idempotent_replay

What happened

This request was already processed. Nothing was changed a second time.

Technical background

IdempotentReplayError means the caller sent a write with an idempotencyKey it had already used. The partial unique index on metadata.idempotencyKey in the event store caught the duplicate. details carries the idempotencyKey.

Do not retry: the earlier attempt already succeeded and this one is a no-op replay. Use a new key only for a genuinely new operation. It differs from unique_violation and version_conflict, which are real conflicts.