Rate limiting

Responses may include RateLimit-Limit, RateLimit-Remaining, and RateLimit-Reset. A 429 problem includes Retry-After. Wait at least that long, add random jitter, then retry reads or idempotent requests. Preserve the idempotency key and payload.

Do not blindly retry validation, scope, state, version, or permanent-deletion failures. Repeated authentication or destructive probes may be throttled more aggressively.