Signal MCP

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

Features

• Send messages to Signal users
• Send messages to Signal groups
• Receive and parse incoming messages
• Async support with timeout handling
• Detailed logging

Prerequisites

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

Installing signal-cli

1. Install signal-cli: Follow the official installation instructions

2. Register your Signal account:

   signal-cli -u YOUR_PHONE_NUMBER register

3. Verify your account with the code received via SMS:

   signal-cli -u YOUR_PHONE_NUMBER verify CODE_RECEIVED

For more detailed setup instructions, see the signal-cli documentation.

Installation

pip install -e .
# or use uv for faster installation
uv pip install -e .

Usage

Run the MCP server:

./main.py --user-id YOUR_PHONE_NUMBER [--transport {sse|stdio}]

API

Tools Available

• 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

Development

This project uses:

• MCP for agent-API integration
• Modern Python async patterns
• Type annotations throughout