MCP Server & Client Python Example Using fastMCP Framework

README.md

MCP Server & Client Python Example Using fastMCP Framework

In this example, we will be creating an example of a MCP Server & Client Python Example Using fastMCP Framework

fastMCP is a popular Python framework for building MCP servers and clients. It abstracts protocol details, allowing focus on logic via decorators like @tool and @resource. Below are step-by-step examples with full, working code.

MCP Server in Python Using fastMCP

This example creates a simple MCP server with tools for basic math operations and a resource for version info.

1. Install fastMCP: Run pip install fastmcp (or uv pip install fastmcp for better dependency management).
2. Create the Server File: Save as mcp_server.py. (see file)
3. Run the Server: Execute python mcp_server.py. The server will be available at http://127.0.0.1:8000/mcp.
4. Test: Clients can now discover tools (e.g., add, multiply) and resources (e.g., config://version).

MCP Server in Python Using fastMCP

This example creates a client that connects to the above server, lists tools, and calls one.

1. Create the Client File: Save as mcp_client.py. (see file)
2. Run the Client: Ensure the server is running, then execute python mcp_client.py. Output will show tools, the addition result (8), and the version.

mcp_client.py

# Filename: mcp_client.py
import asyncio
from fastmcp import Client

async def main():
    # Connect to the server over HTTP
    async with Client("http://127.0.0.1:8000/mcp") as client:
        # List available tools
        tools = await client.list_tools()
        print("Available Tools:", tools)
        
        # Call the 'add' tool
        add_result = await client.call_tool("add", {"a": 5, "b": 3})
        print("Add Result:", add_result.content[0].text)
        
        # Read a resource
        version = await client.read_resource("config://version")
        print("Server Version:", version.content)

# Run the async main function
asyncio.run(main())

mcp_server.py

# Filename: mcp_server.py
from fastmcp import FastMCP

# Initialize the MCP server
mcp = FastMCP(name="Math MCP Server", description="A server for basic math operations")

# Define a tool for addition
@mcp.tool
def add(a: int, b: int) -> int:
    """Add two integers and return the result."""
    return a + b

# Define a tool for multiplication
@mcp.tool
def multiply(a: float, b: float) -> float:
    """Multiply two floats and return the result."""
    return a * b

# Define a static resource for server version
@mcp.resource("config://version")
def get_version():
    """Return the server version."""
    return "1.0.0"

if __name__ == "__main__":
    # Run the server over HTTP for remote access
    mcp.run(transport="http", host="127.0.0.1", port=8000, path="/mcp")