rcvId rq, rq)) rqs
+
+deletePendingSub :: SMPTransportSession -> RecipientId -> TSessionSubs -> STM ()
+deletePendingSub tSess rId = lookupSubs tSess >=> mapM_ (TM.delete rId . pendingSubs)
+
+batchDeletePendingSubs :: SMPTransportSession -> S.Set RecipientId -> TSessionSubs -> STM ()
+batchDeletePendingSubs tSess rIds = lookupSubs tSess >=> mapM_ (delete . pendingSubs)
+  where
+    delete = (`modifyTVar'` (`M.withoutKeys` rIds))
+
+deleteSub :: SMPTransportSession -> RecipientId -> TSessionSubs -> STM ()
+deleteSub tSess rId = lookupSubs tSess >=> mapM_ (\s -> TM.delete rId (activeSubs s) >> TM.delete rId (pendingSubs s))
+
+batchDeleteSubs :: SomeRcvQueue q => SMPTransportSession -> [q] -> TSessionSubs -> STM ()
+batchDeleteSubs tSess rqs = lookupSubs tSess >=> mapM_ (\s -> delete (activeSubs s) >> delete (pendingSubs s))
+  where
+    rIds = S.fromList $ map queueId rqs
+    delete = (`modifyTVar'` (`M.withoutKeys` rIds))
+
+hasPendingSubs :: SMPTransportSession -> TSessionSubs -> STM Bool
+hasPendingSubs tSess = lookupSubs tSess >=> maybe (pure False) (fmap (not . null) . readTVar . pendingSubs)
+
+getPendingSubs :: SMPTransportSession -> TSessionSubs -> STM (Map RecipientId RcvQueueSub)
+getPendingSubs = getSubs_ pendingSubs
+{-# INLINE getPendingSubs #-}
+
+getActiveSubs :: SMPTransportSession -> TSessionSubs -> STM (Map RecipientId RcvQueueSub)
+getActiveSubs = getSubs_ activeSubs
+{-# INLINE getActiveSubs #-}
+
+getSubs_ :: (SessSubs -> TMap RecipientId RcvQueueSub) -> SMPTransportSession -> TSessionSubs -> STM (Map RecipientId RcvQueueSub)
+getSubs_ subs tSess = lookupSubs tSess >=> maybe (pure M.empty) (readTVar . subs)
+
+setSubsPending :: TransportSessionMode -> SMPTransportSession -> SessionId -> TSessionSubs -> STM (Map RecipientId RcvQueueSub)
+setSubsPending mode tSess@(uId, srv, connId_) sessId tss@(TSessionSubs ss)
+  | entitySession == isJust connId_ =
+      TM.lookup tSess ss >>= withSessSubs (`setSubsPending_` Nothing)
+  | otherwise =
+      TM.lookupDelete tSess ss >>= withSessSubs setPendingChangeMode
+  where
+    entitySession = mode == TSMEntity
+    sessEntId = if entitySession then Just else const Nothing
+    withSessSubs run = \case
+      Nothing -> pure M.empty
+      Just s -> do
+        sessId' <- readTVar $ subsSessId s
+        if Just sessId == sessId' then run s else pure M.empty
+    setPendingChangeMode s = do
+      subs <- M.union <$> readTVar (activeSubs s) <*> readTVar (pendingSubs s)
+      unless (null subs) $
+        forM_ subs $ \rq -> addPendingSub (uId, srv, sessEntId (connId rq)) rq tss
+      pure subs
+
+setSubsPending_ :: SessSubs -> Maybe SessionId -> STM (Map RecipientId RcvQueueSub)
+setSubsPending_ s sessId_ = do
+  writeTVar (subsSessId s) sessId_
+  let as = activeSubs s
+  subs <- readTVar as
+  unless (null subs) $ do
+    writeTVar as M.empty
+    modifyTVar' (pendingSubs s) $ M.union subs
+  pure subs
+
+updateClientNotices :: SMPTransportSession -> [(RecipientId, Maybe Int64)] -> TSessionSubs -> STM ()
+updateClientNotices tSess noticeIds ss = do
+  s <- getSessSubs tSess ss
+  modifyTVar' (pendingSubs s) $ \m -> foldl' (\m' (rcvId, clientNoticeId) -> M.adjust (\rq -> rq {clientNoticeId}) rcvId m') m noticeIds
+
+foldSessionSubs :: (a -> (SMPTransportSession, SessSubs) -> IO a) -> a -> TSessionSubs -> IO a
+foldSessionSubs f a = foldM f a . M.assocs <=< readTVarIO . sessionSubs
+
+mapSubs :: (Map RecipientId RcvQueueSub -> a) -> SessSubs -> IO (a, a)
+mapSubs f s = do
+  active <- readTVarIO $ activeSubs s
+  pending <- readTVarIO $ pendingSubs s
+  pure (f active, f pending)

src/Simplex/Messaging/Client.hs

@@ -29,6 +29,7 @@
 module Simplex.Messaging.Client
   ( -- * Connect (disconnect) client to (from) SMP server
     TransportSession,
+    SMPTransportSession,
     ProtocolClient (thParams, sessionTs),
     SMPClient,
     ProxiedRelay (..),
@@ -38,6 +39,8 @@ module Simplex.Messaging.Client
     protocolClientServer',
     transportHost',
     transportSession',
+    useWebPort,
+    isPresetDomain,
 
     -- * SMP protocol command functions
     createSMPQueue,
@@ -101,6 +104,7 @@ module Simplex.Messaging.Client
     temporaryClientError,
     smpClientServiceError,
     smpProxyError,
+    smpErrorClientNotice,
     textToHostMode,
     ServerTransmissionBatch,
     ServerTransmission (..),
@@ -155,11 +159,13 @@ import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
 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.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport
 import Simplex.Messaging.Transport.Client (SocksAuth (..), SocksProxyWithAuth (..), TransportClientConfig (..), TransportHost (..), defaultSMPPort, runTransportClient)
+import Simplex.Messaging.Transport.HTTP2 (httpALPN11)
 import Simplex.Messaging.Transport.KeepAlive
 import Simplex.Messaging.Util
 import Simplex.Messaging.Version
@@ -547,6 +553,8 @@ type UserId = Int64
 -- Please note that for SMP connection ID is used as entity ID, not queue ID.
 type TransportSession msg = (UserId, ProtoServer msg, Maybe ByteString)
 
+type SMPTransportSession = TransportSession BrokerMsg
+
 -- | Connects to 'ProtocolServer' using passed client configuration
 -- and queue for messages and notifications.
 --
@@ -560,7 +568,7 @@ getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qS
         `catch` \(e :: IOException) -> pure . Left $ PCEIOError e
     Left e -> pure $ Left e
   where
-    NetworkConfig {smpWebPortServers, tcpConnectTimeout, tcpTimeout, smpPingInterval} = networkConfig
+    NetworkConfig {tcpConnectTimeout, tcpTimeout, smpPingInterval} = networkConfig
     mkProtocolClient :: TransportHost -> UTCTime -> IO (PClient v err msg)
     mkProtocolClient transportHost ts = do
       connected <- newTVarIO False
@@ -591,30 +599,30 @@ getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qS
     runClient :: (ServiceName, ATransport 'TClient) -> TransportHost -> PClient v err msg -> IO (Either (ProtocolClientError err) (ProtocolClient v err msg))
     runClient (port', ATransport t) useHost c = do
       cVar <- newEmptyTMVarIO
-      let tcConfig = (transportClientConfig networkConfig nm useHost useSNI clientALPN) {clientCredentials = serviceCreds <$> serviceCredentials}
+      let tcConfig = (transportClientConfig networkConfig nm useHost useSNI useALPN) {clientCredentials = serviceCreds <$> serviceCredentials}
           socksCreds = clientSocksCredentials networkConfig proxySessTs transportSession
       tId <-
         runTransportClient tcConfig socksCreds useHost port' (Just $ keyHash srv) (client t c cVar)
-          `forkFinally` \_ -> void (atomically . tryPutTMVar cVar $ Left PCENetworkError)
+          `forkFinally` \r ->
+            let err = either toNetworkError (const NEFailedError) r
+             in void $ atomically $ tryPutTMVar cVar $ Left $ PCENetworkError err
       c_ <- netTimeoutInt tcpConnectTimeout nm `timeout` atomically (takeTMVar cVar)
       case c_ of
         Just (Right c') -> mkWeakThreadId tId >>= \tId' -> pure $ Right c' {action = Just tId'}
         Just (Left e) -> pure $ Left e
-        Nothing -> killThread tId $> Left PCENetworkError
+        Nothing -> killThread tId $> Left (PCENetworkError NETimeoutError)
 
     useTransport :: (ServiceName, ATransport 'TClient)
     useTransport = case port srv of
       "" -> case protocolTypeI @(ProtoType msg) of
-        SPSMP | smpWebPort -> ("443", transport @TLS)
+        SPSMP | web -> ("443", transport @TLS)
         _ -> defaultTransport cfg
       p -> (p, transport @TLS)
-      where
-        smpWebPort = case smpWebPortServers of
-          SWPAll -> True
-          SWPPreset -> case srv of
-            ProtocolServer {host = THDomainName h :| _} -> any (`isSuffixOf` h) presetDomains
-            _ -> False
-          SWPOff -> False
+
+    useALPN :: Maybe [ALPN]
+    useALPN = if web then Just [httpALPN11] else clientALPN
+
+    web = useWebPort networkConfig presetDomains srv
 
     client :: forall c. Transport c => TProxy c 'TClient -> PClient v err msg -> TMVar (Either (ProtocolClientError err) (ProtocolClient v err msg)) -> c 'TClient -> IO ()
     client _ c cVar h = do
@@ -709,6 +717,17 @@ getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qS
               Left e -> logError $ "SMP client error: " <> tshow e
               Right _ -> logWarn "SMP client unprocessed event"
 
+useWebPort :: NetworkConfig -> [HostName] -> ProtocolServer p -> Bool
+useWebPort cfg presetDomains ProtocolServer {host = h :| _} = case smpWebPortServers cfg of
+  SWPAll -> True
+  SWPPreset -> isPresetDomain presetDomains h
+  SWPOff -> False
+
+isPresetDomain :: [HostName] -> TransportHost -> Bool
+isPresetDomain presetDomains = \case
+  THDomainName h -> any (`isSuffixOf` h) presetDomains
+  _ -> False
+
 unexpectedResponse :: Show r => r -> ProtocolClientError err
 unexpectedResponse = PCEUnexpectedResponse . B.pack . take 32 . show
 
@@ -735,7 +754,7 @@ data ProtocolClientError err
     PCEResponseTimeout
   | -- | Failure to establish TCP connection.
     -- Forwarded to the agent client as `ERR BROKER NETWORK`.
-    PCENetworkError
+    PCENetworkError NetworkError
   | -- | No host compatible with network configuration
     PCEIncompatibleHost
   | -- | Service is unavailable for command that requires service connection
@@ -753,7 +772,7 @@ type SMPClientError = ProtocolClientError ErrorType
 
 temporaryClientError :: ProtocolClientError err -> Bool
 temporaryClientError = \case
-  PCENetworkError -> True
+  PCENetworkError _ -> True
   PCEResponseTimeout -> True
   PCEIOError _ -> True
   _ -> False
@@ -774,13 +793,19 @@ smpProxyError = \case
   PCEResponseError e -> PROXY $ BROKER $ RESPONSE $ B.unpack $ strEncode e
   PCEUnexpectedResponse e -> PROXY $ BROKER $ UNEXPECTED $ B.unpack e
   PCEResponseTimeout -> PROXY $ BROKER TIMEOUT
-  PCENetworkError -> PROXY $ BROKER NETWORK
+  PCENetworkError e -> PROXY $ BROKER $ NETWORK e
   PCEIncompatibleHost -> PROXY $ BROKER HOST
   PCEServiceUnavailable -> PROXY $ BROKER $ NO_SERVICE -- for completeness, it cannot happen.
   PCETransportError t -> PROXY $ BROKER $ TRANSPORT t
   PCECryptoError _ -> CRYPTO
   PCEIOError _ -> INTERNAL
 
+smpErrorClientNotice :: SMPClientError -> Maybe (Maybe ClientNotice)
+smpErrorClientNotice = \case
+  PCEProtocolError (BLOCKED BlockingInfo {notice}) -> Just notice
+  _ -> Nothing
+{-# INLINE smpErrorClientNotice #-}
+
 -- | Create a new SMP queue.
 --
 -- https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#create-queue-command
@@ -914,12 +939,12 @@ secureSMPQueue c nm rpKey rId senderKey = okSMPCommand (KEY senderKey) c nm rpKe
 {-# INLINE secureSMPQueue #-}
 
 -- | Secure the SMP queue via sender queue ID.
-secureSndSMPQueue :: SMPClient -> NetworkRequestMode -> SndPrivateAuthKey -> SenderId -> SndPublicAuthKey -> ExceptT SMPClientError IO ()
-secureSndSMPQueue c nm spKey sId senderKey = okSMPCommand (SKEY senderKey) c nm spKey sId
+secureSndSMPQueue :: SMPClient -> NetworkRequestMode -> SndPrivateAuthKey -> SenderId -> ExceptT SMPClientError IO ()
+secureSndSMPQueue c nm spKey sId = okSMPCommand (SKEY $ C.toPublic spKey) c nm spKey sId
 {-# INLINE secureSndSMPQueue #-}
 
-proxySecureSndSMPQueue :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> SndPrivateAuthKey -> SenderId -> SndPublicAuthKey -> ExceptT SMPClientError IO (Either ProxyClientError ())
-proxySecureSndSMPQueue c nm proxiedRelay spKey sId senderKey = proxyOKSMPCommand c nm proxiedRelay (Just spKey) sId (SKEY senderKey)
+proxySecureSndSMPQueue :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> SndPrivateAuthKey -> SenderId -> ExceptT SMPClientError IO (Either ProxyClientError ())
+proxySecureSndSMPQueue c nm proxiedRelay spKey sId = proxyOKSMPCommand c nm proxiedRelay (Just spKey) sId (SKEY $ C.toPublic spKey)
 {-# INLINE proxySecureSndSMPQueue #-}
 
 -- | Add or update date for queue link
@@ -933,15 +958,15 @@ deleteSMPQueueLink = okSMPCommand LDEL
 {-# INLINE deleteSMPQueueLink #-}
 
 -- | Get 1-time inviation SMP queue link data and secure the queue via queue link ID.
-secureGetSMPQueueLink :: SMPClient -> NetworkRequestMode -> SndPrivateAuthKey -> LinkId -> SndPublicAuthKey -> ExceptT SMPClientError IO (SenderId, QueueLinkData)
-secureGetSMPQueueLink c nm spKey lnkId senderKey =
-  sendSMPCommand c nm (Just spKey) lnkId (LKEY senderKey) >>= \case
+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
     LNK sId d -> pure (sId, d)
     r -> throwE $ unexpectedResponse r
 
-proxySecureGetSMPQueueLink :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> SndPrivateAuthKey -> LinkId -> SndPublicAuthKey -> ExceptT SMPClientError IO (Either ProxyClientError (SenderId, QueueLinkData))
-proxySecureGetSMPQueueLink c nm proxiedRelay spKey lnkId senderKey =
-  proxySMPCommand  c nm proxiedRelay (Just spKey) lnkId (LKEY senderKey) >>= \case
+proxySecureGetSMPQueueLink :: SMPClient -> NetworkRequestMode -> ProxiedRelay -> SndPrivateAuthKey -> LinkId -> ExceptT SMPClientError IO (Either ProxyClientError (SenderId, QueueLinkData))
+proxySecureGetSMPQueueLink c nm proxiedRelay spKey lnkId =
+  proxySMPCommand  c nm proxiedRelay (Just spKey) lnkId (LKEY $ C.toPublic spKey) >>= \case
     Right (LNK sId d) -> pure $ Right (sId, d)
     Right r -> throwE $ unexpectedResponse r
     Left e -> pure $ Left e

src/Simplex/Messaging/Client/Agent.hs

@@ -391,7 +391,7 @@ withSMP ca srv action = (getSMPServerClient' ca srv >>= action) `catchE` logSMPE
   where
     logSMPError :: SMPClientError -> ExceptT SMPClientError IO a
     logSMPError e = do
-      logInfo $ "SMP error (" <> safeDecodeUtf8 (strEncode $ host srv) <> "): " <> tshow e
+      logInfo $ "SMP error (" <> safeDecodeUtf8 (strEncode srv) <> "): " <> tshow e
       throwE e
 
 subscribeQueuesNtfs :: SMPClientAgent 'NotifierService -> SMPServer -> NonEmpty (NotifierId, NtfPrivateAuthKey) -> IO ()

src/Simplex/Messaging/Compression.hs

@@ -1,7 +1,11 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.Messaging.Compression where
+module Simplex.Messaging.Compression
+  ( Compressed,
+    maxLengthPassthrough,
+    compressionLevel,
+  ) where
 
 import qualified Codec.Compression.Zstd as Z1
 import Data.ByteString (ByteString)
@@ -36,10 +40,12 @@ compress1 bs
   | B.length bs <= maxLengthPassthrough = Passthrough bs
   | otherwise = Compressed . Large $ Z1.compress compressionLevel bs
 
-decompress1 :: Compressed -> Either String ByteString
-decompress1 = \case
+decompress1 :: Int -> Compressed -> Either String ByteString
+decompress1 limit = \case
   Passthrough bs -> Right bs
-  Compressed (Large bs) -> case Z1.decompress bs of
-    Z1.Error e -> Left e
-    Z1.Skip -> Right mempty
-    Z1.Decompress 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

src/Simplex/Messaging/Crypto.hs

@@ -76,6 +76,7 @@ module Simplex.Messaging.Crypto
     generateKeyPair,
     generateSignatureKeyPair,
     generateAuthKeyPair,
+    generatePrivateAuthKey,
     generateDhKeyPair,
     privateToX509,
     x509ToPublic,
@@ -329,10 +330,10 @@ type PublicKeyX448 = PublicKey X448
 
 -- | GADT for private keys.
 data PrivateKey (a :: Algorithm) where
-  PrivateKeyEd25519 :: Ed25519.SecretKey -> Ed25519.PublicKey -> PrivateKey Ed25519
-  PrivateKeyEd448 :: Ed448.SecretKey -> Ed448.PublicKey -> PrivateKey Ed448
-  PrivateKeyX25519 :: X25519.SecretKey -> X25519.PublicKey -> PrivateKey X25519
-  PrivateKeyX448 :: X448.SecretKey -> X448.PublicKey -> PrivateKey X448
+  PrivateKeyEd25519 :: Ed25519.SecretKey -> PrivateKey Ed25519
+  PrivateKeyEd448 :: Ed448.SecretKey -> PrivateKey Ed448
+  PrivateKeyX25519 :: X25519.SecretKey -> PrivateKey X25519
+  PrivateKeyX448 :: X448.SecretKey -> PrivateKey X448
 
 deriving instance Eq (PrivateKey a)
 
@@ -616,48 +617,66 @@ class CryptoPrivateKey pk where
   type PublicKeyType pk
   toPrivKey :: (forall a. AlgorithmI a => PrivateKey a -> b) -> pk -> b
   privKey :: APrivateKey -> Either String pk
+  toPublic :: pk -> PublicKeyType pk
 
 instance CryptoPrivateKey APrivateKey where
   type PublicKeyType APrivateKey = APublicKey
   toPrivKey f (APrivateKey _ k) = f k
+  {-# INLINE toPrivKey #-}
   privKey = Right
+  {-# INLINE privKey #-}
+  toPublic (APrivateKey a k) = APublicKey a (toPublic k)
+  {-# INLINE toPublic #-}
 
 instance CryptoPrivateKey APrivateSignKey where
   type PublicKeyType APrivateSignKey = APublicVerifyKey
   toPrivKey f (APrivateSignKey _ k) = f k
+  {-# INLINE toPrivKey #-}
   privKey (APrivateKey a k) = case signatureAlgorithm a of
     Just Dict -> Right $ APrivateSignKey a k
     _ -> Left "key does not support signature algorithms"
+  toPublic (APrivateSignKey a k) = APublicVerifyKey a (toPublic k)
+  {-# INLINE toPublic #-}
 
 instance CryptoPrivateKey APrivateAuthKey where
   type PublicKeyType APrivateAuthKey = APublicAuthKey
   toPrivKey f (APrivateAuthKey _ k) = f k
+  {-# INLINE toPrivKey #-}
   privKey (APrivateKey a k) = case authAlgorithm a of
     Just Dict -> Right $ APrivateAuthKey a k
     _ -> Left "key does not support auth algorithms"
+  toPublic (APrivateAuthKey a k) = APublicAuthKey a (toPublic k)
+  {-# INLINE toPublic #-}
 
 instance CryptoPrivateKey APrivateDhKey where
   type PublicKeyType APrivateDhKey = APublicDhKey
   toPrivKey f (APrivateDhKey _ k) = f k
+  {-# INLINE toPrivKey #-}
   privKey (APrivateKey a k) = case dhAlgorithm a of
     Just Dict -> Right $ APrivateDhKey a k
     _ -> Left "key does not support DH algorithm"
+  toPublic (APrivateDhKey a k) = APublicDhKey a (toPublic k)
+  {-# INLINE toPublic #-}
 
 instance AlgorithmI a => CryptoPrivateKey (PrivateKey a) where
   type PublicKeyType (PrivateKey a) = PublicKey a
   toPrivKey = id
+  {-# INLINE toPrivKey #-}
   privKey (APrivateKey _ k) = checkAlgorithm k
+  {-# INLINE privKey #-}
+  toPublic = publicKey
+  {-# INLINE toPublic #-}
 
 publicKey :: PrivateKey a -> PublicKey a
 publicKey = \case
-  PrivateKeyEd25519 _ k -> PublicKeyEd25519 k
-  PrivateKeyEd448 _ k -> PublicKeyEd448 k
-  PrivateKeyX25519 _ k -> PublicKeyX25519 k
-  PrivateKeyX448 _ k -> PublicKeyX448 k
+  PrivateKeyEd25519 pk -> PublicKeyEd25519 (Ed25519.toPublic pk)
+  PrivateKeyEd448 pk -> PublicKeyEd448 (Ed448.toPublic pk)
+  PrivateKeyX25519 pk -> PublicKeyX25519 (X25519.toPublic pk)
+  PrivateKeyX448 pk -> PublicKeyX448 (X448.toPublic pk)
 
 -- | Expand signature private key to a key pair.
 signatureKeyPair :: APrivateSignKey -> ASignatureKeyPair
-signatureKeyPair ak@(APrivateSignKey a k) = (APublicVerifyKey a (publicKey k), ak)
+signatureKeyPair ak@(APrivateSignKey a k) = (APublicVerifyKey a (toPublic k), ak)
 
 encodePrivKey :: CryptoPrivateKey pk => pk -> ByteString
 encodePrivKey = toPrivKey $ encodeASNObj . privateToX509
@@ -707,6 +726,9 @@ generateSignatureKeyPair a g = bimap (APublicVerifyKey a) (APrivateSignKey a) <$
 generateAuthKeyPair :: (AlgorithmI a, AuthAlgorithm a) => SAlgorithm a -> TVar ChaChaDRG -> STM AAuthKeyPair
 generateAuthKeyPair a g = bimap (APublicAuthKey a) (APrivateAuthKey a) <$> generateKeyPair g
 
+generatePrivateAuthKey :: (AlgorithmI a, AuthAlgorithm a) => SAlgorithm a -> TVar ChaChaDRG -> STM APrivateAuthKey
+generatePrivateAuthKey a g = APrivateAuthKey a <$> generatePrivateKey g
+
 generateDhKeyPair :: (AlgorithmI a, DhAlgorithm a) => SAlgorithm a -> TVar ChaChaDRG -> STM ADhKeyPair
 generateDhKeyPair a g = bimap (APublicDhKey a) (APrivateDhKey a) <$> generateKeyPair g
 
@@ -714,23 +736,19 @@ generateKeyPair :: forall a. AlgorithmI a => TVar ChaChaDRG -> STM (KeyPair a)
 generateKeyPair g = stateTVar g (`withDRG` generateKeyPair_)
 
 generateKeyPair_ :: forall a. AlgorithmI a => MonadPseudoRandom ChaChaDRG (KeyPair a)
-generateKeyPair_ = case sAlgorithm @a of
-  SEd25519 ->
-    Ed25519.generateSecretKey >>= \pk ->
-      let k = Ed25519.toPublic pk
-       in pure (PublicKeyEd25519 k, PrivateKeyEd25519 pk k)
-  SEd448 ->
-    Ed448.generateSecretKey >>= \pk ->
-      let k = Ed448.toPublic pk
-       in pure (PublicKeyEd448 k, PrivateKeyEd448 pk k)
-  SX25519 ->
-    X25519.generateSecretKey >>= \pk ->
-      let k = X25519.toPublic pk
-       in pure (PublicKeyX25519 k, PrivateKeyX25519 pk k)
-  SX448 ->
-    X448.generateSecretKey >>= \pk ->
-      let k = X448.toPublic pk
-       in pure (PublicKeyX448 k, PrivateKeyX448 pk k)
+generateKeyPair_ = do
+  pk <- generatePrivateKey_
+  pure (toPublic pk, pk)
+
+generatePrivateKey :: forall a. AlgorithmI a => TVar ChaChaDRG -> STM (PrivateKey a)
+generatePrivateKey g = stateTVar g (`withDRG` generatePrivateKey_)
+
+generatePrivateKey_ :: forall a. AlgorithmI a => MonadPseudoRandom ChaChaDRG (PrivateKey a)
+generatePrivateKey_ = case sAlgorithm @a of
+  SEd25519 -> PrivateKeyEd25519 <$> Ed25519.generateSecretKey
+  SEd448 -> PrivateKeyEd448 <$> Ed448.generateSecretKey
+  SX25519 -> PrivateKeyX25519 <$> X25519.generateSecretKey
+  SX448 -> PrivateKeyX448 <$> X448.generateSecretKey
 
 instance ToField APrivateSignKey where toField = toField . Binary . encodePrivKey
 
@@ -854,8 +872,8 @@ instance SignatureSize APublicVerifyKey where
 
 instance SignatureAlgorithm a => SignatureSize (PrivateKey a) where
   signatureSize = \case
-    PrivateKeyEd25519 _ _ -> Ed25519.signatureSize
-    PrivateKeyEd448 _ _ -> Ed448.signatureSize
+    PrivateKeyEd25519 _ -> Ed25519.signatureSize
+    PrivateKeyEd448 _ -> Ed448.signatureSize
   {-# INLINE signatureSize #-}
 
 instance SignatureAlgorithm a => SignatureSize (PublicKey a) where
@@ -1155,8 +1173,8 @@ cryptoFailable = liftEither . first AESCipherError . CE.eitherCryptoError
 --
 -- Used by SMP clients to sign SMP commands and by SMP agents to sign messages.
 sign' :: SignatureAlgorithm a => PrivateKey a -> ByteString -> Signature a
-sign' (PrivateKeyEd25519 pk k) msg = SignatureEd25519 $ Ed25519.sign pk k msg
-sign' (PrivateKeyEd448 pk k) msg = SignatureEd448 $ Ed448.sign pk k msg
+sign' (PrivateKeyEd25519 pk) msg = SignatureEd25519 $ Ed25519.sign pk (Ed25519.toPublic pk) msg
+sign' (PrivateKeyEd448 pk) msg = SignatureEd448 $ Ed448.sign pk (Ed448.toPublic pk) msg
 {-# INLINE sign' #-}
 
 sign :: APrivateSignKey -> ByteString -> ASignature
@@ -1260,8 +1278,8 @@ verify (APublicVerifyKey a k) (ASignature a' sig) msg = case testEquality a a' o
   _ -> False
 
 dh' :: DhAlgorithm a => PublicKey a -> PrivateKey a -> DhSecret a
-dh' (PublicKeyX25519 k) (PrivateKeyX25519 pk _) = DhSecretX25519 $ X25519.dh k pk
-dh' (PublicKeyX448 k) (PrivateKeyX448 pk _) = DhSecretX448 $ X448.dh k pk
+dh' (PublicKeyX25519 k) (PrivateKeyX25519 pk) = DhSecretX25519 $ X25519.dh k pk
+dh' (PublicKeyX448 k) (PrivateKeyX448 pk) = DhSecretX448 $ X448.dh k pk
 {-# INLINE dh' #-}
 
 -- | NaCl @crypto_box@ encrypt with padding with a shared DH secret and 192-bit nonce.
@@ -1465,10 +1483,10 @@ publicToX509 = \case
 
 privateToX509 :: PrivateKey a -> X.PrivKey
 privateToX509 = \case
-  PrivateKeyEd25519 k _ -> X.PrivKeyEd25519 k
-  PrivateKeyEd448 k _ -> X.PrivKeyEd448 k
-  PrivateKeyX25519 k _ -> X.PrivKeyX25519 k
-  PrivateKeyX448 k _ -> X.PrivKeyX448 k
+  PrivateKeyEd25519 k -> X.PrivKeyEd25519 k
+  PrivateKeyEd448 k -> X.PrivKeyEd448 k
+  PrivateKeyX25519 k -> X.PrivKeyX25519 k
+  PrivateKeyX448 k -> X.PrivKeyX448 k
 
 encodeASNObj :: ASN1Object a => a -> ByteString
 encodeASNObj k = toStrict . encodeASN1 DER $ toASN1 k []
@@ -1495,10 +1513,10 @@ x509ToPublic' k = x509ToPublic (k, []) >>= pubKey
 
 x509ToPrivate :: (X.PrivKey, [ASN1]) -> Either String APrivateKey
 x509ToPrivate = \case
-  (X.PrivKeyEd25519 k, []) -> Right . APrivateKey SEd25519 . PrivateKeyEd25519 k $ Ed25519.toPublic k
-  (X.PrivKeyEd448 k, []) -> Right . APrivateKey SEd448 . PrivateKeyEd448 k $ Ed448.toPublic k
-  (X.PrivKeyX25519 k, []) -> Right . APrivateKey SX25519 . PrivateKeyX25519 k $ X25519.toPublic k
-  (X.PrivKeyX448 k, []) -> Right . APrivateKey SX448 . PrivateKeyX448 k $ X448.toPublic k
+  (X.PrivKeyEd25519 k, []) -> Right $ APrivateKey SEd25519 $ PrivateKeyEd25519 k
+  (X.PrivKeyEd448 k, []) -> Right $ APrivateKey SEd448 $ PrivateKeyEd448 k
+  (X.PrivKeyX25519 k, []) -> Right $ APrivateKey SX25519 $ PrivateKeyX25519 k
+  (X.PrivKeyX448 k, []) -> Right $ APrivateKey SX448 $ PrivateKeyX448 k
   r -> keyError r
 
 x509ToPrivate' :: CryptoPrivateKey k => X.PrivKey -> Either String k

src/Simplex/Messaging/Crypto/SNTRUP761.hs

@@ -2,7 +2,12 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE LambdaCase #-}
 
-module Simplex.Messaging.Crypto.SNTRUP761 where
+module Simplex.Messaging.Crypto.SNTRUP761
+  ( KEMHybridSecret (..),
+    kcbDecrypt,
+    kcbEncrypt,
+    kemHybridSecret,
+  ) where
 
 import Crypto.Hash (Digest, SHA3_256, hash)
 import Data.ByteArray (ScrubbedBytes)

src/Simplex/Messaging/Crypto/SNTRUP761/Bindings.hs

@@ -1,7 +1,16 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TypeApplications #-}
 
-module Simplex.Messaging.Crypto.SNTRUP761.Bindings where
+module Simplex.Messaging.Crypto.SNTRUP761.Bindings
+  ( KEMPublicKey (..),
+    KEMSecretKey,
+    KEMCiphertext (..),
+    KEMSharedKey (..),
+    KEMKeyPair,
+    sntrup761Keypair,
+    sntrup761Enc,
+    sntrup761Dec,
+  ) where
 
 import Control.Concurrent.STM
 import Crypto.Random (ChaChaDRG)

src/Simplex/Messaging/Crypto/ShortLink.hs

@@ -1,6 +1,7 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE GADTs #-}
+{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE MultiWayIf #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
@@ -12,7 +13,9 @@ module Simplex.Messaging.Crypto.ShortLink
   ( contactShortLinkKdf,
     invShortLinkKdf,
     encodeSignLinkData,
+    encodeSignFixedData,
     encodeSignUserData,
+    newOwnerAuth,
     encryptLinkData,
     encryptUserData,
     decryptLinkData,
@@ -20,6 +23,7 @@ module Simplex.Messaging.Crypto.ShortLink
 where
 
 import Control.Concurrent.STM
+import Control.Monad (unless)
 import Control.Monad.Except
 import Control.Monad.IO.Class
 import Crypto.Random (ChaChaDRG)
@@ -31,7 +35,7 @@ import Simplex.Messaging.Agent.Client (cryptoError)
 import Simplex.Messaging.Agent.Protocol
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
-import Simplex.Messaging.Protocol (EntityId (..), LinkId, EncDataBytes (..), QueueLinkData)
+import Simplex.Messaging.Protocol (EncDataBytes (..), EntityId (..), LinkId, QueueLinkData)
 import Simplex.Messaging.Util (liftEitherWith)
 
 fixedDataPaddedLength :: Int
@@ -48,24 +52,37 @@ contactShortLinkKdf (LinkKey k) =
 invShortLinkKdf :: LinkKey -> C.SbKey
 invShortLinkKdf (LinkKey k) = C.unsafeSbKey $ C.hkdf "" k "SimpleXInvLink" 32
 
-encodeSignLinkData :: forall c. ConnectionModeI c => C.KeyPairEd25519 -> VersionRangeSMPA -> ConnectionRequestUri c -> UserLinkData -> (LinkKey, (ByteString, ByteString))
-encodeSignLinkData (rootKey, pk) agentVRange connReq userData =
-  let fd = smpEncode FixedLinkData {agentVRange, rootKey, connReq}
-      md = smpEncode $ connLinkData @c agentVRange userData
-   in (LinkKey (C.sha3_256 fd), (encodeSign pk fd, encodeSign pk md))
+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
+      md = encodeSignUserData (sConnectionMode @c) pk agentVRange userData
+   in (linkKey, (fd, md))
 
-encodeSignUserData :: forall c. ConnectionModeI c => SConnectionMode c -> C.PrivateKeyEd25519 -> VersionRangeSMPA -> UserLinkData -> ByteString
-encodeSignUserData _ pk agentVRange userData =
-  encodeSign pk $ smpEncode $ connLinkData @c agentVRange userData
+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}
+   in (LinkKey (C.sha3_256 fd), encodeSign pk fd)
 
-connLinkData :: forall c. ConnectionModeI c => VersionRangeSMPA -> UserLinkData -> ConnLinkData c
-connLinkData agentVRange userData = case sConnectionMode @c of
-  SCMInvitation -> InvitationLinkData agentVRange userData
-  SCMContact -> ContactLinkData {agentVRange, direct = True, owners = [], relays = [], userData}
+encodeSignUserData :: ConnectionModeI c => SConnectionMode c -> C.PrivateKeyEd25519 -> VersionRangeSMPA -> UserConnLinkData c -> ByteString
+encodeSignUserData _ pk agentVRange userLinkData =
+  encodeSign pk $ smpEncode $ connLinkData agentVRange userLinkData
+
+connLinkData :: VersionRangeSMPA -> UserConnLinkData c -> ConnLinkData c
+connLinkData vr = \case
+  UserInvLinkData d -> InvitationLinkData vr d
+  UserContactLinkData d -> ContactLinkData vr d
 
 encodeSign :: C.PrivateKeyEd25519 -> ByteString -> ByteString
 encodeSign pk s = smpEncode (C.sign' pk s) <> s
 
+-- | Generate a new owner key pair and create OwnerAuth signed by the authorizing key.
+-- ownerId is application-specific (e.g., MemberId in chat).
+newOwnerAuth :: TVar ChaChaDRG -> OwnerId -> C.PrivateKeyEd25519 -> IO (C.PrivateKeyEd25519, OwnerAuth)
+newOwnerAuth g ownerId signingKey = do
+  (ownerKey, ownerPrivKey) <- atomically $ C.generateKeyPair @'C.Ed25519 g
+  let authOwnerSig = C.sign' signingKey $ ownerId <> C.encodePubKey ownerKey
+  pure (ownerPrivKey, OwnerAuth {ownerId, ownerKey, authOwnerSig})
+
 encryptLinkData :: TVar ChaChaDRG -> C.SbKey -> (ByteString, ByteString) -> ExceptT AgentErrorType IO QueueLinkData
 encryptLinkData g k = bimapM (encrypt fixedDataPaddedLength) (encrypt userDataPaddedLength)
   where
@@ -80,17 +97,22 @@ encryptData g k len s = do
   ct <- liftEitherWith cryptoError $ C.sbEncrypt k nonce s len
   pure $ EncDataBytes $ smpEncode nonce <> ct
 
-decryptLinkData :: forall c. ConnectionModeI c => LinkKey -> C.SbKey -> QueueLinkData -> Either AgentErrorType (ConnectionRequestUri c, ConnLinkData c)
+decryptLinkData :: forall c. ConnectionModeI c => LinkKey -> C.SbKey -> QueueLinkData -> Either AgentErrorType (FixedLinkData c, ConnLinkData c)
 decryptLinkData linkKey k (encFD, encMD) = do
   (sig1, fd) <- decrypt encFD
   (sig2, md) <- decrypt encMD
-  FixedLinkData {rootKey, connReq} <- decode fd
+  fd'@FixedLinkData {rootKey} <- decode fd
   md' <- decode @(ConnLinkData c) md
+  let signedBy k' = C.verify' k' sig2 md
   if
     | LinkKey (C.sha3_256 fd) /= linkKey -> linkErr "link data hash"
     | not (C.verify' rootKey sig1 fd) -> linkErr "link data signature"
-    | not (C.verify' rootKey sig2 md) -> linkErr "user data signature"
-    | otherwise -> Right (connReq, md')
+    | otherwise -> case md' of
+        InvitationLinkData {} -> unless (signedBy rootKey) $ linkErr "user data signature"
+        ContactLinkData _ UserContactData {owners} -> do
+          first (AGENT . A_LINK) $ validateLinkOwners rootKey owners
+          unless (signedBy rootKey || any (signedBy . ownerKey) owners) $ linkErr "user data signature"
+  Right (fd', md')
   where
     decrypt (EncDataBytes d) = do
       (nonce, Tail ct) <- decode d
@@ -99,4 +121,5 @@ decryptLinkData linkKey k (encFD, encMD) = do
     decode :: Encoding a => ByteString -> Either AgentErrorType a
     decode = msgErr . smpDecode
     msgErr = first (const $ AGENT A_MESSAGE)
+    linkErr :: String -> Either AgentErrorType ()
     linkErr = Left . AGENT . A_LINK

src/Simplex/Messaging/Encoding.hs

@@ -24,6 +24,8 @@ import Data.Bits (shiftL, shiftR, (.|.))
 import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.ByteString.Internal (c2w, w2c)
+import Data.Text (Text)
+import Data.Text.Encoding (decodeUtf8', encodeUtf8)
 import Data.Int (Int64)
 import qualified Data.List.NonEmpty as L
 import Data.Time.Clock.System (SystemTime (..))
@@ -156,6 +158,12 @@ smpEncodeList xs = B.cons (lenEncode $ length xs) . B.concat $ map smpEncode xs
 smpListP :: Encoding a => Parser [a]
 smpListP = (`A.count` smpP) =<< lenP
 
+instance Encoding Text where
+  smpEncode = smpEncode . encodeUtf8
+  {-# INLINE smpEncode #-}
+  smpP = either (fail . show) pure . decodeUtf8' =<< smpP
+  {-# INLINE smpP #-}
+
 instance Encoding String where
   smpEncode = smpEncode . B.pack
   {-# INLINE smpEncode #-}

src/Simplex/Messaging/Encoding/String.hs

@@ -10,6 +10,9 @@ module Simplex.Messaging.Encoding.String
     strToJSON,
     strToJEncoding,
     strParseJSON,
+    textToJSON,
+    textToEncoding,
+    textParseJSON,
     base64urlP,
     strEncodeList,
     strListP,
@@ -225,9 +228,22 @@ _strP = A.space *> strP
 
 strToJSON :: StrEncoding a => a -> J.Value
 strToJSON = J.String . decodeLatin1 . strEncode
+{-# INLINE strToJSON #-}
 
 strToJEncoding :: StrEncoding a => a -> J.Encoding
 strToJEncoding = JE.text . decodeLatin1 . strEncode
+{-# INLINE strToJEncoding #-}
 
 strParseJSON :: StrEncoding a => String -> J.Value -> JT.Parser a
 strParseJSON name = J.withText name $ either fail pure . parseAll strP . encodeUtf8
+
+textToJSON :: TextEncoding a => a -> J.Value
+textToJSON = J.String . textEncode
+{-# INLINE textToJSON #-}
+
+textToEncoding :: TextEncoding a => a -> J.Encoding
+textToEncoding = JE.text . textEncode
+{-# INLINE textToEncoding #-}
+
+textParseJSON :: TextEncoding a => String -> J.Value -> JT.Parser a
+textParseJSON name = J.withText name $ maybe (fail name) pure . textDecode

src/Simplex/Messaging/Notifications/Client.hs

@@ -4,7 +4,25 @@
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE TypeApplications #-}
 
-module Simplex.Messaging.Notifications.Client where
+module Simplex.Messaging.Notifications.Client
+  ( NtfClient,
+    NtfClientError,
+    defaultNTFClientConfig,
+    ntfRegisterToken,
+    ntfVerifyToken,
+    ntfCheckToken,
+    ntfReplaceToken,
+    ntfDeleteToken,
+    ntfSetCronInterval,
+    ntfCreateSubscription,
+    ntfCreateSubscriptions,
+    ntfCheckSubscription,
+    ntfCheckSubscriptions,
+    ntfDeleteSubscription,
+    sendNtfCommand,
+    okNtfCommand,
+  )
+where
 
 import Control.Monad.Except
 import Control.Monad.Trans.Except

src/Simplex/Messaging/Notifications/Protocol.hs

@@ -9,7 +9,36 @@
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeFamilies #-}
 
-module Simplex.Messaging.Notifications.Protocol where
+module Simplex.Messaging.Notifications.Protocol
+  ( NtfEntity (..),
+    SNtfEntity (..),
+    NtfEntityI (..),
+    NtfCommandTag (..),
+    NtfCmdTag (..),
+    NtfRegCode (..),
+    NewNtfEntity (..),
+    ANewNtfEntity (..),
+    NtfCommand (..),
+    NtfCmd (..),
+    NtfResponseTag (..),
+    NtfResponse (..),
+    SMPQueueNtf (..),
+    PushProvider (..),
+    DeviceToken (..),
+    PNMessageData (..),
+    NtfEntityId,
+    NtfSubscriptionId,
+    NtfTokenId,
+    NtfSubStatus (..),
+    NtfTknStatus (..),
+    NTInvalidReason (..),
+    encodePNMessages,
+    pnMessagesP,
+    ntfShouldSubscribe,
+    allowTokenVerification,
+    allowNtfSubCommands,
+    checkEntity,
+  ) where
 
 import Control.Applicative (optional, (<|>))
 import Data.Aeson (FromJSON (..), ToJSON (..), (.:), (.=))

src/Simplex/Messaging/Notifications/Server.hs

@@ -15,7 +15,12 @@
 {-# LANGUAGE TupleSections #-}
 {-# OPTIONS_GHC -fno-warn-ambiguous-fields #-}
 
-module Simplex.Messaging.Notifications.Server where
+module Simplex.Messaging.Notifications.Server
+  ( runNtfServer,
+    runNtfServerBlocking,
+    restoreServerLastNtfs,
+  )
+where
 
 import Control.Concurrent (threadDelay)
 import Control.Concurrent.Async (mapConcurrently)
@@ -67,9 +72,9 @@ import qualified Simplex.Messaging.Protocol as SMP
 import Simplex.Messaging.Server
 import Simplex.Messaging.Server.Control (CPClientRole (..))
 import Simplex.Messaging.Server.Env.STM (StartOptions (..))
-import Simplex.Messaging.Server.QueueStore (getSystemDate)
 import Simplex.Messaging.Server.Stats (PeriodStats (..), PeriodStatCounts (..), periodStatCounts, periodStatDataCounts, updatePeriodStats)
 import Simplex.Messaging.Session
+import Simplex.Messaging.SystemTime
 import Simplex.Messaging.TMap (TMap)
 import Simplex.Messaging.Transport (ASrvTransport, ATransport (..), THandle (..), THandleAuth (..), THandleParams (..), TProxy, Transport (..), TransportPeer (..), defaultSupportedParams)
 import Simplex.Messaging.Transport.Buffer (trimCR)
@@ -613,7 +618,7 @@ ntfSubscriber NtfSubscriber {smpAgent = ca@SMPClientAgent {msgQ, agentQ}} =
       PCEIncompatibleHost -> Just $ NSErr "IncompatibleHost"
       PCEServiceUnavailable -> Just NSService -- this error should not happen on individual subscriptions
       PCEResponseTimeout -> Nothing
-      PCENetworkError -> Nothing
+      PCENetworkError _ -> Nothing
       PCEIOError _ -> Nothing
       where
         -- Note on moving to PostgreSQL: the idea of logging errors without e is removed here

src/Simplex/Messaging/Notifications/Server/Control.hs

@@ -1,7 +1,10 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 
-module Simplex.Messaging.Notifications.Server.Control where
+module Simplex.Messaging.Notifications.Server.Control
+  ( ControlProtocol (..),
+  )
+where
 
 import qualified Data.Attoparsec.ByteString.Char8 as A
 import Simplex.Messaging.Encoding.String