diff --git a/.env.example b/.env.example
index 3261700..359d681 100644
--- a/.env.example
+++ b/.env.example
@@ -108,6 +108,23 @@ UPLOAD_SPOOL_MAX_AGE_HOURS=72
 UPLOAD_RETRY_MIN_SECONDS=15
 UPLOAD_RETRY_MAX_SECONDS=600
 
+# --- Recorder backend (node-26#45) -------------------------------------------
+# op25 (default): OP25 + PulseAudio recorder, one call at a time.
+# trunk-recorder: Trunk Recorder records every talkgroup at once, with call
+# boundaries from the decoder. Set BOTH lines below to switch; OP25 is then
+# never started (it would hold the SDR), and the live browser stream (Icecast)
+# goes quiet — Discord live audio keeps working.
+RECORDER_BACKEND=op25
+# COMPOSE_PROFILES=trunk-recorder
+# Trunk Recorder SDR settings (only read with RECORDER_BACKEND=trunk-recorder).
+# TR_SAMPLE_RATE=2400000
+# TR_GAIN=34
+# TR_CENTER_HZ=            # override the computed centre frequency
+# TR_DIGITAL_RECORDERS=4   # simultaneous voice channels on a trunked system
+# TR_MIN_DURATION=1.0      # seconds; shorter calls are dropped by TR
+# TR_SQUELCH_DB=-50        # conventional channels; absolute dB, tune per site
+# TR_LIVE_PORT=9123        # local UDP port for simplestream -> Discord
+
 # OP25 container (usually no need to change)
 OP25_API_URL=http://localhost:8001
 OP25_TERMINAL_URL=http://localhost:8081
diff --git a/docker-compose.yml b/docker-compose.yml
index d53de78..35ee3d3 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -51,6 +51,35 @@ services:
     volumes:
       - /dev:/dev
 
+  # Trunk Recorder (node-26#45) — the alternative recorder. Opt-in per node:
+  # it only starts when the node's .env has COMPOSE_PROFILES=trunk-recorder,
+  # and the edge-node only uses it with RECORDER_BACKEND=trunk-recorder. Set
+  # both or neither. Upstream image, pinned by tag AND digest (the digest is
+  # the multi-arch index for 5.2.1 on Docker Hub, amd64/arm64/arm/v7); bump
+  # both together. GPL-3.0: we ship it unmodified as a separate program —
+  # see trunk-recorder/README.md for the source offer.
+  #
+  # The edge-node writes ./configs/trunk-recorder/config.json; run.sh (our
+  # supervisor, replacing the image's CMD) restarts TR when it changes. It
+  # shares OP25's dongle slot, so op25 is never started on such a node.
+  trunk-recorder:
+    image: robotastic/trunk-recorder:5.2.1@sha256:c3e425858bfca16c609d8612808a83f06b0f376d950d11733d7c25b2a28f8866
+    profiles: ["trunk-recorder"]
+    restart: unless-stopped
+    network_mode: host
+    devices:
+      - /dev/bus/usb:/dev/bus/usb
+    # TR stages each transmission in tempDir (/dev/shm); Docker's 64 MB
+    # default is tight with several recorders running at once.
+    shm_size: 256m
+    entrypoint: ["/bin/sh", "/drb/run.sh"]
+    environment:
+      TZ: ${TZ:-UTC}
+    volumes:
+      - ./configs/trunk-recorder:/app
+      - ./recordings:/recordings
+      - ./trunk-recorder:/drb:ro
+
   edge-node:
     image: ${IMAGE_REGISTRY:-git.vpn.cusano.net}/${DOCKER_ORG:-logan}/${DOCKER_REPO:-node-26}/edge-node:${DRB_TAG_EDGE_NODE:-latest}
     build: ./drb-edge-node
diff --git a/trunk-recorder/README.md b/trunk-recorder/README.md
new file mode 100644
index 0000000..2cb7766
--- /dev/null
+++ b/trunk-recorder/README.md
@@ -0,0 +1,34 @@
+# Trunk Recorder on a DRB node (node-26#45)
+
+Opt-in alternative to the OP25 recorder. On a node, set both in `.env`, then
+`docker compose up -d`:
+
+    RECORDER_BACKEND=trunk-recorder
+    COMPOSE_PROFILES=trunk-recorder
+
+Set both back (`RECORDER_BACKEND=op25`, remove `COMPOSE_PROFILES`) to return
+to OP25.
+
+- `run.sh`: supervisor that replaces the image's CMD. It restarts TR when the
+  edge-node rewrites `configs/trunk-recorder/config.json`, and writes
+  `drb-status.json` for the dashboard health check.
+- `drb-upload.sh`: TR's `uploadScript`. It copies each finished call (WAV +
+  JSON) into `recordings/tr-inbox`, where the edge-node uploads it through the
+  normal spool.
+
+## License (GPL-3.0)
+
+Trunk Recorder is GPL-3.0. DRB runs the unmodified upstream image
+`robotastic/trunk-recorder:5.2.1` (digest pinned in `docker-compose.yml`) as a
+separate program. It talks to DRB only through files, a script argument list
+and a local UDP socket. That makes it mere aggregation, the same position we
+already hold for OP25.
+
+Anyone we distribute a node image or device to must still be able to get the
+corresponding source. Upstream source for this exact version is at
+<https://github.com/TrunkRecorder/trunk-recorder/tree/v5.2.1>. If we ever ship
+the TR image ourselves (mirrored to our registry, preinstalled on a sold
+device), we must also offer that source directly, in writing, for three years,
+or ship it alongside. Pointing to upstream alone is not enough at that point.
+Any patch to TR itself makes DRB's copy a modified version, which must then be
+published under GPL-3.0.
diff --git a/trunk-recorder/drb-upload.sh b/trunk-recorder/drb-upload.sh
new file mode 100644
index 0000000..b7ede89
--- /dev/null
+++ b/trunk-recorder/drb-upload.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+# Trunk Recorder uploadScript (node-26#45). TR runs this after every call as
+#     drb-upload.sh <call.wav> <call.json> <call.m4a>
+# (run_upload_script_argv, call_concluder.cc v5.2.1; the m4a only exists with
+# compressWav, which DRB leaves off). TR deletes the wav/json as soon as this
+# exits (audioArchive/callLog false), so it copies them into the edge-node's
+# inbox first. Order matters: the WAV lands first and the JSON last, so the
+# JSON's presence tells the edge-node the WAV is complete. Exit non-zero = TR
+# marks the call failed.
+set -u
+WAV="${1:?wav path}"
+JSON="${2:?json path}"
+INBOX="${DRB_TR_INBOX:-/recordings/tr-inbox}"
+TMP="$INBOX/.incoming"
+
+[ -f "$WAV" ] && [ -f "$JSON" ] || { echo "drb-upload: missing $WAV or $JSON" >&2; exit 1; }
+mkdir -p "$TMP" || exit 1
+
+stem="$(basename "$JSON" .json)"
+# Hard link when on the same filesystem (no copy, TR's unlink leaves ours);
+# copy otherwise.
+put() { ln -f "$1" "$2" 2>/dev/null || cp -f "$1" "$2"; }
+
+put "$WAV" "$TMP/$stem.wav" || exit 1
+put "$JSON" "$TMP/$stem.json" || exit 1
+mv -f "$TMP/$stem.wav" "$INBOX/$stem.wav" || exit 1
+mv -f "$TMP/$stem.json" "$INBOX/$stem.json" || exit 1
+exit 0
diff --git a/trunk-recorder/run.sh b/trunk-recorder/run.sh
new file mode 100644
index 0000000..d04577e
--- /dev/null
+++ b/trunk-recorder/run.sh
@@ -0,0 +1,87 @@
+#!/bin/sh
+# Supervisor for Trunk Recorder inside its container (node-26#45).
+#
+# The edge-node writes /app/config.json from the C2 system config but has no
+# Docker access, so it cannot restart this container. This loop does it:
+#   - waits for config.json, then runs trunk-recorder on it
+#   - restarts it when config.json changes or /app/restart-request appears
+#   - keeps it stopped while /app/stop-request exists (dashboard Stop)
+#   - restarts it after a crash, backing off 5 s -> 60 s (`restarts` counts
+#     crashes only, not config restarts)
+#   - writes /app/drb-status.json every few seconds for the edge-node's health
+#     check (state, pid, started_at, restarts, last_exit, epoch)
+set -u
+APP="${DRB_TR_APP:-/app}"
+CFG="$APP/config.json"
+STATUS="$APP/drb-status.json"
+RESTART="$APP/restart-request"
+STOP="$APP/stop-request"
+REC="${DRB_RECORDINGS:-/recordings}"
+mkdir -p "$APP/logs" "$REC/tr-capture" "$REC/tr-inbox"
+
+pid=""
+started=0
+restarts=0
+last_exit=null
+backoff=5
+cfgsum=""
+
+write_status() {
+  printf '{"state":"%s","pid":%s,"started_at":%s,"restarts":%s,"last_exit":%s,"epoch":%s}\n' \
+    "$1" "${pid:-null}" "$started" "$restarts" "$last_exit" "$(date +%s)" > "$STATUS.tmp" \
+    && mv -f "$STATUS.tmp" "$STATUS"
+}
+
+sum() { md5sum "$CFG" 2>/dev/null | cut -d' ' -f1; }
+
+stop_tr() {
+  if [ -n "$pid" ] && kill -0 "$pid" 2>/dev/null; then
+    kill -TERM "$pid"
+    i=0
+    while kill -0 "$pid" 2>/dev/null && [ "$i" -lt 30 ]; do sleep 0.5; i=$((i + 1)); done
+    kill -KILL "$pid" 2>/dev/null
+    wait "$pid" 2>/dev/null
+  fi
+  pid=""
+}
+
+trap 'stop_tr; write_status stopped; exit 0' TERM INT
+
+nap() { sleep "$1" & wait $!; }
+
+while :; do
+  if [ -f "$STOP" ]; then
+    [ -n "$pid" ] && { echo "drb: stop requested"; stop_tr; }
+    write_status stopped; nap 2; continue
+  fi
+  if [ ! -f "$CFG" ]; then
+    write_status waiting_for_config; nap 5; continue
+  fi
+  if [ -z "$pid" ]; then
+    rm -f "$RESTART"
+    cfgsum="$(sum)"
+    echo "drb: starting trunk-recorder"
+    trunk-recorder --config="$CFG" &
+    pid=$!
+    started="$(date +%s)"
+  fi
+  write_status running
+  nap 5
+  if ! kill -0 "$pid" 2>/dev/null; then
+    wait "$pid" 2>/dev/null
+    last_exit=$?
+    pid=""
+    restarts=$((restarts + 1))
+    # A run that lasted a while resets the backoff.
+    [ $(( $(date +%s) - started )) -gt 120 ] && backoff=5
+    echo "drb: trunk-recorder exited ($last_exit); restarting in ${backoff}s"
+    write_status crashed
+    nap "$backoff"
+    backoff=$((backoff * 2)); [ "$backoff" -gt 60 ] && backoff=60
+    continue
+  fi
+  if [ -f "$RESTART" ] || [ "$(sum)" != "$cfgsum" ]; then
+    echo "drb: config changed or restart requested — restarting trunk-recorder"
+    stop_tr
+  fi
+done