Idempotency-Key header: a repeat with
the same key returns the original job instead of starting (and charging for) a new one.
- Use a unique key per logical operation (a UUID works well). Max 255 characters.
- Keys are scoped to your API key and retained ~24h.
- A retry with the same key returns the same job (
202) - no second generation, no second charge. - A different key always creates a new job.
POST /images/generate, /images/edit, /images/resize,
/images/upscale, and /styles/extract.
Idempotency protects sequential retries (timeout → retry). If you fire two identical requests truly
in parallel before either is recorded, you may still get two jobs - generate the key once and reuse
it on retries.

