index.ts

import { createMcpHandler } from "agents/mcp";
import { parseConfig, createClient, type Env } from "./config.js";
import { createServer } from "./server.js";

const CORS_ORIGIN = "*";
const CORS_METHODS = "GET, POST, DELETE, OPTIONS";
const CORS_ALLOWED_HEADERS =
  "Content-Type, Authorization, X-Honcho-User-Name, X-Honcho-Workspace-ID, X-Honcho-Assistant-Name";

const CORS_HEADERS = {
  "Access-Control-Allow-Origin": CORS_ORIGIN,
  "Access-Control-Allow-Methods": CORS_METHODS,
  "Access-Control-Allow-Headers": CORS_ALLOWED_HEADERS,
};

function stripOAuthChallenge(response: Response): Response {
  if (!response.headers.has("WWW-Authenticate")) return response;
  const headers = new Headers(response.headers);
  headers.delete("WWW-Authenticate");
  return new Response(response.body, {
    status: response.status,
    statusText: response.statusText,
    headers,
  });
}

export default {
  async fetch(
    request: Request,
    env: Env,
    executionCtx: ExecutionContext,
  ): Promise<Response> {
    if (request.method === "OPTIONS") {
      return new Response(null, { status: 204, headers: CORS_HEADERS });
    }

    let config;
    try {
      config = parseConfig(request, env);
    } catch (e) {
      const message =
        e instanceof Error ? e.message : "Invalid request";
      return new Response(JSON.stringify({ error: message }), {
        status: 401,
        headers: { "Content-Type": "application/json", ...CORS_HEADERS },
      });
    }

    try {
      const honcho = createClient(config);
      const server = createServer({ honcho, config });
      const handler = createMcpHandler(server, {
        route: "/",
        corsOptions: {
          origin: CORS_ORIGIN,
          methods: CORS_METHODS,
          headers: CORS_ALLOWED_HEADERS,
        },
      });
      return stripOAuthChallenge(await handler(request, env, executionCtx));
    } catch (e) {
      const message =
        e instanceof Error ? e.message : "Internal server error";
      return new Response(JSON.stringify({ error: message }), {
        status: 500,
        headers: { "Content-Type": "application/json", ...CORS_HEADERS },
      });
    }
  },
};