MaleekNoob/custom_mcp_servers

FastMCP Server with Gmail Tool

This project demonstrates a simple FastMCP server with two available tools: a greet function for basic greetings and a send_email function that leverages the Google Gmail API to send emails.

Project Description

The server.py script sets up a Microservice Communication Protocol (MCP) server using the FastMCP framework. It exposes two remote procedure call (RPC) tools:

• greet(name: str): A simple tool that returns a greeting string.
• send_email(to_email: str, subject: str, body: str): A more advanced tool that connects to the Google Gmail API to send an email to a specified recipient. It handles the OAuth2 authentication flow for you, requiring a one-time setup.

Prerequisites

Before you can run the server and use the send_email tool, you must complete the following steps to set up the Google Gmail API:

1. Google Cloud Project
   Go to the Google Cloud Console and create a new project.

2. Enable the Gmail API
   In your new project, navigate to APIs & Services → Library, then search for and enable the Gmail API.

3. Create OAuth 2.0 Credentials

   • Go to APIs & Services → Credentials
   • Click + CREATE CREDENTIALS and select OAuth client ID
   • Choose Desktop app as the application type
   • Name your client and click Create

4. Download credentials.json
   A pop-up will display your client ID and secret. Click the DOWNLOAD JSON button and save the file as credentials.json in the same directory as your server.py script.

Installation

You can install the required libraries using either uv (recommended) or pip.

Using uv (Recommended)

First, make sure uv is installed on your system. Then run:

uv add fastmcp
uv add google-api-python-client google-auth-httplib2 google-auth-oauthlib

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Using pip

Alternatively, install the packages with pip:

pip install mcp
pip install fastmcp google-api-python-client google-auth-httplib2 google-auth-oauthlib

Usage

Step 1: Initial Authentication

Before running the server with fastmcp dev, perform a one-time authentication to generate the token.json file. This file securely stores your credentials.

Run the script:

python server.py

This will open a browser window and guide you through Google's authentication process. After a successful login, token.json will be created in your directory.

Step 2: Running the Server

Once you have the token.json file, you can start the FastMCP development server:

fastmcp dev server.py

You should see a message indicating that the server is running and the tools are registered.

Step 3: Using a Client

You can interact with the server's tools by using a client script.

Example:

# client.py

from fastmcp import connect

async def main():
    conn = await connect("http://localhost:8000")

    # Call greet tool
    greeting = await conn.call("greet", {"name": "Alice"})
    print("Greet response:", greeting)

    # Call send_email tool
    result = await conn.call("send_email", {
        "to_email": "example@example.com",
        "subject": "Test Email",
        "body": "Hello from FastMCP!"
    })
    print("Send email response:", result)

import asyncio
asyncio.run(main())