Connect Signal Messenger

Set up Moltbot with Signal for private, encrypted AI conversations. Complete Signal integration guide.

Medium ⏱️ 15 min

Overview

Connect Moltbot to Signal for the most private AI conversations:

  • End-to-end encryption — Messages stay private
  • No metadata collection — Signal’s privacy-first approach
  • Group support — AI in Signal groups
  • Media handling — Process images and voice notes

Prerequisites

  • Moltbot installed on your machine
  • A phone number dedicated for the bot (can be a VoIP number)
  • Signal app installed on a phone for initial registration

Important: Phone Number Requirement

Signal requires a phone number for registration. Options:

  1. Dedicated SIM — Best for production use
  2. VoIP number — Google Voice, Twilio (some may be blocked)
  3. Dual SIM phone — Use secondary number

⚠️ Warning: Don’t use your personal Signal number. The bot will take over that account.

Step 1: Register Signal Account

Install signal-cli:

# macOS
brew install signal-cli

# Linux
wget https://github.com/AsamK/signal-cli/releases/latest/download/signal-cli-0.12.0.tar.gz
tar xf signal-cli-*.tar.gz
sudo mv signal-cli-*/bin/signal-cli /usr/local/bin/

Register your number:

signal-cli -u +1234567890 register

You’ll receive an SMS with a verification code. Complete verification:

signal-cli -u +1234567890 verify CODE

Option B: Using Moltbot’s Built-in Registration

moltbot channels add signal --register

Follow the prompts to enter your phone number and verification code.

If you used signal-cli:

moltbot channels add signal

Enter your phone number when prompted. Moltbot will use the existing signal-cli registration.

Step 3: Configure Safety Groups

Signal requires “safety numbers” verification for secure conversations. Configure trusted contacts:

# Trust a specific contact
moltbot config set signal.trustedNumbers "+1987654321,+1555123456"

Or trust all contacts (less secure):

moltbot config set signal.trustAllKeys true

Step 4: Start the Gateway

moltbot gateway

Test by sending a message to your bot’s Signal number from another phone.

Group Chat Setup

Join a Group

  1. Create a Signal group or use an existing one
  2. Add your bot’s phone number to the group
  3. The bot will automatically start receiving group messages

Configure Group Behavior

# Respond to all messages in groups
moltbot config set signal.groups.replyToAll true

# Or only respond when mentioned by name
moltbot config set signal.groups.replyToAll false
moltbot config set signal.botName "AI"  # Responds to "AI, what is..."

Configuration Options

Set Allowed Contacts

Restrict who can message the bot:

moltbot config set signal.allowList "+1234567890,+0987654321"

Disappearing Messages

Match the group’s disappearing message setting:

moltbot config set signal.respectDisappearing true

Read Receipts

# Send read receipts (shows when bot read the message)
moltbot config set signal.sendReadReceipts true

Handling Media

Voice Notes

Signal voice notes are automatically transcribed and processed:

moltbot config set signal.transcribeVoice true

Images

Enable image understanding:

moltbot config set signal.processImages true

The AI can describe and analyze images sent to it.

Running as a Service

For 24/7 availability, run as a system service:

systemd (Linux)

sudo nano /etc/systemd/system/moltbot-signal.service
[Unit]
Description=Moltbot Signal Gateway
After=network.target

[Service]
Type=simple
User=YOUR_USERNAME
ExecStart=/usr/bin/moltbot gateway
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target
sudo systemctl enable moltbot-signal
sudo systemctl start moltbot-signal

Troubleshooting

”Unregistered User” Error

Your Signal registration may have expired. Re-register:

signal-cli -u +YOUR_NUMBER register
signal-cli -u +YOUR_NUMBER verify CODE

“Untrusted Identity” Error

Signal detects a new device. Trust it:

signal-cli -u +YOUR_NUMBER trust -a CONTACT_NUMBER

Or configure Moltbot to auto-trust:

moltbot config set signal.trustAllKeys true

Messages Not Receiving

  1. Verify registration: signal-cli -u +NUMBER receive
  2. Check phone number format (include country code)
  3. Ensure gateway is running: moltbot status

Rate Limiting

Signal may rate-limit new accounts. If messages fail:

  • Wait 24 hours before heavy use
  • Start with fewer messages
  • Don’t spam or you’ll be banned

Security Best Practices

  1. Use a dedicated number — Don’t mix personal and bot accounts
  2. Enable safety number verification — For sensitive conversations
  3. Restrict allowed contacts — Don’t open to everyone
  4. Monitor for abuse — Check logs regularly
  5. Keep signal-cli updated — Security patches matter

Next Steps