Bounded requests
Search and intelligence lists accept limit=1–100 and offset=0–1000000. Compare two to four distinct products. History ranges are 7d, 30d, 90d and 1y. Snapshot requests are limited to 1 MiB and 1,000 entries per collection. Monetary inputs use a single declared currency and consistent tax basis.
Safe retries
Retain Idempotency-Key for mutating POST and PUT retries for 24 hours. Read-only products/resolve and offers/batch POSTs need no replay key and each successful live retry is metered. Reusing a mutation key with different content returns 409. PATCH requires expected_revision from the latest watch. Correct 400/401/403/404/409 requests; retry transient 429/5xx responses with bounded backoff and Retry-After when provided. Failed API reads release their usage reservation.