Idempotency Patterns

Spring Boot 3 baseline

The examples use Java 17 and Jakarta APIs supported by this Boot version. Keep dependencies managed by the project's Boot BOM.

Define the contract

Identify the authenticated tenant/principal, operation, idempotency key, canonical request hash, retention window and replayable result. Scope uniqueness by principal/tenant and operation; a raw client key must never allow reading another user's result. Authenticate and authorize before both initial execution and replay. Bound key length and stored response size. Document what same-key/different-payload and still-in-progress requests return.

Database-local effects