You can still use FSEvents/kqueue and Finder APIs to implement a file synchronization daemon. But Dropbox hasn't done that for a while. A few years ago they mov

You can still use FSEvents/kqueue and Finder APIs to implement a file synchronization daemon. But Dropbox hasn't done that for a while. A few years ago they moved to a kernel extension that exposes your Dropbox as virtual files that are downloaded on demand when you open them. They called this Project Infinite: https://blog.dropbox.com/topics/company/announcing-project-infinite https://blog.dropbox.com/topics/company/announcing-project-i...