CMU Courses — Claude Connector

A remote MCP connector that gives Claude live, structured access to CMU Courses public data so it can help students plan schedules with accurate course info: courses, units, descriptions, prerequisites/corequisites/crosslists, requisite trees, offered schedules (times, instructors, locations), instructor teaching history, gen-eds, and final-exam times.

• Read-only wrapper of the existing CMU Courses public API — it does not modify or run any part of the CMU Courses codebase.

• Stateless, authless, deployed to Cloudflare Workers (Streamable HTTP, MCP).

• Backend: https://course.apis.scottylabs.org (the live ScottyLabs course backend).

FCE (course evaluations / workload / ratings) is not included in this version. That data is sign-in-gated behind Clerk, and a remote connector can't reach a user's browser session. See src/auth/authProvider.ts for the deferred design.

Tools

Related MCP server: scottylabs-mcp

Develop

npm install
npm run typecheck        # tsc --noEmit
npm test                 # unit tests (mocked backend) — 38 tests
npm run test:integration # live contract tests against the real backend
npm run dev              # wrangler dev on http://127.0.0.1:8787/mcp

Drive it locally with the MCP Inspector:

npm run inspector        # then connect to http://127.0.0.1:8787/mcp (transport: Streamable HTTP)

Or with Claude Code:

claude mcp add --transport http cmucourses http://127.0.0.1:8787/mcp

Stress test (mixed tools, live backend):

node scripts/stress.mjs http://127.0.0.1:8787/mcp 50 200

Deploy (Cloudflare Workers)

npx wrangler login          # one-time, uses your Cloudflare account
npx wrangler deploy         # -> https://cmucourses-connector.<your-subdomain>.workers.dev

The backend URL is set in wrangler.jsonc (vars.CMU_COURSES_BACKEND_URL) and can be overridden per environment. An optional KV cache for the large /courses/all and /instructors lists is documented (commented) in wrangler.jsonc; the connector also caches these in-isolate by default, so KV is optional.

Register in Claude

Live deployment: https://cmucourses-connector.samethanmathew.workers.dev/mcp

1. Settings → Connectors → Add custom connector.

2. Paste the URL above (note the /mcp path).

3. No login is required (public data). The tools appear immediately.

Maintaining the finals snapshot

src/reference/finals.snapshot.json is a per-semester copy of the CMU Courses finals data (currently Fall 2025). When the semester changes, replace it from cmucourses/apps/frontend/src/components/finals/finals.json and update SEMESTER_LABEL in src/tools/finals.ts.

Layout

src/
  index.ts              Worker entry + createServer()
  mcp/                  Minimal MCP server (JSON-RPC) + Streamable-HTTP transport
  backend/              CMU Courses API client (encoding, normalization, retries, cache)
  tools/                One module per tool group
  reference/            Departments, gened schools, day map, finals snapshot
  auth/                 Deferred FCE seam (not wired in v1)
test/                   Unit + live integration/contract tests
scripts/stress.mjs      Concurrency load test
docs/EVALS.md           Golden-answer eval prompts