Thank you very much for a great open source product!
After seeing your booth at the didacta 2026 and talking to one of the representatives who kindly asked me to post my bulk import solution, this is it: https://gist.github.com/hmt/fc84b4c6f5ee101c2ddd152696f05025
The Gist is in German and includes two Typescript classes that can be used to bulk import users into UCS via the UDM REST API.
I also included a script that shows how it can be done.
We are a school in NRW that’s why it also uses a Schild-DB connector to collect user information. This is not a requirement. The users can be created in any way and be sent to the API. It allows creating, deleting and modifying users. Modifying is not fully tested and needs some extra work. The whole script is not really finished but it does the job for me and is used multiple times a week because we have a lot new users.
I highly suspect that you will have to modify a lot to make this script work for you, so go ahead and fork it 