Payroll API

Idempotency

The Payroll API has no side effects: every endpoint is a pure calculation over the request body you send, or a file generated from data you provide. Nothing is stored, nothing is charged by the call itself, and no resource is created that a duplicate request could clash with. That means every request — including every write — is naturally safe to retry with the same body, as many times as you like, with no Idempotency-Key header and no special handling on your side.

This is different from the e-Faktura API, where issuing a document is a real, UJP-facing side effect and does require one.