Versioning

The API uses a stable /v1 path together with date-based versioning carried in a request header. This lets us evolve response shapes over time without breaking existing integrations.

The `Service-Version` header

Versions are date strings, for example 2026-06-27. Send one with any request:

curl https://api.useservice.app/v1/reservations \
  -H "Authorization: Bearer $SERVICE_API_KEY" \
  -H "Service-Version: 2026-06-27"

How the version is resolved

Pinned per key. Each API key is pinned to a version when it is created. If you send no Service-Version header, that pinned version is used. This means your integration keeps working unchanged even as new versions ship.
Per-request override. If you send a Service-Version header, it overrides the key’s pinned version for that single request — useful for testing a newer version before adopting it.

Echoed in responses

Every response echoes the version that served it, so you can confirm exactly which behaviour you got:

HTTP/1.1 200 OK
Service-Version: 2026-06-27
Content-Type: application/json

Current version

There is currently a single version: 2026-06-27. When new versions are introduced, this page will list them along with the changes each one makes. Webhook endpoints are likewise pinned to a version at creation, so the payloads you receive stay consistent. See Webhooks.

Changes to `2026-06-27`

These changes were made to 2026-06-27 in place, without a new version date.

September 2026 — guest last_name can be null. Like first_name, the last_name of a guest is now nullable: in the guest object, in an expanded guest on a reservation, and in guest.* webhook payloads. The key is always present. See Guest events for the rule on names.
September 2026 — reservations carry company. The reservation object, in the API and in reservation.* webhook payloads, always has a company key: the company the booking is made for, or null. See Reservation events.
September 2026 — previous_attributes can contain company. A reservation.updated event whose company changed carries the previous company in previous_attributes.