DEV Building on it

Two lines, or the whole diary.

Most people want the booking page on a site they already have, and that is a copy and a paste. If you are building something on top, the same booking pipeline is available over HTTP with keys, idempotency and signed webhooks.

ENDPOINTS: 15
WEBHOOK TOPICS: 6
AUTH: Bearer key
SPEC: OpenAPI 3.1

MINUTES

Embed the booking page

Two lines of HTML on any site — WordPress, Squarespace, Webflow, a hand-written page. The widget sizes itself and needs no build step.

Embed guide REST

The /v1 API

15 endpoints over bearer keys: read the catalog, ask what is free, hold a slot, take the booking. Every write goes through the same pipeline the booking page uses.

API reference PUSH

Webhooks

6 signed topics delivered to your endpoint, with retries and automatic disabling when a destination stays broken.

Topics and signing

RULES What holds on the wire

Four things you can rely on.

One pipeline, whichever door: A booking made through the API takes the same advisory lock, the same in-transaction re-check and the same exclusion constraint as one made on the booking page. There is no faster path that skips a rule.
Money is integers: Every amount on the wire is a whole number of minor units — pence, cents — with the currency beside it. No decimal strings, no floats, and zero-decimal currencies handled in both directions.
Time is UTC, with a zone: Instants are RFC 3339 in UTC. The tenant’s IANA zone comes back from /v1/ping so you can render them where the customer is, rather than guessing from the server.
Retries cannot double-book: Writes take an idempotency key. Repeat a request and you get the original answer back rather than a second appointment — which matters most on the request you are least sure landed.

MAP What is there

The surface, in groups.

Full reference

Catalog

4 endpoints

What is bookable: services with their durations and prices, the people who perform them, and where.

Availability

1 endpoint

The times a booking would actually be accepted. Computed from opening hours, the person, the service, holidays, blocked time and what is already booked — so a slot you are offered is one you can take.

Reservations

3 endpoints

Hold a slot briefly while a customer finishes deciding. A reservation is not a booking and expires on its own.

Bookings

5 endpoints

Create, read, reschedule and cancel appointments. Every write goes through the same pipeline the booking page uses, so nothing reached this way behaves differently.