ExpressJS MCP

/** * Example 03: Custom Exposed Endpoints * * This example shows how to selectively expose only certain routes as MCP tools * using include/exclude filters. */ import express from "express"; import { ExpressMCP } from "../../src"; const app = express(); app.use(express.json()); // Sample routes app.get("/public/hello", (_req, res) => res.json({ message: "Hello, public!" }), ); app.get("/public/status", (_req, res) => res.json({ status: "ok" })); app.get("/admin/users", (_req, res) => res.json({ users: ["admin", "user1"] })); app.post("/admin/users", (req, res) => res.status(201).json({ id: "u1", ...req.body }), ); app.get("/api/data", (_req, res) => res.json({ data: "sensitive" })); app.post("/api/data", (req, res) => res.json({ processed: req.body })); // Create different MCP instances with different configurations // 1. Default (all routes) const mcp = new ExpressMCP(app, { mountPath: "/mcp" }); // 2. Whitelist approach (only specific routes) const mcpWhitelist = new ExpressMCP(app, { mountPath: "/mcp-whitelist", include: (route) => { // Only include public routes return route.path.startsWith("/public/"); }, }); // 3. Pattern-based approach (exclude certain patterns) const mcpPatterns = new ExpressMCP(app, { mountPath: "/mcp-patterns", exclude: (route) => { // Exclude admin routes return route.path.startsWith("/admin/"); }, }); // Initialize all MCP instances await Promise.all([mcp.init(), mcpWhitelist.init(), mcpPatterns.init()]); // Mount all MCP endpoints mcp.mount("/mcp"); mcpWhitelist.mount("/mcp-whitelist"); mcpPatterns.mount("/mcp-patterns"); const PORT = 3002; app.listen(PORT, () => { console.log(`✅ Express server running on http://localhost:${PORT}`); console.log("\n🔧 MCP Endpoints:"); console.log("1️⃣ Default approach (/mcp):"); console.log(` Found ${mcp.listTools().length} tools:`); for (const tool of mcp.listTools()) { const toolObj = tool as { title: string }; console.log(` - ${toolObj.title}`); } console.log("\n2️⃣ Whitelist approach (/mcp-whitelist):"); console.log(` Found ${mcpWhitelist.listTools().length} tools:`); for (const tool of mcpWhitelist.listTools()) { const toolObj = tool as { title: string }; console.log(` - ${toolObj.title}`); } console.log("\n3️⃣ Pattern-based (/mcp-patterns):"); console.log(` Found ${mcpPatterns.listTools().length} tools:`); for (const tool of mcpPatterns.listTools()) { const toolObj = tool as { title: string }; console.log(` - ${toolObj.title}`); } console.log("\n🔍 Test the different endpoints:"); console.log(` curl http://localhost:${PORT}/mcp/tools`); console.log(` curl http://localhost:${PORT}/mcp-whitelist/tools`); console.log(` curl http://localhost:${PORT}/mcp-patterns/tools`); });