Payments

What is Idempotency?

Idempotency makes retries of one logical operation safe: repeating a request with the same key and same content returns its recorded outcome instead of performing the operation again. Keys must be scoped to the authenticated actor and endpoint, and reuse with different content should be rejected.

Idempotency does not make an operation correct or reversible. Systems need durable, atomic key claims, a documented retention window, and a policy for requests that are still processing. A timeout is an unknown outcome; clients should retry with the same key or query that operation.

Keys should contain no personal or payment data. Store a request fingerprint so the server can reject accidental reuse for another operation instead of returning an unrelated prior result.

Definitions are educational and general. Nothing here is financial, legal or tax advice, and regulatory descriptions summarise frameworks that change — check the current rules for your jurisdiction before relying on them.