MCP Server with OpenAI Integration

import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { CallToolRequestSchema, ListToolsRequestSchema, Tool, } from "@modelcontextprotocol/sdk/types.js"; import { z } from "zod"; // Custom tool schema const WeatherToolSchema = z.object({ city: z.string().describe("The city to get weather information for"), unit: z.enum(["celsius", "fahrenheit"]).optional().default("celsius").describe("Temperature unit"), }); // Custom tool implementation async function getWeatherInfo(city: string, unit: "celsius" | "fahrenheit" = "celsius"): Promise<string> { // Simulate weather API call const temperature = Math.floor(Math.random() * 30) + 10; // Random temp between 10-40 const conditions = ["sunny", "cloudy", "rainy", "partly cloudy"]; const condition = conditions[Math.floor(Math.random() * conditions.length)]; const tempDisplay = unit === "fahrenheit" ? `${Math.round(temperature * 9/5 + 32)}°F` : `${temperature}°C`; return `Weather in ${city}: ${tempDisplay}, ${condition}`; } // Define the custom tool const weatherTool: Tool = { name: "get_weather", description: "Get current weather information for a specific city", inputSchema: { type: "object", properties: { city: { type: "string", description: "The city to get weather information for" }, unit: { type: "string", enum: ["celsius", "fahrenheit"], default: "celsius", description: "Temperature unit" } }, required: ["city"] }, }; class CustomMCPServer { private server: Server; constructor() { this.server = new Server( { name: "custom-mcp-server", version: "1.0.0", } ); this.setupToolHandlers(); } private setupToolHandlers() { // Handle tool listing this.server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: [weatherTool], }; }); // Handle tool calls this.server.setRequestHandler(CallToolRequestSchema, async (request) => { const { name, arguments: args } = request.params; switch (name) { case "get_weather": const { city, unit } = WeatherToolSchema.parse(args); const weatherInfo = await getWeatherInfo(city, unit); return { content: [ { type: "text", text: weatherInfo, }, ], }; default: throw new Error(`Unknown tool: ${name}`); } }); } async run() { const transport = new StdioServerTransport(); await this.server.connect(transport); console.error("Custom MCP Server started"); } } // Start the server const server = new CustomMCPServer(); server.run().catch(console.error);