MCP实战-本地MCP Server + Client实战

概述

本文开发一个MCP的Client和Server。然后通过本地模式来运行，并获取到server的结果。

MCP Server开发

import anyio
import click
import mcp.types as types
from mcp.server.lowlevel import Server
from pydantic import FileUrl

SAMPLE_RESOURCES = {
    "greeting": "Hello! This is a sample text resource.",
    "help": "This server provides a few sample text resources for testing.",
    "about": "This is the simple-resource MCP server implementation.",
}

@click.command()
@click.option("--port", default=10005, help="Port to listen on for SSE")
@click.option(
    "--transport",
    type=click.Choice(["stdio", "sse"]),
    default="stdio",
    help="Transport type",
)
def main(port: int, transport: str) -> int:
    app = Server("mcp-simple-resource")

    @app.list_resources()
    async def list_resources() -> list[types.Resource]:
        return [
            types.Resource(
                uri=FileUrl(f"file:///var/domcp/{name}.txt"),
                name=name,
                description=f"A sample text resource named {name}",
                mimeType="text/plain",
            )
            for name in SAMPLE_RESOURCES.keys()
        ]

    @app.read_resource()
    async def read_resource(uri: FileUrl) -> str | bytes:
        name = uri.path.replace(".txt", "").lstrip("/")

        if name not in SAMPLE_RESOURCES:
            raise ValueError(f"Unknown resource: {uri}")

        return SAMPLE_RESOURCES[name]

    if transport == "sse":
        from mcp.server.sse import SseServerTransport
        from starlette.applications import Starlette
        from starlette.routing import Mount, Route

        sse = SseServerTransport("/messages/")

        async def handle_sse(request):
            async with sse.connect_sse(
                request.scope, request.receive, request._send
            ) as streams:
                await app.run(
                    streams[0], streams[1], app.create_initialization_options()
                )

        starlette_app = Starlette(
            debug=True,
            routes=[
                Route("/sse", endpoint=handle_sse),
                Mount("/messages/", app=sse.handle_post_message),
            ],
        )

        import uvicorn

        uvicorn.run(starlette_app, host="0.0.0.0", port=port)
    else:
        from mcp.server.stdio import stdio_server

        async def arun():
            async with stdio_server() as streams:
                await app.run(
                    streams[0], streams[1], app.create_initialization_options()
                )

        anyio.run(arun)

    return 0

if __name__ == "__main__":
    main()

MCP Client开发

这里使用

import asyncio
from mcp.types import AnyUrl
from mcp.client.session import ClientSession
from mcp.client.stdio import StdioServerParameters, stdio_client


async def main():
    async with stdio_client(
        StdioServerParameters(command="python", args=["/root/domcp/server2.py"])
    ) as (read, write):
        async with ClientSession(read, write) as session:
            await session.initialize()

            # List available resources
            resources = await session.list_resources()
            print(resources)

            print("----------------------")
            # Get a specific resource
            resource = await session.read_resource(AnyUrl("file:///greeting.txt"))
            print(resource)

asyncio.run(main())

运行MCP Client

运行Client后输出如下内容：

(ailab) root@tra:~/domcp# python client2.py 
meta=None nextCursor=None resources=[Resource(uri=Url('file:///root/domcp/greeting.txt'), name='greeting', description='A sample text resource named greeting', mimeType='text/plain', size=None, annotations=None), Resource(uri=Url('file:///root/domcp/help.txt'), name='help', description='A sample text resource named help', mimeType='text/plain', size=None, annotations=None), Resource(uri=Url('file:///root/domcp/about.txt'), name='about', description='A sample text resource named about', mimeType='text/plain', size=None, annotations=None)]

----------------------
meta=None contents=[TextResourceContents(uri=Url('file:///greeting.txt'), mimeType='text/plain', text='Hello! This is a sample text resource.')]