An *idempotent *operation is one where a request can be retransmitted or retried with no additional side effects, a property that is very beneficial in distributed systems.
From an API standpoint, idempotency means clients can make the same call repeatedly and produce the same result. https://blog.bytebytego.com/p/how-to-avoid-double-payment
idempotent APIs are APIs where any write operations can have effect only once for a given set of parameters. https://ieftimov.com/posts/understand-how-why-add-idempotent-requests-api/