API

Versioning

How circuly API versions work and which one to use.

Every request path starts with an API version:

GET https://api.circuly.io/2026-04/...

Available versions

Version	Status	Supported until	Notes
`2026-04`	Current	1 Apr 2027	Initial stable release. `v1` is an alias for it.
`unstable`	Unstable	—	Latest unreleased changes; may change any time.

Versions are dated (YYYY-MM) and released quarterly. Each is supported for 12 months, with a 9-month overlap so you have time to migrate.

Every versioned response tells you what you got:

X-Api-Version: the version that handled the request.
Sunset: when that version stops being supported.
Deprecation and X-Api-Deprecation-Warning: sent when the version is deprecated.
X-Api-Version-Warning: sent when a sunset or unknown version was requested and the API fell forward to a supported one.

Pick a version in the API reference to see its endpoints and changes.