MCP TypeScript SDK 
目录
- 回声服务器 - SQLite资源管理器
概述
模型上下文协议允许应用程序以标准化的方式为LLM提供上下文，将提供上下文的关注点与实际的LLM交互分开。此TypeScript SDK实现了完整的MCP规范，使其易于：
- 构建可以连接到任何MCP服务器的MCP客户端
- 创建公开资源、提示和工具的MCP服务器
- 使用标准传输方式，如stdio和SSE
- 处理所有MCP协议消息和生命周期事件
安装
npm install @modelcontextprotocol/sdk快速开始
让我们创建一个简单的MCP服务器，它公开了一个计算器工具和一些数据：
import { McpServer, ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";
// Create an MCP server
const server = new McpServer({
name: "Demo",
version: "1.0.0"
});
// Add an addition tool
server.tool("add",
{ a: z.number(), b: z.number() },
async ({ a, b }) => ({
content: [{ type: "text", text: String(a + b) }]
})
);
// Add a dynamic greeting resource
server.resource(
"greeting",
new ResourceTemplate("greeting://{name}", { list: undefined }),
async (uri, { name }) => ({
contents: [{
uri: uri.href,
text: `Hello, ${name}!`
}]
})
);
// Start receiving messages on stdin and sending messages on stdout
const transport = new StdioServerTransport();
await server.connect(transport);什么是MCP？
这 模型上下文协议（MCP） 允许您构建以安全、标准化的方式向LLM应用程序公开数据和功能的服务器。将其视为一个web API，但它是专门为LLM交互而设计的。MCP服务器可以：
- 通过以下方式公开数据 资源 （将这些类似于GET端点；它们用于将信息加载到LLM的上下文中）
- 通过以下方式提供功能 工具 （有点像POST端点；它们用于执行代码或产生副作用）
- 通过以下方式定义交互模式 鼓励 （LLM交互的可重用模板）
- 还有更多！
核心概念
服务器
McpServer是MCP协议的核心接口。它处理连接管理、协议合规性和消息路由：
const server = new McpServer({
name: "My App",
version: "1.0.0"
});资源
资源是您向LLM公开数据的方式。它们类似于REST API中的GET端点-它们提供数据，但不应执行显著的计算或产生副作用：
// Static resource
server.resource(
"config",
"config://app",
async (uri) => ({
contents: [{
uri: uri.href,
text: "App configuration here"
}]
})
);
// Dynamic resource with parameters
server.resource(
"user-profile",
new ResourceTemplate("users://{userId}/profile", { list: undefined }),
async (uri, { userId }) => ({
contents: [{
uri: uri.href,
text: `Profile data for user ${userId}`
}]
})
);工具
工具允许LLM通过您的服务器执行操作。与资源不同，工具被期望执行计算并具有副作用：
// Simple tool with parameters
server.tool(
"calculate-bmi",
{
weightKg: z.number(),
heightM: z.number()
},
async ({ weightKg, heightM }) => ({
content: [{
type: "text",
text: String(weightKg / (heightM * heightM))
}]
})
);
// Async tool with external API call
server.tool(
"fetch-weather",
{ city: z.string() },
async ({ city }) => {
const response = await fetch(`https://api.weather.com/${city}`);
const data = await response.text();
return {
content: [{ type: "text", text: data }]
};
}
);鼓励
提示是可重用的模板，可帮助LLM与您的服务器有效交互：
server.prompt(
"review-code",
{ code: z.string() },
({ code }) => ({
messages: [{
role: "user",
content: {
type: "text",
text: `Please review this code:\n\n${code}`
}
}]
})
);运行服务器
TypeScript中的MCP服务器需要连接到传输设备才能与客户端通信。如何启动服务器取决于传输方式的选择：
标准输入输出
对于命令行工具和直接集成：
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
const server = new McpServer({
name: "example-server",
version: "1.0.0"
});
// ... set up server resources, tools, and prompts ...
const transport = new StdioServerTransport();
await server.connect(transport);HTTP与SSE
对于远程服务器，使用服务器发送事件（SSE）端点和单独的端点启动web服务器，以便客户端将其消息发送到：
import express, { Request, Response } from "express";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
const server = new McpServer({
name: "example-server",
version: "1.0.0"
});
// ... set up server resources, tools, and prompts ...
const app = express();
// to support multiple simultaneous connections we have a lookup object from
// sessionId to transport
const transports: {[sessionId: string]: SSEServerTransport} = {};
app.get("/sse", async (_: Request, res: Response) => {
const transport = new SSEServerTransport('/messages', res);
transports[transport.sessionId] = transport;
res.on("close", () => {
delete transports[transport.sessionId];
});
await server.connect(transport);
});
app.post("/messages", async (req: Request, res: Response) => {
const sessionId = req.query.sessionId as string;
const transport = transports[sessionId];
if (transport) {
await transport.handlePostMessage(req, res);
} else {
res.status(400).send('No transport found for sessionId');
}
});
app.listen(3001);测试和调试
要测试您的服务器，您可以使用 MCP检查员。有关更多信息，请参阅其README。
例子
回声服务器
一个简单的服务器，演示资源、工具和提示：
import { McpServer, ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
const server = new McpServer({
name: "Echo",
version: "1.0.0"
});
server.resource(
"echo",
new ResourceTemplate("echo://{message}", { list: undefined }),
async (uri, { message }) => ({
contents: [{
uri: uri.href,
text: `Resource echo: ${message}`
}]
})
);
server.tool(
"echo",
{ message: z.string() },
async ({ message }) => ({
content: [{ type: "text", text: `Tool echo: ${message}` }]
})
);
server.prompt(
"echo",
{ message: z.string() },
({ message }) => ({
messages: [{
role: "user",
content: {
type: "text",
text: `Please process this message: ${message}`
}
}]
})
);SQLite资源管理器
一个更复杂的数据库集成示例：
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import sqlite3 from "sqlite3";
import { promisify } from "util";
import { z } from "zod";
const server = new McpServer({
name: "SQLite Explorer",
version: "1.0.0"
});
// Helper to create DB connection
const getDb = () => {
const db = new sqlite3.Database("database.db");
return {
all: promisify(db.all.bind(db)),
close: promisify(db.close.bind(db))
};
};
server.resource(
"schema",
"schema://main",
async (uri) => {
const db = getDb();
try {
const tables = await db.all(
"SELECT sql FROM sqlite_master WHERE type='table'"
);
return {
contents: [{
uri: uri.href,
text: tables.map((t: {sql: string}) => t.sql).join("\n")
}]
};
} finally {
await db.close();
}
}
);
server.tool(
"query",
{ sql: z.string() },
async ({ sql }) => {
const db = getDb();
try {
const results = await db.all(sql);
return {
content: [{
type: "text",
text: JSON.stringify(results, null, 2)
}]
};
} catch (err: unknown) {
const error = err as Error;
return {
content: [{
type: "text",
text: `Error: ${error.message}`
}],
isError: true
};
} finally {
await db.close();
}
}
);高级用法
低级服务器
为了获得更多控制，您可以直接使用低级Server类：
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
ListPromptsRequestSchema,
GetPromptRequestSchema
} from "@modelcontextprotocol/sdk/types.js";
const server = new Server(
{
name: "example-server",
version: "1.0.0"
},
{
capabilities: {
prompts: {}
}
}
);
server.setRequestHandler(ListPromptsRequestSchema, async () => {
return {
prompts: [{
name: "example-prompt",
description: "An example prompt template",
arguments: [{
name: "arg1",
description: "Example argument",
required: true
}]
}]
};
});
server.setRequestHandler(GetPromptRequestSchema, async (request) => {
if (request.params.name !== "example-prompt") {
throw new Error("Unknown prompt");
}
return {
description: "Example prompt",
messages: [{
role: "user",
content: {
type: "text",
text: "Example prompt text"
}
}]
};
});
const transport = new StdioServerTransport();
await server.connect(transport);编写MCP客户端
SDK提供了一个高级客户端接口：
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
const transport = new StdioClientTransport({
command: "node",
args: ["server.js"]
});
const client = new Client(
{
name: "example-client",
version: "1.0.0"
},
{
capabilities: {
prompts: {},
resources: {},
tools: {}
}
}
);
await client.connect(transport);
// List prompts
const prompts = await client.listPrompts();
// Get a prompt
const prompt = await client.getPrompt("example-prompt", {
arg1: "value"
});
// List resources
const resources = await client.listResources();
// Read a resource
const resource = await client.readResource("file:///example.txt");
// Call a tool
const result = await client.callTool({
name: "example-tool",
arguments: {
arg1: "value"
}
});文档
贡献
问题和拉取请求欢迎在GitHub上发布https://github.com/modelcontextprotocol/typescript-sdk.
许可证
该项目根据MIT许可证获得许可——请参阅 许可证 文件以获取详细信息。