RFC 9745 defines the Deprecation HTTP response header field, whose value is a date when a resource will be or was deprecated, and the deprecation link relation type pointing to deprecation policy or migration guidance. Published March 2025 on the Standards Track.
Deprecation HTTP Response Header Field (RFC 9745)
RFC 9745, by Sanjay Dalal and Erik Wilde, gives a resource a way to say it is deprecated: a Deprecation header whose value is a date (past or future), and a deprecation link relation pointing at documentation of the deprecation policy or migration path. The signal is a hint and does not change how the resource behaves. Used with the Sunset header (RFC 8594), the sunset date must not be earlier than the deprecation date.
Business layer
The API Commons deprecation-policy schema records whether a provider emits the Deprecation header, next to notice periods and announcement channels. See The Technical Side Translated. The Business Side Did Not.
Industry: api-specification
