Idempotency

A practical example

Example: a payment webhook fires twice for the same transaction due to a network timeout; an idempotent handler processes the first attempt and discards the second, so the customer receives one receipt.

What to evaluate before investing

• Ask whether the API accepts idempotency keys and how long the platform remembers them.
• Confirm how sync jobs deduplicate records: which unique field is used and can you choose it?
• Test retry behavior in a sandbox: trigger a deliberate failure and verify no duplicates result.

Limitations and tradeoffs

Protection depends on key scope, retention and concurrency handling. Reusing a key for a different action can suppress valid work, while retrying after its retention window can repeat an effect. Test both cases.