Its been forever since I set it up but you can also sync via ssh, so, wirelessly recursively sync a directory. I think I loaded my books over USB, then synced

Its been forever since I set it up but you can also sync via ssh, so, wirelessly recursively sync a directory. I think I loaded my books over USB, then synced daily news and additional books via rsync. Some of the content was auto generated and dumped into the dir like some auto fetch and email subscriptions, some was manual like copying in a new book after purchase. But its not a very complicated problem, calibre just does a ton of other stuff too outside of copying books into a specific folder structure.