API versioning and deprecation policy

This policy applies to the public Apartment Fax REST API documented in the OpenAPI specification. The current supported major version is /v1. No v1 retirement is scheduled.

Versioning guarantee

Backward-compatible additions remain in /v1. A change that removes or renames a field or endpoint, makes an optional input required, or otherwise breaks existing clients will use a new /vN URL prefix.

Deprecation notice

Apartment Fax will publish at least 180 days of notice before retiring a supported major API version. The notice will identify the replacement version, migration path, deprecation date, and sunset date on this page, in the OpenAPI specification, and in llms.txt.

Response headers

Deprecation: Present only after a version is formally deprecated. Its value is the RFC 9745 Structured Field date when deprecation was announced.
Sunset: Present only after retirement is scheduled. Its RFC 8594 HTTP-date states when the deprecated version will stop responding.

Because v1 is active and has no scheduled retirement, its live responses do not currently include either lifecycle header. Clients can rely on the notice period and begin migration when those headers appear.

Last updated: August 30, 2026.