API Design · Middle · Question 40 of 75

Why should webhook handlers be idempotent?

1Webhooks are always delivered exactly once
2Idempotency makes webhooks faster
✓Correct answer: Providers retry on timeouts and errors, so the same event can arrive several times; handlers should dedupe by event ID

Explanation

Store processed event IDs, or make the effect naturally idempotent (e.g. set status rather than increment).

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