AWS recently added support for this: https://aws.amazon.com/about-aws/whats-new/2024/11/amazon-s3-functionality-conditional-writes/ Azure already supported a similar feature: https://learn.microsoft.com/en-us/azure/storage/blobs/concurrency-manage As does GCS: https://cloud.google.com/storage/docs/request-preconditions#precondition_criteria This will require jclouds support in PutOptions.