| 409 | A transaction with the supplied idempotency-key is already in progress | This error occurs when the idempotency key supplied with a request matches the idempotency key supplied with a previous transaction but a final result has not yet been recorded for the original transaction. This "in progress" response protects against duplicate request submissions and will be returned until the original request is completed and its final result is recorded. Any subsequent requests with the same idempotency key will return the original transaction's final result. |
