worker.ts

mcp-server/src/worker.ts

1. import { McpAgent } from "agents/mcp";
2. import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
3. import { registerTools, SERVER_INFO } from "./server.js";
4. import { configFromEnv } from "./lib/config.js";
5. import { WorkerRateLimiter } from "./rateLimiterDO.js";
6. import type { Env } from "./env.js";
8. // Re-export so wrangler can bind the shared rate-limiter Durable Object class.
9. export { RateLimiterDO } from "./rateLimiterDO.js";
11. /**
12. * Cloudflare Workers entry point: remote MCP over HTTP, so the whole company
13. * can connect to one hosted server instead of each person running stdio.
14. *
15. * Built on the Agents SDK `McpAgent`, which is a Durable Object: each client
16. * session is an isolate-backed instance with its own `this.env`. We register the
17. * SAME read-only tool set as the stdio entry, keeping a single source of truth.
18. *
19. * Live requests stay gated (PLINTH_ALLOW_LIVE_REQUESTS) until an operator
20. * deliberately turns them on.
21. */
22. export class PlinthMcp extends McpAgent<Env> {
23. server = new McpServer(SERVER_INFO);
25. async init(): Promise<void> {
26. registerTools(this.server, {
27. config: configFromEnv(this.env),
28. limiter: new WorkerRateLimiter(this.env.RATE_LIMITER),
29. });
30. }
31. }
33. export default {
34. async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
35. const url = new URL(request.url);
37. // Streamable HTTP transport (current MCP standard). The Durable Object
38. // binding is named PLINTH_MCP in wrangler.jsonc, not the SDK default MCP_OBJECT.
39. if (url.pathname === "/mcp") {
40. return PlinthMcp.serve("/mcp", { binding: "PLINTH_MCP" }).fetch(request, env, ctx);
41. }
43. // SSE transport (legacy clients).
44. if (url.pathname === "/sse" || url.pathname === "/sse/message") {
45. return PlinthMcp.serveSSE("/sse", { binding: "PLINTH_MCP" }).fetch(request, env, ctx);
46. }
48. if (url.pathname === "/health") {
49. return Response.json({ status: "ok", server: SERVER_INFO });
50. }
52. return new Response("Not found", { status: 404 });
53. },
54. };
56. // Unauthenticated: see "Next steps" in the server README before exposing real data.