Python 使用 FastAPI 挂载多个 MCP 服务

Streamable HTTP 传输

注意：在生产部署中，Streamable HTTP 传输将取代 SSE 传输。

from mcp.server.fastmcp import FastMCP

# 有状态服务器（保持会话状态）
mcp = FastMCP("StatefulServer")

# 无状态服务器（无会话持久性）
mcp = FastMCP("StatelessServer", stateless_http=True)

# 无状态服务器（无会话持久性，无支持客户端的 sse 流）
mcp = FastMCP("StatelessServer", stateless_http=True, json_response=True)

# 使用 streamable_http 运行服务器
mcp.run(transport="streamable-http")

可以在 FastAPI 应用程序中挂载多个 MCP 服务：

# echo.py
from mcp.server.fastmcp import FastMCP

mcp = FastMCP(name="EchoServer", stateless_http=True)


@mcp.tool()
def echo(message: str) -> str:
    """A simple echo tool"""
    return f"Echo: {message}"

# math.py
from mcp.server.fastmcp import FastMCP

mcp = FastMCP(name="MathServer", stateless_http=True)


@mcp.tool()
def add_two(n: int) -> int:
    """Tool to add two to the input"""
    return n + 2

# main.py
import contextlib
from fastapi import FastAPI
from mcp.echo import echo
from mcp.math import math


# Create a combined lifespan to manage both session managers
@contextlib.asynccontextmanager
async def lifespan(app: FastAPI):
    async with contextlib.AsyncExitStack() as stack:
        await stack.enter_async_context(echo.mcp.session_manager.run())
        await stack.enter_async_context(math.mcp.session_manager.run())
        yield


app = FastAPI(lifespan=lifespan)
app.mount("/echo", echo.mcp.streamable_http_app())
app.mount("/math", math.mcp.streamable_http_app())

// 运行
import uvicorn
uvicorn.run(app)