A deprecated operation should provide a Sunset response header so consumers know when the operation will be removed and can plan their migration. Pairing deprecation with a Sunset header makes the deprecation policy explicit and machine-readable.
OpenAPI Operation Deprecated Sunset Info
Message: Deprecated operations SHOULD provide a Sunset response header.
Policies
Deprecation Sunset Headers
Every deprecated API operation must announce itself in-band using Deprecation and Sunset headers that tell consumers a change is coming and when it lands. I require that deprecation be signaled thr...
