<p> A unique and case-sensitive identifier that you provide to make sure the idempotency of the request, so multiple identical calls have the same effect as one single call. </p> <p> A client token is valid for 8 hours after the first request that uses it completes. After 8 hours, any request with the same client token is treated as a new request. If the request succeeds, any future uses of that token will be idempotent for another 8 hours. </p> <p> If you submit a request with the same client token but change one of the other parameters within the 8-hour idempotency window, Directory Service Data returns an <code>ConflictException</code>. </p> <note> <p> This parameter is optional when using the CLI or SDK. </p> </note>