diff --git a/.github/workflows/desktop-linux.yml b/.github/workflows/desktop-linux.yml
index fad3c27923..0562f755c9 100644
--- a/.github/workflows/desktop-linux.yml
+++ b/.github/workflows/desktop-linux.yml
@@ -211,8 +211,8 @@ jobs:
       - name: Install tools
         run: |
           sudo apt-get update
-          sudo apt-get install -y xvfb xdotool openbox imagemagick tesseract-ocr sqlite3
-          dpkg-query -W xvfb xdotool openbox imagemagick tesseract-ocr sqlite3
+          sudo apt-get install -y xvfb xdotool openbox imagemagick tesseract-ocr sqlite3 fonts-dejavu-core
+          dpkg-query -W xvfb xdotool openbox imagemagick tesseract-ocr sqlite3 fonts-dejavu-core
 
       - name: Download core library
         uses: actions/download-artifact@v7
@@ -275,7 +275,9 @@ jobs:
 
       - name: Run smoke test
         if: ${{ !cancelled() && steps.build.outcome == 'success' && steps.link.outcome == 'success' }}
-        run: scripts/ci/desktop-linux/smoke-test.sh apps/multiplatform/release/main/app/simplex "$RUNNER_TEMP/smoke-test"
+        run: |
+          export NAMES_SERVER=$(cat "$RUNNER_TEMP/backend/names-server")
+          scripts/ci/desktop-linux/smoke-test.sh apps/multiplatform/release/main/app/simplex "$RUNNER_TEMP/smoke-test"
 
       - name: Stop test backend
         if: ${{ !cancelled() }}
diff --git a/scripts/ci/desktop-linux/backend.sh b/scripts/ci/desktop-linux/backend.sh
index 2c1225de83..75f6da24ff 100755
--- a/scripts/ci/desktop-linux/backend.sh
+++ b/scripts/ci/desktop-linux/backend.sh
@@ -4,13 +4,17 @@
 # and one channel registered and approved by a CLI peer, and a search request that must find both.
 # Both have profile images as large as the apps make them, so their search results don't fit in one service
 # response, and the search must page through them.
+# For SimpleX names, an SMP server on 127.0.0.1 resolves .testing names through a local resolver, and a CLI peer
+# with an address on it claims the name seeded.testing.
 # Usage:
 #   scripts/ci/desktop-linux/backend.sh start <backend .tar.gz> <work dir>   writes the directory's short address to <work dir>/directory-link
-#   scripts/ci/desktop-linux/backend.sh stop <work dir>                      stops the relay and the directory, prints their logs
-# The relay and the directory keep running between start and stop.
+#                                                                            and the names server's address to <work dir>/names-server
+#   scripts/ci/desktop-linux/backend.sh stop <work dir>                      stops the servers, prints their logs
+# The relay, the directory, the SMP server and the resolver keep running between start and stop.
 
 set -euo pipefail
 
+here=$(cd "$(dirname "$0")" && pwd)
 directory_name="SimpleX Directory"
 admin=ci_admin
 search_text="ci seed"
@@ -18,8 +22,8 @@ search_text="ci seed"
 max_image_size=12500
 # the largest service response body, compressed if it has to be (maxServiceBodyLength)
 max_service_body=10737
-group_colour="rgb(200,40,40)"
-channel_colour="rgb(40,170,60)"
+name_label=seeded
+resolver_port=8090
 
 # Runs one chat command in a CLI client that stays online for <secs> after it; the output is in $work/out.
 chat() {
@@ -63,18 +67,21 @@ db_query() {
 }
 
 # Prints a profile image data URI made as the apps make one: JPEG at quality 85, scaled down by the square root
-# of its excess, at most halved per step, until it is at most max_image_size characters. The source is noise
-# over the colour, which JPEG can't compress much, so the image ends up near the limit.
+# of its excess, at most halved per step, until it is at most max_image_size characters. The picture fills the
+# whole square, a gradient between two shades of one colour with a large white letter; noise keeps JPEG from
+# compressing it much, so the image ends up near the limit.
 avatar() {
-  local colour=$1 source=$work/avatar-source.png file=$work/avatar.jpg size=512 uri
-  convert -size 512x512 xc:gray50 -seed 1 +noise Random -modulate 100,0 -fill "$colour" -colorize 70% "$source"
+  local top=$1 bottom=$2 letter=$3 source=$work/avatar-source.png file=$work/avatar.jpg size=512 uri font
+  font=$(fc-match -f '%{file}' 'DejaVu Sans:bold')
+  convert -size 512x512 gradient:"$top-$bottom" -seed 1 -attenuate 0.5 +noise Gaussian \
+    -font "$font" -pointsize 320 -fill white -gravity center -annotate +0+0 "$letter" "$source"
   while :; do
     convert "$source" -resize "${size}x${size}" -quality 85 "$file"
     uri="data:image/jpg;base64,$(base64 -w 0 "$file")"
     [ "${#uri}" -gt "$max_image_size" ] || break
     size=$(awk -v s="$size" -v n="${#uri}" -v m="$max_image_size" 'BEGIN { r = sqrt(n / m); if (r > 2) r = 2; print int(s / r) }')
   done
-  echo "avatar over $colour: ${size}x${size} px, ${#uri} characters, mean colour $(convert "$file" -resize '1x1!' -format '%[pixel:p{0,0}]' info:)" >&2
+  echo "avatar \"$letter\" over $top to $bottom: ${size}x${size} px, ${#uri} characters, mean colour $(convert "$file" -resize '1x1!' -format '%[pixel:p{0,0}]' info:)" >&2
   echo "$uri"
 }
 
@@ -169,9 +176,9 @@ group_json() {
 seed_group() {
   local user_id
   user_id=$(db_query "$admin" "SELECT user_id FROM users WHERE local_display_name = '$admin'")
-  group_image=$(avatar "$group_colour")
-  admin 1 "/_group $user_id $(group_json ci_group "CI seed group" "$group_image" "")"
-  expect_out "group #ci_group \(CI seed group\) is created"
+  group_image=$(avatar "rgb(235,80,70)" "rgb(150,25,30)" G)
+  admin 1 "/_group $user_id $(group_json ci_group "CI seeded group" "$group_image" "")"
+  expect_out "group #ci_group \(CI seeded group\) is created"
   admin 5 "/a ci_group '$directory_name' admin"
   expect_out "invitation to join the group #ci_group sent to"
   approve ci_group "Group approved!"
@@ -183,9 +190,9 @@ seed_channel() {
   local user_id relay_id
   user_id=$(db_query "$admin" "SELECT user_id FROM users WHERE local_display_name = '$admin'")
   relay_id=$(db_query "$admin" "SELECT chat_relay_id FROM chat_relays WHERE display_name = 'ci_relay' AND deleted = 0")
-  channel_image=$(avatar "$channel_colour")
-  admin 10 "/_public group $user_id $relay_id $(group_json ci_channel "CI seed channel" "$channel_image" ",\"support\":{\"enable\":\"off\"}")"
-  expect_out "group #ci_channel \(CI seed channel\) is created"
+  channel_image=$(avatar "rgb(80,200,90)" "rgb(25,120,45)" C)
+  admin 10 "/_public group $user_id $relay_id $(group_json ci_channel "CI seeded channel" "$channel_image" ",\"support\":{\"enable\":\"off\"}")"
+  expect_out "group #ci_channel \(CI seeded channel\) is created"
   local group_id
   group_id=$(db_query "$admin" "SELECT group_id FROM groups WHERE local_display_name = 'ci_channel'")
   admin_until "relay id [0-9]+: active" 180 "/_get relays #$group_id"
@@ -194,6 +201,71 @@ seed_channel() {
   approve ci_channel "Channel approved!"
 }
 
+# An SMP server on 127.0.0.1 whose [NAMES] section asks the local resolver, which answers from names.json.
+start_names_server() {
+  local cfg=$work/smp/etc logs=$work/smp/var ini deadline
+  echo '{}' > "$work/names.json"
+  nohup python3 "$here/names-resolver.py" "$resolver_port" "$work/names.json" < /dev/null > "$work/resolver.log" 2>&1 &
+  echo $! > "$work/resolver.pid"
+  SMP_SERVER_CFG_PATH=$cfg SMP_SERVER_LOG_PATH=$logs "$bin/smp-server" init -y --ip 127.0.0.1 --no-password --disable-web
+  ini=$cfg/smp-server.ini
+  # only 5223: 443 needs root
+  sed -i -e 's/^port = 5223,443$/port = 5223/' \
+    -e '/^\[NAMES\]/,/^\[/{s/^enable: off$/enable: on/;s|^# resolver_endpoint: http://127.0.0.1:8000$|resolver_endpoint: http://127.0.0.1:'"$resolver_port"'|}' "$ini"
+  if ! grep -qx 'port = 5223' "$ini" ||
+    ! sed -n '/^\[NAMES\]/,/^\[/p' "$ini" | grep -qx 'enable: on' ||
+    ! sed -n '/^\[NAMES\]/,/^\[/p' "$ini" | grep -qx "resolver_endpoint: http://127.0.0.1:$resolver_port"; then
+    echo "error: $ini has a different port or [NAMES] than expected:"
+    grep -E '^port|^\[NAMES\]|enable|resolver' "$ini"
+    return 1
+  fi
+  SMP_SERVER_CFG_PATH=$cfg SMP_SERVER_LOG_PATH=$logs nohup "$bin/smp-server" start < /dev/null > "$work/smp-server.log" 2>&1 &
+  echo $! > "$work/smp-server.pid"
+  deadline=$((SECONDS + 60))
+  until (exec 3<> /dev/tcp/127.0.0.1/5223) 2> /dev/null; do
+    if ! kill -0 "$(cat "$work/smp-server.pid")" 2> /dev/null || [ "$SECONDS" -ge "$deadline" ]; then
+      echo "error: the SMP server is not listening on 5223"
+      cat "$work/smp-server.log"
+      return 1
+    fi
+    sleep 1
+  done
+  names_server="smp://$(cat "$cfg/fingerprint")@127.0.0.1"
+  echo "$names_server" > "$work/names-server"
+  echo "names server: $names_server"
+}
+
+# A CLI client started with -s uses only that server and, once its user exists, gives it every role, names included.
+names_client() {
+  local db=$1
+  shift
+  chat "$db" "$@" --user-display-name "$db" -s "$names_server"
+}
+
+# ci_contact's address is on the names server; the resolver maps seeded.testing to it, and ci_contact claims the name.
+seed_name() {
+  local image link
+  image=$(avatar "rgb(70,130,240)" "rgb(30,50,170)" N)
+  names_client ci_contact 1 "/_profile 1 {\"displayName\":\"ci_contact\",\"fullName\":\"\",\"shortDescr\":\"CI seeded contact\",\"image\":\"$image\"}"
+  names_client ci_contact 3 "/ad"
+  link=$(awk '/Your new chat address is created!/ {getline; getline; print; exit}' "$work/out")
+  case "$link" in
+    https://*/a#*) ;;
+    *)
+      echo "error: no short address for ci_contact in the output"
+      return 1
+      ;;
+  esac
+  jq -n --arg n "$name_label" --arg l "$link" '{($n): {simplexContact: [$l]}}' > "$work/names.json"
+  names_client ci_contact 5 "/_set domain 1 $name_label.testing"
+  # what the app does on the Search key, from a client that knows nothing but the names server; it finds the
+  # address only if ci_contact's claim is in the address data
+  names_client name_probe 1 "/user"
+  names_client name_probe 5 "/_connect plan 1 @$name_label.testing"
+  expect_out "contact address: ok to connect"
+  echo "@$name_label.testing resolves to ci_contact's address"
+}
+
 page_summary() {
   local resp=$1 compressed=""
   if command -v zstd > /dev/null; then
@@ -266,17 +338,19 @@ start() {
   seed_group
   seed_channel
   probe_search
+  start_names_server
+  seed_name
 }
 
 stop() {
   local p
-  for p in directory relay; do
+  for p in directory relay smp-server resolver; do
     if [ -f "$work/$p.pid" ]; then
       kill -INT "$(cat "$work/$p.pid")" 2> /dev/null || true
     fi
   done
   sleep 3
-  for p in directory relay; do
+  for p in directory relay smp-server resolver; do
     echo "::group::$p log"
     cat "$work/$p.log" 2> /dev/null || true
     echo "::endgroup::"
diff --git a/scripts/ci/desktop-linux/build-backend.sh b/scripts/ci/desktop-linux/build-backend.sh
index fcc8c08850..9261c56ae1 100755
--- a/scripts/ci/desktop-linux/build-backend.sh
+++ b/scripts/ci/desktop-linux/build-backend.sh
@@ -1,8 +1,10 @@
 #!/bin/bash
 
-# Builds the CLI and the directory service that the app job runs as its test backend.
+# Builds the CLI, the directory service and the SMP server that the app job runs as its test backend.
 # Usage: scripts/ci/desktop-linux/build-backend.sh <output .tar.gz>
 # They need the server-capable configuration (no client_library), as build.yml's Linux job builds the CLI.
+# The SMP server, which resolves the test's SimpleX names, comes from a clone of the simplexmq commit that
+# cabal.project pins: cabal builds only the libraries of a source-repository-package.
 
 set -euo pipefail
 
@@ -23,10 +25,19 @@ EOF
 
 cabal build exe:simplex-chat exe:simplex-directory-service
 
+simplexmq_tag=$(sed -n '/simplex-chat\/simplexmq.git/{n;s/^ *tag: *//p}' cabal.project)
+smq=$(mktemp -d)
+git -C "$smq" init -q
+git -C "$smq" fetch -q --depth 1 https://github.com/simplex-chat/simplexmq.git "$simplexmq_tag"
+git -C "$smq" checkout -q FETCH_HEAD
+cp cabal.project.local "$smq"
+(cd "$smq" && cabal build exe:smp-server)
+
 pkg=$(mktemp -d)
 for exe in simplex-chat simplex-directory-service; do
   cp "$(cabal list-bin "exe:$exe")" "$pkg"
 done
+cp "$(cd "$smq" && cabal list-bin exe:smp-server)" "$pkg"
 ldd "$pkg"/*
 
 tar -C "$pkg" -czf "$out" .
diff --git a/scripts/ci/desktop-linux/names-resolver.py b/scripts/ci/desktop-linux/names-resolver.py
new file mode 100644
index 0000000000..34ff8cfd8b
--- /dev/null
+++ b/scripts/ci/desktop-linux/names-resolver.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+
+# A SimpleX name resolver for the test SMP server's [NAMES] section, as simplexmq's test resolver answers:
+# GET /v2/resolve/<query> with a NameResponse for every name, registered or not, and GET /health.
+# Names are read from the registry file on each request: {"<label>": {"simplexContact": [...], "simplexChannel": [...]}},
+# all under .testing. A v22 router asks by label hash, "[<keccak-256 hex>].testing", so names are matched by hash.
+# Usage: names-resolver.py <port> <registry .json>
+
+import json
+import sys
+from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+from urllib.parse import unquote
+
+MASK = (1 << 64) - 1
+ROTATIONS = [[0, 36, 3, 41, 18], [1, 44, 10, 45, 2], [62, 6, 43, 15, 61], [28, 55, 25, 21, 56], [27, 20, 39, 8, 14]]
+
+
+def round_constants():
+    r, constants = 1, []
+    for _ in range(24):
+        c = 0
+        for j in range(7):
+            if r & 1:
+                c |= 1 << ((1 << j) - 1)
+            r = ((r << 1) ^ 0x71) & 0xFF if r & 0x80 else r << 1
+        constants.append(c)
+    return constants
+
+
+ROUND_CONSTANTS = round_constants()
+
+
+def rotate(x, n):
+    return ((x << n) | (x >> (64 - n))) & MASK if n else x
+
+
+def keccak_f(a):
+    for rc in ROUND_CONSTANTS:
+        c = [a[x][0] ^ a[x][1] ^ a[x][2] ^ a[x][3] ^ a[x][4] for x in range(5)]
+        d = [c[x - 1] ^ rotate(c[(x + 1) % 5], 1) for x in range(5)]
+        a = [[a[x][y] ^ d[x] for y in range(5)] for x in range(5)]
+        b = [[0] * 5 for _ in range(5)]
+        for x in range(5):
+            for y in range(5):
+                b[y][(2 * x + 3 * y) % 5] = rotate(a[x][y], ROTATIONS[x][y])
+        a = [[b[x][y] ^ (~b[(x + 1) % 5][y] & b[(x + 2) % 5][y]) for y in range(5)] for x in range(5)]
+        a[0][0] ^= rc
+    return a
+
+
+# Keccak-256 as Ethereum uses it (padding 0x01, not SHA3-256's 0x06), which labelHash in SimplexName.hs is
+def keccak256(data):
+    rate = 136
+    padded = bytearray(data) + b"\x01" + bytes(-(len(data) + 1) % rate)
+    padded[-1] |= 0x80
+    a = [[0] * 5 for _ in range(5)]
+    for block in range(0, len(padded), rate):
+        for i in range(rate // 8):
+            a[i % 5][i // 5] ^= int.from_bytes(padded[block + 8 * i:block + 8 * i + 8], "little")
+        a = keccak_f(a)
+    return b"".join(a[i % 5][i // 5].to_bytes(8, "little") for i in range(4))
+
+
+def query_key(label):
+    return "[" + keccak256(label.lower().encode()).hex() + "].testing"
+
+
+def record(label, links):
+    return {
+        "name": label + ".testing",
+        "nickname": "",
+        "website": "",
+        "location": "",
+        "simplexContact": links.get("simplexContact", []),
+        "simplexChannel": links.get("simplexChannel", []),
+        "eth": None,
+        "btc": None,
+        "xmr": None,
+        "dot": None,
+        "owner": "",
+        "resolver": "",
+    }
+
+
+def name_response(query, registry_file):
+    with open(registry_file) as f:
+        registry = json.load(f)
+    for label, links in registry.items():
+        if query in (query_key(label), label.lower() + ".testing"):
+            return {"registration": {"type": "registered", "nameRecord": record(label, links)}}
+    return {"registration": {"type": "available", "pricing": {"registrationPrices": {}, "basePrice": 1000, "minLabelLength": 1}}}
+
+
+class Resolver(BaseHTTPRequestHandler):
+    def do_GET(self):
+        prefix = "/v2/resolve/"
+        if self.path == "/health":
+            self.reply(200, {})
+        elif self.path.startswith(prefix):
+            query = unquote(self.path[len(prefix):])
+            response = name_response(query, self.server.registry_file)
+            print(f"resolve {query}: {response['registration']['type']}", flush=True)
+            self.reply(200, response)
+        else:
+            self.reply(404, {})
+
+    def reply(self, status, body):
+        data = json.dumps(body).encode()
+        self.send_response(status)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(data)))
+        self.end_headers()
+        self.wfile.write(data)
+
+
+def main():
+    server = ThreadingHTTPServer(("127.0.0.1", int(sys.argv[1])), Resolver)
+    server.registry_file = sys.argv[2]
+    print(f"names resolver on 127.0.0.1:{sys.argv[1]}, registry {sys.argv[2]}", flush=True)
+    server.serve_forever()
+
+
+if __name__ == "__main__":
+    main()