Versions
Each API version is a date. Old versions stay served; X-API-Version picks one. An unpinned request gets the baseline, which never changes.
- What each version changed: Changelog.
- The reference for the current version is at /api; older versions have their own pages, linked from the changelog.
- The spec for any version:
https://sepetak.com/openapi.json?version=YYYY-MM-DD;info.x-versionslists them all.
A response shape only ever changes by cutting a new date. A field is never renamed or removed under a date that has shipped.