# 24008: Idempotency conflict

Log Type: TWILIO

Log Level: ERROR

## Description

The `Idempotency-Key` header value was previously used with a different request payload. The Audiences service stores a hash of the original request associated with each idempotency key. When a subsequent request uses the same key but a different payload, this error is returned to prevent unintended duplicate operations.

### Possible causes

* You reused an `Idempotency-Key` value from a previous request but changed the request body, query parameters, or other payload elements.
* Your application generates idempotency keys that are not sufficiently unique, causing collisions between unrelated requests.
* A retry mechanism resubmitted a request with the same idempotency key after the original request payload was modified between attempts.

### Possible solutions

* Generate a new unique `Idempotency-Key` value for each distinct operation. Use a UUID or another high-entropy identifier that is unique per logical operation.
* If you are retrying a failed request, ensure the request payload is byte-for-byte identical to the original attempt. Do not modify the body, query parameters, or headers (other than `Idempotency-Key`) between retries.
* If you intentionally want to perform a different operation, use a new idempotency key. Each unique operation must have its own key.
* Idempotency keys expire after a retention period. If you need to retry an operation long after the original attempt, a new key may be required.

#### Additional resources

* [Audiences API reference](/docs/segment/audiences/api)