Appointment booking that an AI receptionist can use
Noonbell is open-source booking software for small firms that book time with clients. Clients book on your booking page. An AI receptionist or phone agent books through the API. Both use the same hours, the same rules and the same calendar.
Not launched yet. Early access is coming soon.
Who it is for
Small firms that book time with clients: law firms, accounting firms, financial advisors and other professional services.
Noonbell is not for healthcare. It does not support clinics, dental offices, therapy practices or any business that stores protected health information, and it has no HIPAA setup.
Features
Booking pages
Set services, staff and weekly hours. Clients pick an open time and get a confirmation email with a calendar file.
Google Calendar sync
Busy time on the Google calendars you choose is removed from open slots. Each booking goes onto the one calendar you pick.
Email reminders
Reminders go out 24 hours and 2 hours before the visit. Each email has links to reschedule or cancel.
Security
Two-factor sign-in, API keys scoped to read or booking, encrypted calendar tokens, and an audit log that cannot be edited.
How an agent books
Three calls: find open times, hold one, confirm it with the client's name and email. A hold keeps the time for 5 minutes by default, up to 15.
GET /v1/tenants/{tenant}/availability
?service_id=…&staff_id=…&from=2026-11-10&to=2026-11-12
POST /v1/tenants/{tenant}/holds
{"service_id": "…", "staff_id": "…", "start": "2026-11-11T10:00:00-05:00"}
POST /v1/tenants/{tenant}/holds/{hold_id}/confirm
{"customer": {"name": "Ada Hale", "email": "ada@example.com"}}
If another caller takes the time first, the hold fails with
SLOT_UNAVAILABLE and up to three nearby open times, so the
agent can offer one. Holds and confirms take an idempotency key, so a
retry does not book twice.
The MCP server has the same steps as tools (find_slots,
hold_slot, confirm_booking). There is also an
OpenAPI document, a command-line tool, a TypeScript SDK, and signed
webhooks for created, confirmed, rescheduled and cancelled bookings.
Self-hosted or cloud
Self-hosted
Free and open source under the AGPL-3.0 license. One Docker image and Postgres, on your own server. You keep all the data.
Source code goes public at launch
Noonbell Cloud
The same software, hosted and run by us, so you do not need a server.
Coming soon. Prices to be announced.
Contact
For questions or early access, email privacy@noonbell.app.