Vercel MCP Python Server

A Model Context Protocol (MCP) server built with Python and FastMCP, designed to run on Vercel's serverless platform.

Project Structure

vercel-mcp-python/ ├── api/ │ └── index.py # Main Vercel function ├── src/ │ └── mcp_server.py # Your MCP server logic ├── client-app/ # Interactive MCP client │ ├── mcp_client.py # Rich client application │ ├── requirements.txt # Client dependencies │ ├── setup.py # Setup script │ ├── README.md # Client documentation │ └── run_client.bat # Windows launcher ├── requirements.txt # Server dependencies ├── vercel.json # Vercel configuration └── README.md

Features

This MCP server provides the following tools:

echo: Echo back a provided message
get_time: Get the current server time
add_numbers: Add two numbers together
get_weather_info: Get mock weather information for a location

And the following resources:

config://server: Server configuration information

Prerequisites

Before setting up the project, you'll need to install the Vercel CLI:

Installing Vercel CLI

For Git Bash on Windows:

Install Node.js (if not already installed):
- Download from nodejs.org
Install Vercel CLI globally:
npm install -g vercel
Verify installation:
vercel --version

If you encounter PATH issues:

# Find npm global directory npm config get prefix # Add to PATH (add this to your ~/.bashrc) export PATH=$PATH:$(npm bin -g) source ~/.bashrc

Alternative methods:

# Using npx (no global installation) npx vercel # Using yarn yarn global add vercel

Setup

Create and activate virtual environment (Recommended):
# Create virtual environment python -m venv venv # Activate virtual environment # On Windows PowerShell: .\venv\Scripts\Activate.ps1 # On Windows Git Bash: source venv/Scripts/activate # On macOS/Linux: source venv/bin/activate
Install dependencies:
pip install -r requirements.txt
Login to Vercel:
vercel login
Deploy to Vercel:
vercel --prod

Local Development

To test locally, you can use Vercel's development server:

vercel dev

Troubleshooting Windows Issues

Note: Local development with vercel dev may have issues on Windows due to runtime initialization errors. This is a known limitation and doesn't affect production deployment.

If you encounter issues with

Solution 1: Deploy directly (Recommended)

vercel --prod

Your server will be available at the provided Vercel URL and works perfectly in production.

Solution 2: Test locally with Python (in virtual environment)

# Activate virtual environment first .\venv\Scripts\Activate.ps1 # Windows PowerShell # or source venv/Scripts/activate # Windows Git Bash # Test MCP server functionality python -c " import sys, os sys.path.append('src') from mcp_server import mcp import json # Test echo tool request = { 'jsonrpc': '2.0', 'id': 1, 'method': 'tools/call', 'params': {'name': 'echo', 'arguments': {'message': 'Hello from venv!'}} } response = mcp.handle_request(request) print(json.dumps(response, indent=2)) "

Solution 3: Use the deployed version Your server will be available at your Vercel domain after deployment.

You can test it by:

Opening the URL in your browser
Using a tool like Postman or curl
Connecting with an MCP client

Solution 4: Run as Administrator (if needed)

Close your terminal
Right-click on Git Bash/PowerShell and select "Run as administrator"
Navigate back to your project: cd /d/repos/vercel-mcp-python
Try vercel dev again

API Endpoints

GET /: Returns server information and status
POST /: Handles MCP protocol requests
OPTIONS /: Handles CORS preflight requests

Dependencies

fastmcp>=0.15.0: FastMCP framework for building MCP servers
uvicorn>=0.24.0: ASGI server for Python web applications
python-json-logger>=2.0.0: JSON logging for Python applications

Configuration

The server is configured through vercel.json with:

Python runtime using @vercel/python
30-second maximum execution time
CORS enabled for cross-origin requests
Automatic routing to the main handler

Usage

Once deployed, your MCP server will be available at your Vercel domain. You can connect to it using any MCP-compatible client.

Using the Included Client App

A rich, interactive client application is included in the client-app/ directory:

# Navigate to client directory cd client-app # Setup (first time only) python setup.py # Configure environment (optional) cp .env.example .env # Edit .env to customize server URL and settings # Run the client python mcp_client.py

The client provides:

🔌 Connection testing
🔧 Interactive tool calling
📚 Resource management
🧪 Automated testing of all tools
🎨 Beautiful console interface

See client-app/README.md for detailed usage instructions.

Additional Resources

Vercel MCP Documentation - Official Vercel documentation for Model Context Protocol
MCP Servers Repository - Explore available MCP servers
AI SDK Documentation - Use the AI SDK to initialize MCP clients