☕ coffee.openworklabs.com/sf

Grab a coffee with the OpenWork team in San Francisco, from inside your agent.

Add one URL to Claude Code, Cursor, Codex, OpenWork or any MCP client, then say "grab a coffee with OpenWork." A small 3D San Francisco café opens right in the chat (MCP Apps). Put your email address in it, confirm the email, and you get a time, a place and a calendar invite. The team gets a post in #coffee-requests.

Add it to your agent

No API key, no sign-in. The URL is https://coffee.openworklabs.com/sf.

Opening the same URL in a browser shows the landing page with the same 3D card, so it works without an agent too.

Related MCP server: Google Calendar Meeting Setup

How it works

agent ──grab_coffee──▶ Worker (/sf) ──▶ 3D card (ui://coffee/sf.html)
                          │
person puts email ────────┤──▶ confirmation email (Resend)
                          │
person taps confirm ──────┴──▶ next open slot ─▶ invite + .ics ─▶ #coffee-requests
                                                     ▲
                       the card in chat flips to "You're on for coffee" on its own

Design choices:

• The email is confirmed before anything is booked, so nobody can book coffee for someone else's address. The confirm link opens a page with a button; visiting it alone books nothing, so email link scanners can't confirm.

• One proposed time, the next free weekday slot (10:00, 14:00 or 16:00 PT, at least 18 hours out). Two people never get the same slot. "Can't make it?" is a reply to the email.

• Rate limits per email (3 a day) and per IP (20 an hour).

• One self-contained HTML file (Three.js, no external requests) serves as both the MCP App resource and the landing page, so the default MCP Apps CSP is enough. It respects prefers-reduced-motion, pauses when off screen, and stacks the card under the scene on phones.

• Hosts without MCP Apps still work: the tool text tells the agent to ask for the email.

Full experience design: docs/DESIGN.md.

Develop

pnpm install
cp .dev.vars.example .dev.vars   # DEV_MODE=1 shows a "Dev: confirm link" instead of emailing
pnpm dev                         # http://localhost:8787/sf
pnpm test                        # unit + MCP-over-HTTP + web flow tests
pnpm typecheck

Try it from an agent locally: claude mcp add --transport http coffee-dev http://localhost:8787/sf.

Deploy (Cloudflare)

pnpm wrangler login
pnpm wrangler secret put RESEND_API_KEY      # sends from EMAIL_FROM; verify the domain in Resend
pnpm wrangler secret put SLACK_WEBHOOK_URL   # see slack-app-manifest.yaml
pnpm wrangler secret put HOST_EMAIL          # optional: CC'd on every invite
pnpm deploy

wrangler.jsonc binds the custom domain coffee.openworklabs.com (the openworklabs.com zone must be in the same Cloudflare account) and provisions the COFFEE_KV namespace on first deploy. Host name, café, time zone and sender live in vars.

Slack

Bookings post to #coffee-requests. Create the app from slack-app-manifest.yaml, install it to #coffee-requests, and save the webhook as SLACK_WEBHOOK_URL. A bot token works too: set SLACK_BOT_TOKEN and SLACK_CHANNEL_ID.

Layout

app/        the 3D view (Three.js + @modelcontextprotocol/ext-apps), built to dist/app.html
src/        the Worker: MCP server, booking logic, email, Slack, calendar
test/       vitest

MIT licensed.