10 KiB
Add Signal Channel (v2)
Adds Signal messaging support to NanoClaw v2 using signal-sdk (a TypeScript
wrapper around signal-cli). Unlike Telegram/Discord, Signal has no bot API —
NanoClaw registers as a full Signal account on a dedicated phone number.
Two registration paths:
- New number (recommended): Register a dedicated SIM or VoIP number as a standalone Signal account. NanoClaw owns the number entirely.
- Linked device: Join an existing Signal account as a secondary device via QR code. Simpler, but NanoClaw shares your personal number.
Both paths are documented below. The new-number path is battle-tested.
Pre-flight
Check if src/channels/signal.ts exists and the import is uncommented in
src/channels/index.ts. If both are in place, skip to Registration.
Install
1. Check Java
Java 17+ is required. Check:
java -version
If missing:
- RHEL/CentOS/Fedora:
sudo dnf install -y java-17-openjdk - Debian/Ubuntu:
sudo apt-get install -y default-jre - macOS:
brew install --cask temurin@17
Java 17–25 all work. Java 25 (RHEL9 default) is confirmed working.
2. Install signal-cli
The signal-sdk npm package bundles signal-cli, but the bundled version is
often outdated. Install the latest standalone binary:
SIGNAL_CLI_VERSION=$(curl -fsSL https://api.github.com/repos/AsamK/signal-cli/releases/latest | python3 -c "import sys,json; print(json.load(sys.stdin)['tag_name'][1:])")
curl -fsSL "https://github.com/AsamK/signal-cli/releases/download/v${SIGNAL_CLI_VERSION}/signal-cli-${SIGNAL_CLI_VERSION}-Linux-native.tar.gz" \
| tar -xz -C ~/.local
ln -sf ~/.local/signal-cli ~/.local/bin/signal-cli
signal-cli --version
Note: The Linux native tarball extracts a single binary directly to
~/.local/signal-cli(not into a subdirectory). The symlink above handles this.
3. Install signal-sdk
npm install signal-sdk
4. Enable the adapter
Uncomment the Signal import in src/channels/index.ts:
import './signal.js';
5. Build
Always build with Node 22 (nvm):
source ~/.nvm/nvm.sh && nvm use 22 && npm run build
Path A: Register a new Signal number
Use this if you have a dedicated SIM or VoIP number for NanoClaw.
VoIP numbers: Signal requires SMS verification before voice. Some VoIP providers are blocked even for voice calls. If registration fails with an auth error, try a different provider or a physical SIM.
Step 1: Request SMS verification
Signal requires a CAPTCHA on first registration:
- Open
https://signalcaptchas.org/registration/generate.htmlin a browser - Solve the captcha
- Right-click the "Open Signal" button → Copy Link
- The link starts with
signalcaptcha://...
SIGNAL_CLI_CONFIG_PATH=/path/to/nanoclaw/data/signal \
signal-cli -u +YOURNUMBER register \
--captcha "PASTE_CAPTCHA_TOKEN_HERE"
The captcha token is everything after signalcaptcha:// in the copied link.
Step 2: Voice call fallback (VoIP numbers without SMS)
If your number cannot receive SMS, wait ~60 seconds after the SMS request then request a voice call:
SIGNAL_CLI_CONFIG_PATH=/path/to/nanoclaw/data/signal \
signal-cli -u +YOURNUMBER register --voice \
--captcha "SAME_CAPTCHA_TOKEN"
Signal will call your number and read a 6-digit code.
The captcha token from Step 1 is reusable for the voice retry — no need to solve a new one.
Step 3: Verify
SIGNAL_CLI_CONFIG_PATH=/path/to/nanoclaw/data/signal \
signal-cli -u +YOURNUMBER verify CODE
No output = success.
Step 4: Set profile name (optional)
⚠ signal-sdk holds an exclusive lock on
data/signal/while nanoclaw is running. Stop the service before running signal-cli commands, then restart.
systemctl --user stop nanoclaw
SIGNAL_CLI_CONFIG_PATH=/path/to/nanoclaw/data/signal \
signal-cli -u +YOURNUMBER updateProfile --name "YourBotName"
systemctl --user start nanoclaw
To set an avatar too:
signal-cli -u +YOURNUMBER updateProfile --name "YourBotName" --avatar /path/to/avatar.jpg
Path B: Link as secondary device
Use this to join an existing Signal account as a secondary device.
mkdir -p data/signal
export SIGNAL_CLI_CONFIG_PATH=$(pwd)/data/signal
npx signal-sdk link -n "NanoClaw" -a +YOURNUMBER
This prints a QR code. On your phone: Settings → Linked Devices → Link New Device. Scan the code within ~30 seconds.
Configure environment
Add to .env:
SIGNAL_PHONE_NUMBER=+YOURNUMBER
Wire to an agent
DMs
After the service starts, send any message to the Signal number from your
personal Signal app. The router auto-creates a messaging_groups row. Then:
sqlite3 data/v2.db \
"SELECT id, platform_id FROM messaging_groups WHERE channel_type='signal' ORDER BY created_at DESC LIMIT 5"
Pass the id and platform_id to /init-first-agent or wire manually.
Important: DM platform_id is UUID-based, not phone-based:
- DM:
signal:3de71d7f-ffa3-437e-b4db-097534bccd46(UUID of sender) - Group:
signal:UwaIz6bc09Olg1pBr/XeBuQf6z3fyCZoNj/Y3Tpe3hI=(base64 group ID)
Groups
Add the Signal number to a group from your phone. Send any message — the router
auto-creates the group's messaging_groups row. Wire it:
sqlite3 data/v2.db \
"SELECT id, platform_id FROM messaging_groups WHERE channel_type='signal' ORDER BY created_at DESC LIMIT 5"
Then insert the wiring (replace IDs):
NOW=$(date -u +"%Y-%m-%dT%H:%M:%S.000Z")
sqlite3 data/v2.db "
INSERT OR IGNORE INTO messaging_group_agents
(id, messaging_group_id, agent_group_id, session_mode, priority, created_at)
VALUES
('mga-'||hex(randomblob(8)), 'mg-GROUPID', 'ag-AGENTID', 'isolated', 0, '$NOW');
"
Use session_mode='isolated' for groups so each group has its own session.
Grant user access
Users who message via Signal need to be granted membership. Without this,
messages are silently dropped with not_member. After first contact:
NOW=$(date -u +"%Y-%m-%dT%H:%M:%S.000Z")
sqlite3 data/v2.db "
INSERT OR REPLACE INTO user_roles (user_id, role, agent_group_id, granted_by, granted_at)
VALUES ('signal:UUID', 'owner', NULL, 'system', '$NOW');
INSERT OR IGNORE INTO agent_group_members (user_id, agent_group_id, added_by, added_at)
VALUES ('signal:UUID', 'ag-AGENTID', 'system', '$NOW');
"
Find the UUID from messaging_groups.platform_id or the users table.
Voice Transcription (optional)
Inbound voice messages are automatically transcribed using a local whisper binary. The feature degrades gracefully — if whisper or ffmpeg is missing, voice messages are still delivered as attachments with no transcript.
See /add-voice-transcription-free-whisper for full setup instructions
(ffmpeg, whisper backends, model download, environment variables, troubleshooting).
Channel Info
- type:
signal - terminology: "Chats" (1:1) and "groups" (multi-member). No threads.
- supports-threads: no
- inbound: text, reactions (forwarded to agent with emoji + targetTimestamp), images, files, voice (transcribed via whisper-cli if installed)
- outbound: text, reactions (sendReaction), file attachments
- platform-id-format:
- DM:
signal:{UUID}— sender's Signal UUID, not their phone number - Group:
signal:{base64GroupId}
- DM:
- how-to-find-id: Send a message to the bot, then query
messaging_groupsas shown above. - config-lock: signal-sdk holds an exclusive lock on
data/signal/while nanoclaw is running. Stop the service before running anysignal-clicommands. - attachment storage: signal-sdk launches signal-cli without a
--configflag, so signal-cli stores attachments at the XDG default (~/.local/share/signal-cli/attachments/), not underdata/signal/. The adapter checks both locations. Verify with:ps aux | grep signal-cli— if there is no-cargument, XDG default is in use.
Troubleshooting
Config file is in use by another instance — nanoclaw is running and
signal-sdk has the lock. Stop the service, run the command, restart.
Messages dropped with not_member — the Signal user hasn't been granted
membership. See "Grant user access" above. This affects every new Signal user,
including the owner's Signal identity (which is separate from their Telegram
identity even if it's the same person).
Captcha required — Signal requires captcha for new registrations. Go to
https://signalcaptchas.org/registration/generate.html, solve it, right-click
"Open Signal", copy the link, extract the token after signalcaptcha://.
Invalid verification method: Before requesting voice verification… —
You must request SMS first, wait ~60 seconds, then request voice. Both can use
the same captcha token.
The provided model identifier is invalid (Bedrock) — unrelated to Signal;
this is a LiteLLM model ID issue.
Group replies going to DM instead of group — modern Signal groups use
GroupV2. The adapter must extract the group ID from
envelope?.dataMessage?.groupV2?.id (not just groupInfo?.groupId, which is
GroupV1/legacy). Check src/channels/signal.ts and confirm the groupId
extraction falls through to groupV2.id.
Voice messages / attachments silently skipped, no transcript — signal-sdk
launches signal-cli without a --config flag, so attachments land at the XDG
default (~/.local/share/signal-cli/attachments/) rather than under
data/signal/. Confirm with ps aux | grep signal-cli — if there is no -c
argument in the process line, the XDG default is in use. The adapter falls back
to that location automatically. If you still see no "Signal attachment saved"
log lines, add a debug log around the if (!storedPath) continue guard in
src/channels/signal.ts to inspect att.storedFilename and att.id.
Java not found — install Java 17+ (see Install step 1).
QR code expired (Path B) — QR codes expire in ~30 seconds. Re-run the link command to generate a new one.
signal-cli binary location — The native Linux tarball extracts directly to
~/.local/signal-cli (a single file, not a directory). The system aws or
other tools named signal-cli won't be in PATH by default; check
~/.local/bin/signal-cli.