An idempotency key is a client-provided unique value used by an API to recognize repeated requests that should produce only one effective outcome. It matters because retries, network failures, and replay conditions can otherwise cause duplicate actions with security and business impact.
What is Idempotency Key?
Idempotency keys are common in payment APIs, order creation, and other state-changing operations where the same request may be resent. They help servers distinguish legitimate retry behavior from unwanted duplicate execution.
What Idempotency Key Commonly Supports
Common uses include safe retries, replay resistance, transaction integrity, and resilient API design.
Idempotency Key vs. Duplicate Action Execution
An idempotency key helps ensure a repeated request maps to one logical action. Without it, repeated requests may create duplicate effects.
Frequently Asked Questions
Why are idempotency keys useful?
Because they make APIs more robust against retries and some replay-style errors without breaking reliability.
Do idempotency keys replace authorization?
No. They solve duplicate execution problems, not identity or permission checks.
