MCP TypeScript SDK 初体验：挑战快速搭建一个 AI 应用！

npm install @modelcontextprotocol/sdk axios

import {
  McpServer,
  ResourceTemplate,
} from"@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from"@modelcontextprotocol/sdk/server/stdio.js";
import { z } from"zod";

const facts = [
"公理1: 生存是文明的第一需要.",
"公理2: 文明不断增长和扩张，但宇宙中的物质总量保持不变.",
].map((f) => f.toLowerCase());

const server = new McpServer({
  name: "mcp-cli-server",
  version: "1.0.0",
});

// 使用 Zod 定义工具的输入模式
server.tool(
"search_local_database",
  z.object({ query: z.string() }),
async ({ query }) => {
    console.log("Tool called with query:", query);
    const queryTerms = query.toLowerCase().split(/\s+/);
    const results = facts.filter((fact) =>
      queryTerms.some((term) => fact.includes(term))
    );
    return {
      content: [
        {
          type: "text",
          text: results.length === 0 ? "未找到相关公理" : results.join("\n"),
        },
      ],
    };
  }
);

// 定义资源
server.resource(
"current_time",
new ResourceTemplate("time://current", { list: undefined }),
async (uri) => ({
    contents: [{ uri: uri.href, text: newDate().toLocaleString() }],
  })
);

await server.connect(new StdioServerTransport());
console.log("Server is running...");

// src/client.js;
import { Client } from"@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from"@modelcontextprotocol/sdk/client/stdio.js";

exportasyncfunction createClient() {
const client = new Client({
    name: "Demo",
    version: "1.0.0",
  });

const transport = new StdioClientTransport({
    command: "node",
    args: ["src/server.js"],
  });

try {
    await client.connect(transport);
    console.log("Client connected successfully");
  } catch (err) {
    console.error("Client connection failed:", err);
    throw err;
  }

// 可选：添加客户端方法调用后的调试
return client;
}

async function getContext(client, question) {
let currentTime = "";
let additionalContext = "";

try {
    const resources = await client.readResource(
      { uri: "time://current" },
      { timeout: 15000 }
    ); // 增加超时时间
    console.log("Resources response:", resources);
    currentTime = resources.contents[0]?.text ||
      newDate().toLocaleString(); // 注意：resources 直接包含 contents
  } catch (err) {
    console.error("Resource read error:", err);
    currentTime = newDate().toLocaleString();
  }

if (question.toLowerCase().includes("公理")) {
    console.log("Searching for axioms...", question);
    try {
      const result = await client.getPrompt({
        name: "search_local_database",
        arguments: { query: question },
      });
      console.log("Tool result:", result);
      additionalContext = result?.[0]?.text || "No results found.";
    } catch (err) {
      console.error("Tool call error:", err);
      additionalContext = "Error searching database.";
    }
  }

return { currentTime, additionalContext };
}

import axios from"axios";

asyncfunction askLLM(prompt) {
try {
    console.log("Calling LLM with prompt:", prompt);
    const res = await axios.post(
      "https://api.deepseek.com/chat/completions",
      {
        model: "deepseek-chat",
        messages: [{ role: "user", content: prompt }],
        max_tokens: 2048,
        stream: false,
        temperature: 0.7,
      },
      {
        headers: {
          Authorization: `Bearer ${process.env.DEEPSEEK_API_KEY}`,
          "Content-Type": "application/json",
        },
        timeout: 1000000,
      }
    );
    console.log("LLM response:", res.data);
    return res.data.choices[0].message.content;
  } catch (err) {
    console.error("LLM error:", err);
    return"Error calling LLM.";
  }
}

// src/index.js
import readline from"readline";
import axios from"axios";

asyncfunction askLLM(prompt) {
try {
    console.log("Calling LLM with prompt:", prompt);
    const res = await axios.post(
      "https://api.deepseek.com/chat/completions",
      {
        model: "deepseek-chat",
        messages: [{ role: "user", content: prompt }],
        max_tokens: 2048,
        stream: false,
        temperature: 0.7,
      },
      {
        headers: {
          Authorization: `Bearer ${process.env.DEEPSEEK_API_KEY}`,
          "Content-Type": "application/json",
        },
        timeout: 1000000,
      }
    );
    console.log("LLM response:", res.data);
    return res.data.choices[0].message.content;
  } catch (err) {
    console.error("LLM error:", err);
    return"Error calling LLM.";
  }
}

asyncfunction getContext(client, question) {
let currentTime = "";
let additionalContext = "";

try {
    const resources = await client.readResource(
      { uri: "time://current" },
      { timeout: 15000 }
    ); // 增加超时时间
    console.log("Resources response:", resources);
    currentTime = resources.contents[0]?.text ||
      newDate().toLocaleString(); // 注意：resources 直接包含 contents
  } catch (err) {
    console.error("Resource read error:", err);
    currentTime = newDate().toLocaleString();
  }

if (question.toLowerCase().includes("公理")) {
    console.log("Searching for axioms...", question);
    try {
      const result = await client.getPrompt({
        name: "search_local_database",
        arguments: { query: question },
      });
      console.log("Tool result:", result);
      additionalContext = result?.[0]?.text || "No results found.";
    } catch (err) {
      console.error("Tool call error:", err);
      additionalContext = "Error searching database.";
    }
  }

return { currentTime, additionalContext };
}

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

const client = await createClient();

while (true) {
const question = awaitnewPromise((resolve) =>
    rl.question("You: ", resolve)
  );
if (question.toLowerCase() === "exit") {
    console.log("Exiting...");
    rl.close();
    process.exit(0);
  }
const context = await getContext(client, question);
const prompt = `Time: ${context.currentTime}\nContext: ${context.additionalContext}\nQ: ${question}\nA:`;
console.log("Prompt:", prompt);
const answer = await askLLM(prompt);
console.log('Assistant:', answer);
}

# 启动服务器
node src/server.js

# 启动客户端
node src/index.js

mcp-mini/
├── package.json
├── src/
│   ├── client.js
│   ├── server.js
│   └── index.js