I got a kobo recently and was amazed to find you can sync it with calibre-web to basically run your own book store. Browse and download any books from your server. Pretty cool.

calibre is pretty great. I also have a kobo and its the reason I can load/convert a lot of what I read.

I need to figure this out for my wife, she got one recently and I've been dabbling with different services but haven't hooked the thing up to anything yet. Right now I've got Shelfmark and Booklore running which seem like they'll do the job just fine, but need to explore some more

There’s a fork that builds out additional features, mostly around library management: https://github.com/crocodilestick/Calibre-Web-Automated

I need to look into calibre-web more. I definitely tried it, but I remember it being awkward. Might give it another go to see