Sample MCP Python

🚀 Overview

Sample MCP Python is a modern, container-ready MCP (Model Context Protocol) server built with FastMCP and FastAPI. It provides simple arithmetic tools and is designed for easy extension and cloud deployment.

✨ Features

• FastMCP Server: Implements MCP protocol for agent communication.
• Arithmetic Tools: Includes add and subtract as MCP tools.
• Custom Middleware: Logging middleware for all MCP operations.
• FastAPI Exception Handling: Handles session and route errors gracefully.
• Docker Support: Ready for containerized deployment.
• Configurable Logging: Debug and info logs for all operations.

🗂️ Project Structure

sample-mcp-python/
├── server.py          # Main MCP server with tools and middleware
├── test_server.py     # (Empty) Placeholder for tests
├── Dockerfile         # Container build instructions
├── pyproject.toml     # Python project metadata and dependencies
├── uv.lock            # Dependency lock file
├── .gitignore         # Git ignore rules
├── .dockerignore      # Docker ignore rules

🛠️ Usage

Prerequisites

• Python 3.12+
• Docker (optional, for container deployment)

Local Development

1. Install dependencies:

   uv sync

2. Run the server:

   uv run server.py

Docker

1. Build the image:

   docker build -t sample-mcp-python .

2. Run the container:

   docker run -p 3000:3000 sample-mcp-python

🧩 MCP Tools

• add(a: int, b: int) -> int: Adds two numbers.
• subtract(a: int, b: int) -> int: Subtracts the second number from the first.

⚙️ Configuration

• Port: Set the PORT environment variable to change the server port (default: 3000).
• Logging: Controlled via fastmcp.settings.log_level and Python logging config.

📝 Extending

Add new MCP tools by decorating functions with @mcp.tool() in server.py.
Custom middleware can be added for logging, authentication, etc.

🧪 Testing

Tests are written in test_server.py using pytest and pytest-asyncio for async support.

Run tests

Then, run the tests:

uv run pytest

Example async test:

import pytest
from fastmcp import Client
from server import mcp

client = Client(mcp)

@pytest.mark.asyncio
async def test_add_tool():
    async with client:
        result = await client.call_tool("add", {"a": 3, "b": 5})
        assert result == 8

📦 Dependencies

• fastmcp==2.10.6
• fastapi>=0.116.1

MCP Inspector

To test with MCP inspector, run it with npx: npx @modelcontextprotocol/inspector

📄 License

MIT License (add your license file if needed)

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Made with ❤️ using FastMCP and Python.