Express MCP Server

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js"; import { randomUUID } from "node:crypto"; import type { IncomingMessage, ServerResponse } from "node:http"; import type * as z from "zod"; export type ToolHandler = (args: Record<string, unknown>) => Promise<string>; export interface ToolConfig { name: string; description: string; inputSchema: Record<string, z.ZodSchema>; handler: ToolHandler; } export class MCP { private server: McpServer; private transport: StreamableHTTPServerTransport; private connected = false; constructor() { this.transport = new StreamableHTTPServerTransport({ sessionIdGenerator: () => randomUUID(), }); this.server = new McpServer({ name: "express-mcp-server", version: "1.0.0", }); } registerTool(config: ToolConfig): void { this.server.registerTool( config.name, { title: config.name, description: config.description, inputSchema: config.inputSchema, }, async (args) => { const result = await config.handler(args as Record<string, unknown>); return { content: [{ type: "text" as const, text: result }], }; }, ); } async handleRequest( req: IncomingMessage, res: ServerResponse, body?: unknown, ): Promise<void> { if (!this.connected) { await this.server.connect(this.transport); this.connected = true; } await this.transport.handleRequest(req, res, body); } }