I’m a NixOS convert too. I actually still run everything in docker but the idea of not having to remeber or document how I set everything up was too appealing…a year later and my desktop and laptop are now on nix too

You are on the sever page. Soumds like you’re actually looking for clients here:

https://jellyfin.org/downloads/clients

Syncing support is a core feature of immich. The app is top notch from my experience with it.

Would highly reccomend https://immich.app/ too. It’s the solution I’ve finally landed on after trying out most of the options out there.