import express from 'express';
import cors from 'cors';
import { config } from 'dotenv';
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { SSEServerTransport } from '@modelcontextprotocol/sdk/server/sse.js';
import {
CallToolRequestSchema,
ListToolsRequestSchema,
Tool,
} from '@modelcontextprotocol/sdk/types.js';
// 加载环境变量
config();
const PORT = process.env.PORT || 8000;
const OPERATOR_NAME = process.env.OPERATOR_NAME;
// 验证必需的环境变量
function validateEnvironment(): void {
if (!OPERATOR_NAME) {
console.error('❌ 错误：缺少必需的环境变量 OPERATOR_NAME（启动者姓名）');
console.error('\n请设置环境变量：');
console.error('1. 创建 .env 文件：');
console.error(' OPERATOR_NAME=张三');
console.error(' PORT=8000');
console.error('\n2. 或者在启动时设置：');
console.error(' OPERATOR_NAME=张三 npm start');
process.exit(1);
}
console.log('✅ 环境变量验证通过');
console.log(` 启动者: ${OPERATOR_NAME}`);
console.log(` 端口: ${PORT}`);
}
// 启动前验证
validateEnvironment();
// 定义计算器工具
const TOOLS: Tool[] = [
{
name: 'add',
description: '加法运算：计算两个数的和',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '第一个数字',
},
b: {
type: 'number',
description: '第二个数字',
},
},
required: ['a', 'b'],
},
},
{
name: 'subtract',
description: '减法运算：计算两个数的差',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '被减数',
},
b: {
type: 'number',
description: '减数',
},
},
required: ['a', 'b'],
},
},
{
name: 'multiply',
description: '乘法运算：计算两个数的积',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '第一个数字',
},
b: {
type: 'number',
description: '第二个数字',
},
},
required: ['a', 'b'],
},
},
{
name: 'divide',
description: '除法运算：计算两个数的商',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '被除数',
},
b: {
type: 'number',
description: '除数（不能为0）',
},
},
required: ['a', 'b'],
},
},
{
name: 'power',
description: '幂运算：计算 a 的 b 次方',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '底数',
},
b: {
type: 'number',
description: '指数',
},
},
required: ['a', 'b'],
},
},
{
name: 'sqrt',
description: '平方根运算：计算一个数的平方根',
inputSchema: {
type: 'object',
properties: {
a: {
type: 'number',
description: '需要计算平方根的数字（非负数）',
},
},
required: ['a'],
},
},
{
name: 'factorial',
description: '阶乘运算：计算一个非负整数的阶乘',
inputSchema: {
type: 'object',
properties: {
n: {
type: 'number',
description: '需要计算阶乘的非负整数',
},
},
required: ['n'],
},
},
{
name: 'get_operator_info',
description: '获取服务器启动者信息',
inputSchema: {
type: 'object',
properties: {},
},
},
];
// 计算阶乘的辅助函数
function factorial(n: number): number {
if (n < 0 || !Number.isInteger(n)) {
throw new Error('阶乘只能计算非负整数');
}
if (n === 0 || n === 1) return 1;
let result = 1;
for (let i = 2; i <= n; i++) {
result *= i;
}
return result;
}
// 创建 MCP 服务器实例
function createMCPServer(): Server {
const server = new Server(
{
name: 'mcp-calculator',
version: '1.0.1',
},
{
capabilities: {
tools: {},
},
}
);
// 处理工具列表请求
server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: TOOLS,
};
});
// 处理工具调用请求
server.setRequestHandler(CallToolRequestSchema, async (request) => {
const { name, arguments: args } = request.params;
try {
let result: number;
switch (name) {
case 'add': {
const a = args?.a as number;
const b = args?.b as number;
result = a + b;
return {
content: [
{
type: 'text',
text: `${a} + ${b} = ${result}`,
},
],
};
}
case 'subtract': {
const a = args?.a as number;
const b = args?.b as number;
result = a - b;
return {
content: [
{
type: 'text',
text: `${a} - ${b} = ${result}`,
},
],
};
}
case 'multiply': {
const a = args?.a as number;
const b = args?.b as number;
result = a * b;
return {
content: [
{
type: 'text',
text: `${a} × ${b} = ${result}`,
},
],
};
}
case 'divide': {
const a = args?.a as number;
const b = args?.b as number;
if (b === 0) {
throw new Error('除数不能为零');
}
result = a / b;
return {
content: [
{
type: 'text',
text: `${a} ÷ ${b} = ${result}`,
},
],
};
}
case 'power': {
const a = args?.a as number;
const b = args?.b as number;
result = Math.pow(a, b);
return {
content: [
{
type: 'text',
text: `${a}^${b} = ${result}`,
},
],
};
}
case 'sqrt': {
const a = args?.a as number;
if (a < 0) {
throw new Error('不能计算负数的平方根');
}
result = Math.sqrt(a);
return {
content: [
{
type: 'text',
text: `√${a} = ${result}`,
},
],
};
}
case 'factorial': {
const n = args?.n as number;
result = factorial(n);
return {
content: [
{
type: 'text',
text: `${n}! = ${result}`,
},
],
};
}
case 'get_operator_info': {
const info = {
operatorName: OPERATOR_NAME,
serverName: 'mcp-calculator',
version: '1.0.1',
port: PORT,
startTime: new Date().toLocaleString('zh-CN', {
timeZone: 'Asia/Shanghai',
}),
};
return {
content: [
{
type: 'text',
text: `服务器信息:\n${JSON.stringify(info, null, 2)}`,
},
],
};
}
default:
throw new Error(`未知工具: ${name}`);
}
} catch (error) {
const errorMessage = error instanceof Error ? error.message : String(error);
return {
content: [
{
type: 'text',
text: `错误: ${errorMessage}`,
},
],
isError: true,
};
}
});
return server;
}
// 启动 Express 服务器
async function main() {
const app = express();
// 启用 CORS
app.use(cors());
app.use(express.json());
// 健康检查端点
app.get('/health', (req, res) => {
res.json({
status: 'ok',
service: 'mcp-calculator',
version: '1.0.1',
operator: OPERATOR_NAME,
port: PORT,
timestamp: new Date().toISOString(),
});
});
// SSE 端点
app.get('/sse', async (req, res) => {
console.log('新的 SSE 连接');
// 设置 SSE 响应头
res.setHeader('Content-Type', 'text/event-stream');
res.setHeader('Cache-Control', 'no-cache');
res.setHeader('Connection', 'keep-alive');
// 创建 MCP 服务器实例
const mcpServer = createMCPServer();
// 创建 SSE transport
const transport = new SSEServerTransport('/message', res);
// 连接服务器和 transport
await mcpServer.connect(transport);
console.log('MCP 服务器已通过 SSE 连接');
// 处理连接关闭
req.on('close', () => {
console.log('SSE 连接已关闭');
mcpServer.close();
});
});
// POST 端点用于接收客户端消息
app.post('/message', async (req, res) => {
// 这个端点会被 SSE transport 自动处理
res.json({ status: 'ok' });
});
// 启动服务器
app.listen(PORT, () => {
console.log('\n=================================');
console.log('🚀 MCP 计算器服务器已启动');
console.log('=================================');
console.log(`👤 启动者: ${OPERATOR_NAME}`);
console.log(`🌐 服务地址: http://localhost:${PORT}`);
console.log(`📡 SSE 端点: http://localhost:${PORT}/sse`);
console.log(`❤️ 健康检查: http://localhost:${PORT}/health`);
console.log(`⏰ 启动时间: ${new Date().toLocaleString('zh-CN')}`);
console.log('=================================\n');
});
}
main().catch((error) => {
console.error('服务器错误:', error);
process.exit(1);
});
