Deprecation policy

Muster's API discipline requirements (docs/ROADMAP.md Phase 7) codify how Safe Signals removes capabilities from the public API.

The five rules

1. Additive changes never require notice. Adding a method or field is always safe. Old clients ignore new fields.
2. Removal requires a v2 proto package. Wire-format breaks never happen within v1. When a change is truly breaking, Safe Signals ships muster.api.v2 that coexists with v1 during the deprecation window.
3. 6-month advance notice. Before removing anything, Safe Signals notifies all integrators via:
   • The API changelog at changelog.md.
   • Email to the contact address you provided at integration registration.
   • HTTP response headers on the affected endpoints (Deprecation + Sunset).
4. 12-month minimum overlap. Once notice is given, the deprecated endpoint stays live for at least 12 months before removal. During that window it responds normally but with the Deprecation header set.
5. Removal is coordinated. Removal date coincides with a new v1.<n> schema-version release, not a silent server change.

HTTP header signaling

Deprecated endpoints respond with:

HTTP/1.1 200 OK
              Deprecation: version="1.0"
              Sunset: Wed, 06 Jul 2027 00:00:00 GMT
              Link: <https://docs.safesignals.io/api/changelog>; rel="deprecation"
              

Non-deprecated endpoints omit these headers.

What deprecation does NOT mean

• Silent behavior changes. A deprecated endpoint's response shape stays stable.
• Rate-limit changes. Deprecation status doesn't affect rate-limit accounting.
• Auth changes. Auth requirements remain the same.

Deprecations in v1 today

None. v1 is the inaugural version; every method + field is current.