SpacePay

Idempotency

Quick Answer

Idempotency in payment APIs means making the same request multiple times produces the same result, preventing duplicate charges from network retries or timeouts.

Full Definition

Idempotency in payment APIs means that making the same request multiple times produces the same result as making it once. It prevents duplicate charges caused by network retries, timeouts, or client-side errors. Payment APIs implement idempotency using unique keys — if a request with the same idempotency key is sent twice, the server returns the original response instead of processing a duplicate payment. This is critical for reliable payment integration.