[aerique]

I use rMAPI to push and pull stuff from the machine. Not sure if it works for the rm2 as well.

Also, it requires storing your stuff on reMarkable's servers ('cloud').

https://github.com/juruen/rmapi

[abawany]

I love rmapi and use it often with my rM2.

[sabauma]

I find rmapi + fzf to be the easiest way to send ebooks in my Calibre library to my rM2.

Its probably possible to create a Calibre addon to do this, but its already makes syncing pretty easy.