Fork Notice: This is a security-hardened fork of rymurr/signal-mcp with additional features inspired by signal-cli-rest-api.

An MCP integration for signal-cli that allows AI agents to send and receive Signal messages.

This fork includes the following security improvements:

1. Log level changed from DEBUG to INFO - Prevents sensitive message content and phone numbers from being logged
2. Phone number validation - E.164 format validation prevents malformed inputs
3. Timeout bounds - Maximum timeout capped at 300 seconds to prevent resource exhaustion
4. MIT License added - Clear licensing terms

• send_message_to_user - Send a direct message to a Signal user
• send_message_to_group - Send a message to a Signal group
• receive_message - Wait for and receive messages with timeout support (max 300s)
• send_message_with_attachment - Send messages with file attachments

• link_device - Generate QR code link URI to connect as secondary device to existing Signal account
• check_signal_registration - Check if a phone number is registered with Signal

• list_contacts - List all contacts known to signal-cli
• list_groups - List all Signal groups you are a member of

• send_reaction - React to messages with emoji
• send_read_receipt - Mark messages as read

This project requires signal-cli to be installed and configured on your system.

1. Download signal-cli from the official releases

2. Extract and add to PATH (e.g., C:\tools\signal-cli\bin)

You don't need a new phone number! Signal-cli can link as a secondary device to your existing account (like Signal Desktop):

1. Run the link command:

   signal-cli link --name "Claude MCP"

2. This outputs a sgnl://linkdevice?uuid=... URI

3. Convert to QR code (using any QR generator or qrencode on Linux)

4. Open Signal on your phone → Settings → Linked Devices → + button → Scan QR code

5. The MCP server can now send/receive messages on your behalf

cd signal-mcp
uv sync

Run the MCP server:

uv run python -m signal_mcp.main --user-id +YOUR_PHONE_NUMBER --transport stdio

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "signal": {
      "command": "uv",
      "args": ["run", "python", "-m", "signal_mcp.main", "--user-id", "+YOUR_PHONE_NUMBER", "--transport", "stdio"],
      "cwd": "C:/path/to/signal-mcp"
    }
  }
}

# Install dependencies
uv sync

# Run linting
uv run ruff check .

# Run type checking
uv run mypy .

MIT License - see LICENSE file.

• Original project by Ryan Murray (@rymurr)
• Additional features inspired by signal-cli-rest-api by @bbernhard