Idempotency

Make generation POSTs safe to retry with an Idempotency-Key header.

Pass Idempotency-Key: <your-random-key> on any POST /v1/generations/... request to make the call safe to retry. The first call creates the job; subsequent calls with the same key (within 24 h) return the original response without creating a duplicate. Different request body + same key → 409 idempotency_key_conflict.

Recommended: a UUID per logical request from your application.