从零编写第一个 TypeScript MCP Server：构建自己的本地天气与系统监控工具

mkdir my-mcp-server && cd my-mcp-server
npm init -y
npm install @modelcontextprotocol/sdk zod
npm install -D typescript @types/node tsx
npx tsc --init

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import { z } from "zod";

const server = new Server(
  { name: "system-toolset", version: "1.0.0" },
  { capabilities: { tools: {} } }
);

// 定义工具列表
server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "get_system_stats",
        description: "获取当前宿主机的内存使用率与系统运行时间",
        inputSchema: {
          type: "object",
          properties: {},
        },
      },
    ],
  };
});

// 处理工具调用
server.setRequestHandler(CallToolRequestSchema, async (request) => {
  if (request.params.name === "get_system_stats") {
    const os = await import("node:os");
    const totalMem = (os.totalmem() / 1024 / 1024 / 1024).toFixed(2);
    const freeMem = (os.freemem() / 1024 / 1024 / 1024).toFixed(2);
    return {
      content: [
        {
          type: "text",
          text: `操作系统: ${os.type()} ${os.release()}\n总内存: ${totalMem} GB\n可用内存: ${freeMem} GB\n运行时间: ${Math.floor(os.uptime() / 60)} 分钟`,
        },
      ],
    };
  }
  throw new Error(`未知工具: ${request.params.name}`);
});

// 使用 stdio 传输
async function run() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
  console.error("System Toolset MCP Server running on stdio");
}

run().catch((err) => {
  console.error("运行失败:", err);
  process.exit(1);
});

{
  "mcpServers": {
    "system-stats": {
      "command": "npx",
      "args": ["-y", "tsx", "c:/doc/code/my-mcp-server/src/index.ts"]
    }
  }
}