OpenClaw Signal Setup: Connect Your AI Agent to Signal | MrDelegate

Step 1: Install Java 17

Signal CLI requires Java. On Ubuntu or Debian:

sudo apt update
sudo apt install -y openjdk-17-jre-headless
java --version

You should see output like openjdk 17.x.x. If you see Java 11 or older, install the newer version explicitly and set it as the default with sudo update-alternatives --config java.

Step 2: Download and Install Signal CLI

Download the latest Signal CLI release from the official GitHub repository. As of early 2026, the current version is 0.13.x:

cd /opt
sudo wget https://github.com/AsamK/signal-cli/releases/download/v0.13.3/signal-cli-0.13.3-Linux.tar.gz
sudo tar xf signal-cli-0.13.3-Linux.tar.gz
sudo ln -sf /opt/signal-cli-0.13.3/bin/signal-cli /usr/local/bin/signal-cli

Verify the install:

signal-cli --version

Step 3: Register a Phone Number

Your AI agent needs a dedicated phone number. Do not use your personal number — if something goes wrong, you could lose Signal access on your personal device. Use a secondary SIM, a Google Voice number, or a VoIP service like Twilio or MySudo that supports SMS verification.

Register the number with Signal:

signal-cli -u +15551234567 register

Signal will send an SMS to that number with a 6-digit verification code. Once you receive it:

signal-cli -u +15551234567 verify 123456

If SMS does not arrive within 60 seconds, request a voice call instead:

signal-cli -u +15551234567 register --voice

After successful verification, Signal CLI stores keys in ~/.local/share/signal-cli/. Back up this directory immediately. Losing these keys means losing access to the number on Signal.

Step 4: Run Signal CLI as a Daemon

OpenClaw communicates with Signal CLI through a Unix socket or JSON-RPC over TCP. Start Signal CLI in daemon mode:

signal-cli -u +15551234567 daemon --socket /tmp/signal-cli.sock

sudo tee /etc/systemd/system/signal-cli.service << EOF
[Unit]
Description=Signal CLI Daemon
After=network.target

[Service]
Type=simple
User=root
ExecStart=/usr/local/bin/signal-cli -u +15551234567 daemon --socket /tmp/signal-cli.sock
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl daemon-reload
sudo systemctl enable signal-cli
sudo systemctl start signal-cli

Step 5: Configure OpenClaw for Signal

openclaw configure --section signal

• Signal phone number: The number you registered above (e.g., +15551234567)
• Socket path: /tmp/signal-cli.sock (or the TCP port if you used --tcp)
• Authorized contacts: Your personal Signal number — only messages from these numbers are processed
• Group support: Enable if you want the agent to participate in Signal groups

After saving, restart the gateway:

openclaw gateway restart

Step 6: Send a Test Message

Open Signal on your phone and send a message to your agent's number. If everything is configured correctly, your OpenClaw agent responds within a few seconds. The response comes through Signal CLI and appears as a normal Signal message — encrypted end-to-end, just like any other Signal conversation.

If there is no response, check the logs:

openclaw gateway logs --tail 50

Common issues at this stage: the socket path is wrong, Signal CLI is not running, or the authorized contacts list does not include your number.

Real Use Cases for Signal + OpenClaw

Morning briefs: Schedule a daily summary to arrive at 7 AM — calendar events, urgent emails, weather, and any overnight alerts. Because it comes through Signal, it is fully encrypted and stays on your device, not in a cloud inbox.

Financial alerts: If you track expenses or run a business, configure your agent to send weekly spending summaries, invoice overdue alerts, or budget warnings via Signal. Sensitive financial data stays encrypted in transit.

Two-way commands: Send a message to your agent like "remind me about the Johnson proposal at 3pm" or "what's on my calendar tomorrow" and get an instant encrypted response. The same way you would use Telegram for agent commands, but with end-to-end encryption throughout.

Alert routing: Configure monitoring tools (uptime checkers, CI/CD pipelines, server alerts) to route through your OpenClaw agent, which then forwards critical alerts to your Signal number. You get paged via the most secure channel available.

Client communications: If you work with clients who use Signal, you can route specific client queries through an OpenClaw agent that handles first-line responses, schedules follow-ups, and logs the conversation.

Permissions and Security Considerations

Because Signal CLI stores cryptographic keys on your server, the security of your server matters. If someone gains access to your server's filesystem, they can read your Signal messages. Use standard server hardening:

• SSH key authentication only, password authentication disabled
• Firewall blocking all ports except 22, 80, 443
• Regular security updates: sudo apt-get update && sudo apt-get upgrade
• The Signal CLI data directory permissions set to 700

On the OpenClaw side, set up an authorized contacts list. Without this, anyone who discovers your agent's number could send it commands. The authorizedContacts setting in the Signal plugin configuration accepts an array of phone numbers in E.164 format (+1XXXXXXXXXX). Any message from a number not on this list is silently dropped.

Also consider: if your server is compromised after a prolonged period, an attacker could read message history stored by Signal CLI. Signal's disappearing messages feature can limit this exposure — configure a message lifetime via openclaw configure --section signal to auto-delete messages after 24 hours or 7 days.

Common Errors and How to Fix Them

Error: "Failed to connect to socket"
Signal CLI is not running or crashed. Check: systemctl status signal-cli. If failed, check journalctl -u signal-cli -n 50 for the error. Most common cause: stale socket file. Delete /tmp/signal-cli.sock and restart.

Error: "Unauthorized sender"
The message came from a number not in your authorized contacts list. Open openclaw configure --section signal and add the number to authorizedContacts.

Error: "Rate limited"
Signal rate-limits new registrations aggressively. If you registered a fresh number, wait 24 hours before heavy use. This clears automatically.

Error: "Registration required"
Your Signal CLI keys expired or were invalidated. Re-register the number: signal-cli -u +15551234567 register. Note this will invalidate the number on other devices too.

Messages appear but no response:
Check the authorized contacts list first. Then verify the gateway is running: openclaw gateway status. If both look fine, check whether your AI provider API key is valid and has remaining credits.

Signal vs Telegram: Which Should You Use?

For most OpenClaw users, Telegram is the right starting point. Setup takes 5 minutes, the API is stable and well-documented, and Telegram works well for all the typical agent tasks — morning briefs, commands, alerts, reminders.

Signal makes sense when:

• You are passing sensitive personal or financial data through your agent
• You work in a regulated industry (healthcare, legal, finance) where data handling matters
• You want end-to-end encryption verified by open-source code, not just a company's privacy policy
• Your team or clients already use Signal and you want to meet them there

There is no reason you cannot run both channels simultaneously. OpenClaw supports multiple active channels — configure Signal for sensitive communications and Telegram for general use, and your agent handles both from the same workspace.

How Teams Use Signal in Practice

Teams that already trust Signal for internal communication often prefer it for AI alerts as well. Operations staff can receive private deployment notices, incident summaries, and approval requests in a small Signal group instead of a noisy general chat. The OpenClaw agent becomes a secure dispatch layer rather than just a chatbot.

Client-facing firms can also create high-trust service channels where the agent handles routine questions and routes sensitive requests to humans. This is especially useful for founders, agencies, and professional services teams who need fast response times without pushing private updates through less secure messaging tools.

Maintenance Checklist After Setup

After installation, test the integration monthly. Verify Signal CLI is still running, confirm the socket path works after a reboot, and send a live message from an authorized number. Keep a backup of the Signal CLI keys directory in a secure location. If you lose that directory, recovery becomes much harder than most people expect.

Also document the phone number, recovery steps, and systemd service details so someone on your team can restore the integration without guessing. Messaging channels tend to be forgotten until a day when they are urgently needed. A short maintenance checklist prevents that kind of failure.

When Signal Is the Right Choice

Signal is not the best default for every user, but it is the right choice when the privacy of the channel matters as much as the convenience of the agent. Founders handling sensitive company updates, operators sharing financial alerts, and professionals discussing client matters often prefer an encrypted lane they already trust. In those cases, the extra setup work pays for itself quickly.