Does AWS S3 API copy-object copies the retentions and tagging also to another bucket?

Hello.

Tags will also be copied if you select "COPY" for "--tagging-directive" in the command options.
Object lock etc. can be configured using options such as "--object-lock-mode" and "--object-lock-retain-until-date".
https://awscli.amazonaws.com/v2/documentation/api/latest/reference/s3api/copy-object.html

When you perform copy operation on objects from one bucket to another: 1/ It will create a copy of object with updated settings and a new last-modified date. 2/ To have the source tags in place at destination, you need to pass --tagging-directive parameter in the Copy API request. Check AWS CLI document for more information: https://docs.aws.amazon.com/cli/latest/reference/s3api/copy-object.html