Two overlapping bugs were killing OAuth discovery for every external MCP client (Claude Desktop, Cursor, etc.): 1. worker.ts injected PUBLIC_URL=http://<RUNNER_HOST>:<port> into the runner container even when MCP_DOMAIN was set. Result: the runner's /.well-known/oauth-protected-resource advertised an unreachable URL and the WWW-Authenticate header pointed at a non-HTTPS loopback address. Claude Desktop refused to follow the discovery chain. Now derives PUBLIC_URL from the same computePublicUrl() helper that builds the user-visible URL stored in mcp_servers.public_url, so the container's self-reported resource matches its actual route. 2. docker-compose.prod.yml never mounted /opt/buildmymcpserver/runner-map into the api / generator containers. The .conf snippet written by the generator landed in an ephemeral container path; the host inotify watcher saw an empty directory and produced an empty runner-map.combined. Result: nginx 404'd every /<slug>/* request, the runner was unreachable from the public domain, and OAuth discovery couldn't even begin. Mount added to both services. Existing weather server has the wrong PUBLIC_URL baked in and must be recreated after deploy. No customers yet. export computePublicUrl from deploy.ts so worker.ts can call it.
BuildMyMCPServer
Describe your tool. We host the server. AI uses it.
Prompt-to-production MCP servers with OAuth 2.1 and Streamable HTTP. Production-grade infrastructure for hosting Model Context Protocol servers your AI clients (Claude Desktop, Cursor, ChatGPT) can install with a copy-paste snippet.
Quick start
# 1. Install
pnpm install
# 2. Copy env. Defaults work for local dev. Set ANTHROPIC_API_KEY if you want real generation.
cp .env.example .env
# 3. Boot everything
pnpm dev
pnpm dev will:
- Load
.env. docker compose up -d --waitpostgres + redis.- Push the Drizzle schema (
drizzle-kit push --force). - Start the full stack in parallel: web (Next.js, :3000), api (Fastify, :4000), generator (BullMQ worker).
Then open:
- Dashboard: http://localhost:3000
- API: http://localhost:4000/health
Click Start building, enter your email, copy the magic-link URL printed to the
api terminal output, paste it in your browser. You land on /dashboard. Click
New server, paste a prompt, and watch the build stream live over WebSocket.
If ANTHROPIC_API_KEY is unset, the generator returns a deterministic mock spec
(an echo and a now tool) so the full end-to-end flow stays demoable.
If Docker is unavailable, the build will fail at the deploy step with a clear error.
Otherwise: a fresh container is launched on a host port from
RUNNER_PORT_RANGE_START…RUNNER_PORT_RANGE_END, the server is marked live, and the
dashboard renders install snippets for Claude Desktop, Cursor and ChatGPT.
Architecture
See BuildMyMCPServer_MASTER_PROMPT.md for the full specification and CHOICES.md
for decisions made during this Sprints 1–3 build.
apps/
web/ Next.js 15 dashboard + marketing landing
api/ Fastify control plane (auth, server CRUD, OAuth 2.1 AS, JWKS, WS stream)
generator/ BullMQ worker — Claude → spec → render → docker build → local deploy
runner-template/ Hosted MCP server template (Streamable HTTP + OAuth 2.1 RS)
packages/
db/ Drizzle schema + client
auth/ Magic-link + session
types/ Shared Zod contracts
Scripts
| Command | Effect |
|---|---|
pnpm dev |
Bootstrap + parallel dev for web, api, generator |
pnpm dev:no-docker |
Skip docker-compose (assumes postgres + redis already up) |
pnpm build |
Turbo build all apps |
pnpm typecheck |
Turbo typecheck all apps |
pnpm lint |
Biome check |
pnpm lint:fix |
Biome check --write |
pnpm db:push |
Push schema to postgres (drizzle-kit) |
pnpm db:generate |
Generate SQL migration files |
pnpm db:migrate |
Apply pending migrations |
pnpm stop |
docker compose down |
Acceptance check
After pnpm dev is up:
http://localhost:3000renders the landing page.http://localhost:4000/healthreturns{ "ok": true }.- Sign in via magic link (URL printed in the api terminal).
- New Server → paste prompt → live WebSocket stream
queued → generating → building → deploying → live. - If Docker is running, a container is launched and
http://localhost:<port>/mcpresponds 401 + WWW-Authenticate without a token, 200 with a valid token issued by/oauth/token. - Install snippets render with copy buttons for Claude Desktop, Cursor, ChatGPT.
Repo conventions
- TypeScript strict, zero
any(Biome lintsnoExplicitAnyas error). - ESM-only, Node 20 LTS.
- Conventional commits.
- Tailwind v4 (
@import 'tailwindcss'). - Geist + Geist Mono.