Retries are normal in distributed systems. A caller may time out after the server commits a decision, a queue may redeliver a message, or a webhook sender may repeat an event. A decision API that treats every request as new can double-charge, duplicate actions, or record conflicting outcomes.
Source: [Dev.to](https://dev.to/seo_optimization_591fad6c/designing-idempotent-decision-endpoints-that-survive-real-retries-6c1)