WhatsApp MCP Assistant (Client-Server)

This project builds a client-server pipeline to send and schedule WhatsApp messages using natural language. The server interprets user intent with Mistral's LLM and uses Twilio to perform the actual WhatsApp messaging.

Files

• mcp_server.py: The main MCP server that uses Mistral for interpreting user input and calls Twilio to send messages.
• mcp_client.py: Simple CLI client for interacting with the server using free-form natural language.
• config.py: Stores API keys and constants including phone number config.

Server-Client Idea

The server parses your intent using Mistral's LLM and converts it into actionable instructions (like sending a message). The client is a CLI interface where you type prompts like "Send a message to Nir", and the backend handles the rest.

Twilio:

Twilio provides a programmable WhatsApp messaging API. It's used here to send messages or simulate scheduling via WhatsApp.

⚠️ WhatsApp 24-Hour Window Limitation (Twilio)

If you're using Twilio's WhatsApp API, note that freeform messages (i.e., regular text messages) are only allowed within a 24-hour window after the user last messaged your WhatsApp number.

If you attempt to send a message outside of that window, you'll see this error in your Twilio dashboard: "Failed to send freeform message because you are outside the allowed window. If you are using WhatsApp, please use a Message Template"

✅ To fix this:

• You must use a pre-approved Message Template for messages sent after the 24-hour window.
• You can create templates in your Twilio Console > Messaging > Templates.

💡 For local testing:

If you’re just testing this with your own number and it’s failing, make sure you’ve sent a message to the Twilio number from your own WhatsApp recently — that resets the 24-hour window.

MCP Idea:

The MCP Server wraps a function-calling capable LLM (Mistral) to dynamically route user intent to appropriate tools (send/schedule WhatsApp messages). The client allows CLI-based prompt entry.

How to Run

1. Install dependencies:

   pip install twilio requests fastapi
   

2. Update config.py with real values.

3. Run the server:

   python mcp_server.py
   

4. In another terminal, run the client:

   python mcp_client.py