Definition
Designing an operation so applying it twice has the same effect as once.
How it works
An idempotency key lets retries be safe (no double-charge). At-least-once delivery + idempotency = exactly-once effect.
Learn more on SystemLore
Common questions
What is Idempotency?
Designing an operation so applying it twice has the same effect as once.
How does Idempotency work?
An idempotency key lets retries be safe (no double-charge). At-least-once delivery + idempotency = exactly-once effect.
What is Idempotency used for in system design?
An idempotency key lets retries be safe (no double-charge). At-least-once delivery + idempotency = exactly-once effect.
Part of Glossary on SystemLore — system design explained with 148 deep topics, interactive diagrams, and a build-it-yourself game. Build this one →