samber/developer-platform-skills

api-idempotency-retry

Design idempotency-key support and client retry guidance for a public API so integrators retry safely - key derivation and per-caller scoping, storage TTL and replay windows, atomic claim mechanisms (DB unique constraint, SERIALIZABLE row lock, conditional writes), payload-mismatch rejection, in-flight duplicate handling, exponential backoff with jitter, retry budgets, timeout propagation, and SDK retry defaults. Use whenever the user mentions an Idempotency-Key header, duplicate or double-submitted requests, safe POST retries, backoff, or jitter - even if they never say "idempotency". Do NOT use for what the error response signals (samber/developer-platform-skills@api-error-design) or webhook delivery retries (samber/developer-platform-skills@webhook-platform-design).