Use whenever the same request or message could be processed twice (at-least-once queues, retries, webhook redelivery, double clicks, mobile retries) and duplicates must have no extra effect. Tests idempotency keys, delivery semantics, fingerprint dedup and the idempotency window.
The canonical home for this skill is testland/idempotency-test-author
Scanned
testland/qa
aa16752
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