whatsapp_server.py•3.49 kB
# whatsapp_server.py
import os
from typing import Annotated
from pydantic import BeforeValidator, Field
from pydantic_settings import BaseSettings, SettingsConfigDict
from twilio.rest import Client as TwilioClient
from twilio.base.exceptions import TwilioRestException
from fastmcp import FastMCP
# --- Configuration Loading ---
class Settings(BaseSettings):
# Load variables from .env file, prefixed with TWILIO_
model_config = SettingsConfigDict(env_prefix="TWILIO_", env_file=".env")
account_sid: str = Field(..., description="Twilio Account SID")
auth_token: str = Field(..., description="Twilio Auth Token")
# Ensure the number starts with '+' using a validator
whatsapp_number: Annotated[
str, BeforeValidator(lambda v: f"+{v}" if not str(v).startswith('+') else str(v))
] = Field(..., description="Your Twilio WhatsApp number (e.g., +14155238886)")
# Load settings from environment variables / .env file
try:
settings = Settings() # type: ignore
except Exception as e:
print(f"Error loading settings: {e}")
print("Please ensure you have a .env file with TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, and TWILIO_WHATSAPP_NUMBER set.")
exit(1)
# --- FastMCP Server Setup ---
mcp = FastMCP(
"WhatsApp Messenger",
instructions="Use the send_whatsapp tool to send messages.",
# Add dependencies for `fastmcp install`
dependencies=["twilio", "python-dotenv", "pydantic-settings"]
)
# --- Twilio Client Initialization ---
# Initialize the Twilio client using loaded settings
twilio_client = TwilioClient(settings.account_sid, settings.auth_token)
# --- MCP Tool Definition ---
@mcp.tool()
def send_whatsapp(
to_number: Annotated[
str,
Field(description="Recipient's WhatsApp number in E.164 format (e.g., +15551234567)")
],
message: Annotated[str, Field(description="The message content to send")]
) -> str:
"""
Sends a WhatsApp message to the specified recipient number using Twilio.
The recipient number MUST be in E.164 format, including the 'whatsapp:' prefix
(e.g., 'whatsapp:+15551234567').
"""
# Ensure numbers are in the correct Twilio format (whatsapp:+E.164)
formatted_to = to_number if to_number.startswith('whatsapp:') else f"whatsapp:{to_number}"
formatted_from = settings.whatsapp_number if settings.whatsapp_number.startswith('whatsapp:') else f"whatsapp:{settings.whatsapp_number}"
try:
message_instance = twilio_client.messages.create(
from_=formatted_from,
body=message,
to=formatted_to
)
confirmation = f"WhatsApp message sent successfully to {to_number}. SID: {message_instance.sid}"
print(confirmation) # Also print to server console for visibility
return confirmation
except TwilioRestException as e:
error_message = f"Failed to send WhatsApp message to {to_number}: {e}"
print(f"ERROR: {error_message}") # Log error to server console
# Return the error message to the LLM/client
return error_message
except Exception as e:
# Catch other potential errors
error_message = f"An unexpected error occurred: {e}"
print(f"ERROR: {error_message}")
return error_message
# --- Run the Server ---
if __name__ == "__main__":
print(f"Starting WhatsApp MCP Server...")
print(f"Using Twilio Number: {settings.whatsapp_number}")
mcp.run() # Runs with stdio transport by default