# idempotency

CEFR C2 · Noun

Source: https://englishreference.com/word/idempotency
Updated: 2026-07-22

## Definition

a property of an action where doing it many times has the same result as doing it just once. For example, pressing a 'stop' button twice doesn't stop a machine more than pressing it once.

For teachers: the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application.

## Examples

- The system design ensures idempotency for all payment requests.
- In API design, idempotency is crucial because it allows a client to safely retry a request if the network connection fails.
- Ensuring the idempotency of database transactions prevents the accidental duplication of records during high-latency periods when users might refresh their browsers repeatedly.

## Usage notes

- Primarily used in technical contexts such as mathematics, logic, and RESTful API development.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.