> ## Documentation Index
> Fetch the complete documentation index at: https://docs.guile.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Idempotency Key Conflict

> The idempotency key was already used with different request details

## Cause

This idempotency key already identifies a different request body for the same
operation. Guile replays or rejects based on the first request; it does not run
your new parameters and does not create a second write.

## Fix

Retry the original request unchanged to get the first result, or use a new
idempotency key when you mean a different write.

## Retry safety

Safe to retry with a new idempotency key

## Raised by

These operations can return this problem:

* [Create an appointment](/api-reference/appointments/create-an-appointment)
* [Confirm a booking request](/api-reference/appointments/confirm-a-booking-request)
* [Decline a booking request](/api-reference/appointments/decline-a-booking-request)
* [Add a payment method](/api-reference/customers/add-a-payment-method)
* [Prepare a payment method](/api-reference/customers/prepare-a-payment-method)

## Example

```json theme={null}
{
  "type": "https://docs.guile.app/problems/idempotencyKeyConflict",
  "title": "Idempotency Key Conflict",
  "status": 409,
  "detail": "This idempotency key already identifies a different request body for the same operation. Guile replays or rejects based on the first request; it does not run your new parameters and does not create a second write."
}
```