MCPAuth

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'; import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js'; import { isInitializeRequest } from '@modelcontextprotocol/sdk/types.js'; import { toFetchResponse, toReqRes } from 'fetch-to-node'; import { createFetchTool } from './lib/fetch.tool'; import { createSearchTool } from './lib/search.tool'; // McpSession - Durable Object for managing a single MCP session export class McpSession { state: DurableObjectState; transport?: StreamableHTTPServerTransport; server?: McpServer; env: CloudflareBindings; constructor(state: DurableObjectState, env: CloudflareBindings) { this.state = state; this.env = env; } async initialize() { const transport = new StreamableHTTPServerTransport({ // The session ID is the durable object's ID sessionIdGenerator: () => this.state.id.toString(), }); const server = new McpServer({ name: 'hono-mcp-server', version: '1.0.0', }); createSearchTool(server); createFetchTool(server); await server.connect(transport); this.transport = transport; this.server = server; } async fetch(request: Request) { // Each Durable Object instance has its own in-memory state, // so we can just check if we've initialized the transport yet. if (!this.transport) { const body = await request.clone().json(); if (isInitializeRequest(body)) { await this.initialize(); } else { // If it's not an initialize request and we're not initialized, // it's a bad request. return new Response('Bad Request: Session not initialized', { status: 400 }); } } // Forward the request to the transport // The transport expects Node.js-style req/res objects, so we convert. const { req, res } = toReqRes(request); // eslint-disable-next-line @typescript-eslint/no-non-null-assertion // eslint-disable-next-line @typescript-eslint/no-non-null-assertion await this.transport!.handleRequest(req, res); // Convert the Node.js-style response back to a Fetch API Response return toFetchResponse(res); } }