I don't understand the use case. A command line client? A libray? In which language? With RHEL? In a rpm? Container? Via python pip?
Customer needs some command line S3 client to be able to interact with a Red Hat product such as Ceph RadosGW. OS - RHEL, added to RHEL/Ceph official repos.
s3cmd is in EPEL. This should provide the customer with a way to meet the "official repository" requirement.