Verified against Semitexa Ultimate 2026.09.19.1020

Active Version

The active version should feel intentionally boring: same response shape, stable metadata, and no sunset chatter for clients to parse around.

How it works

#[ApiVersion] on the Payload DTO declares the version string and lifecycle state. When the state is active, the framework emits X-Api-Version on every response without additional lifecycle headers. No Deprecation header, no Sunset header — just a stable version token that makes the serving contract traceable in logs and observability tooling.

Why this matters

Clients get stable version traceability without deprecation churn. Migration pressure should disappear once a client is on the supported path. The JSON contract is identical in shape to older versions, but the lifecycle signal is clean — which is the expected steady state for any API route that is not under retirement pressure.