Nexus 3 offers some API (https://help.sonatype.com/repomanager3/rest-and-integration-api) but no endpoint seems to exist to get the current user information (name, email, ...)
I don't have an admin access, so I can't use /security/users endpoint
Is there some API that is not documented?
It appears that nexus 3 and an (undocumented?) internal API. The following endpoint can be used to retrieve the current user:
/internal/ui/user