[Moru]

Do you want to sync the whole library with the iphone or just search and download from the iphone? Calibre can be used to just transfer a few books by installing the calibre app on the phone and select books on the computer to transfer. There are also solutions for searching and downloading books from the phone but I haven't tried them much, found it much easier to use the computer to do that.

I can't fit my library on the phone so haven't even thought of syncing the whole thing.

[NonNefarious]

I want to sync the whole thing. Apple Books ineptly forces you to manually copy all of the books themselves to each device, but then syncs collections that you've set up to organize them.

[Moru]

Have you tried Resilio Sync?[0] I'm using it on Android but seems to exist for iOS [1] too. I'm not syncing the library though, might want to make sure you only run the sync when Calibre isn't running to prevent data loss.

[0] https://www.resilio.com/individuals/

[1] https://apps.apple.com/us/app/id1126282325

[mattkevan]

No it doesn’t. If you use Books with iCloud any book you add on any device will be automatically synced with the others. Works really well.

[skydhash]

It does, but there is an ongoing bug [0] - which I suffer myself - that is always removing the local version of the book. I grew tired of always having to redownload books after a few days.

[0] https://apple.stackexchange.com/questions/344271/books-autom...

[NonNefarious]

I wish that were true; but I just checked the computer I'm typing this on, and it's missing books from my other one (which is logged in with the same iCloud account).

I have "download new purchases automatically" on.