ADR 0006: No API versions

Status: accepted (2026-09-09)

Schemas evolve additively. rayfold check --against rayfold.lock.json rejects breaking changes. Removal requires @deprecated(sunset:) and a date in the past. Field usage is recorded per client, so removal is a fact. Ordinals in the lockfile are reserved for a future compact-struct encoding; RB does not use them today, and rayfold check only guards them against changing.