# Idempotency Key

> A technique for tagging each request with a unique key, so a repeated request is recognized and applied once.

Record: `lexicon:idempotency-key`
Kind: technique
Layer: [Correctness Core](https://banes-lab.com/records/layer/correctness-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-idempotency-key

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Translate Errors at the Boundary](https://banes-lab.com/records/lexicon/translate-errors-at-the-boundary.md) and before [Bounded Retry](https://banes-lab.com/records/lexicon/bounded-retry.md).

## Category

- [Error Handling / Resilience](https://banes-lab.com/records/lexicon-category/error-handling-resilience.md)

## Refactors

- [Retry Storm](https://banes-lab.com/records/architecture/retry-storm.md)
- [Retry Pattern](https://banes-lab.com/records/architecture/retry-pattern.md)
- [Idempotency](https://banes-lab.com/records/architecture/idempotency.md)

## Linked from

- [Anti-patterns](https://banes-lab.com/ontology/principles/architecture-category-anti-patterns.md)
- [Error Handling / Resilience](https://banes-lab.com/ontology/principles/architecture-category-error-handling-resilience.md)
- [Transactions / State / Concurrency](https://banes-lab.com/ontology/principles/architecture-category-transactions-state-concurrency.md)