MCP Serverless Functions Example

import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js"; import { toFetchResponse, toReqRes } from "fetch-to-node"; import { setupMCPServer } from "../mcp-server"; // Netlify serverless function handler export default async (req: Request) => { try{ // Handle different HTTP methods if (req.method === "POST") { return handleMCPPost(req); } else if (req.method === "GET") { return handleMCPGet(); } else if (req.method === "DELETE") { return handleMCPDelete(); } else { return new Response("Method not allowed", { status: 405 }); } } catch (error) { console.error("MCP error:", error); return new Response( JSON.stringify({ jsonrpc: "2.0", error: { code: -32603, message: "Internal server error", }, id: null, }), { status: 500, headers: { "Content-Type": "application/json" } } ); } }; async function handleMCPPost(req: Request) { // Convert the Request object into a Node.js Request object const { req: nodeReq, res: nodeRes } = toReqRes(req); const server = setupMCPServer(); const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined, }); await server.connect(transport); const body = await req.json(); await transport.handleRequest(nodeReq, nodeRes, body); nodeRes.on("close", () => { console.log("Request closed"); transport.close(); server.close(); }); return toFetchResponse(nodeRes); } // For the stateless server, GET requests are used to initialize // SSE connections which are stateful. Therefore, we don't need // to handle GET requests but we can signal to the client this error. function handleMCPGet() { console.log("Received GET MCP request"); return new Response( JSON.stringify({ jsonrpc: "2.0", error: { code: -32000, message: "Method not allowed.", }, id: null, }), { status: 405, headers: { "Content-Type": "application/json" } } ); } function handleMCPDelete() { console.log("Received DELETE MCP request"); return new Response( JSON.stringify({ jsonrpc: "2.0", error: { code: -32000, message: "Method not allowed.", }, id: null, }), { status: 405, headers: { "Content-Type": "application/json" } } ); } // Ensure this function responds to the <domain>/mcp path // This can be any path you want but you'll need to ensure the // mcp server config you use/share matches this path. export const config = { path: "/mcp" };