MCP Python SDK

MCP Python SDK

The MCP Python SDK is the official reference implementation of the Model Context Protocol from Anthropic's modelcontextprotocol organization. It provides the full low-level API for building both MCP servers (expose tools, resources, prompts) and MCP clients (connect to any MCP server), with complete spec compliance and async support.

Key features

• Full MCP spec implementation: tools, resources, resource templates, prompts, sampling, roots
• Both server and client APIs in one package
• Stdio and SSE transport support
• Async-first using Python's asyncio + anyio
• Pydantic models for all protocol messages — fully typed
• MIT license — use in any project, commercial or open-source

Quick start (server)

pip install mcp

from mcp.server import Server
from mcp.server.stdio import stdio_server
from mcp.types import Tool, TextContent

app = Server("my-server")

@app.list_tools()
async def list_tools():
    return [Tool(name="echo", description="Echo a message", inputSchema={
        "type": "object",
        "properties": {"message": {"type": "string"}},
        "required": ["message"]
    })]

@app.call_tool()
async def call_tool(name: str, arguments: dict):
    if name == "echo":
        return [TextContent(type="text", text=arguments["message"])]

async def main():
    async with stdio_server() as (r, w):
        await app.run(r, w, app.create_initialization_options())

import asyncio; asyncio.run(main())

Install via ai-supply

npx ai-supply add mcp-python-sdk

Curated mirror of the open-source MCP Python SDK (MIT). Get it from the source.