macOS File Provider API for Selective Sync?

Dropbox & Onedrive recently announced they will be updating their clients with new Selective Sync / “on demand files” functionality in macOS 12.3:

Those apps each rolled their own implementation up till now, but they used kernel extensions, which will be blocked in macOS 12.3, so they’re being forced to update their clients to use Apple’s File Provider APIs for that functionality.

Could Syncthing possibly support this functionality on Macs to provide a “native” implementation of Selective Sync / “on demand” files?

The Onedrive link has a few more interesting details as well:

The new Files On-Demand experience supports some existing features of APFS that were previously poorly supported by OneDrive. These include:

  • File tags
  • Last used date
  • File system flags
  • Extended attributes
  • Type and creator code
  • Symlinks

Extended attributes is a feature that’s also been sorely missing in Syncthing on Mac for a while - could this also be a way to get support for extended attributes into Syncthing?

Just a comment, but I used to have a lot of problems with Dropbox pushing Mac-style extended attributes to Windows devices. They were added to files as NTFS alternate data streams, and they were a major pain when using some of the built-in system tools (e.g. Windows backup, which was unable to deal with them and kept making new backup copies of the same files on every run).

Syncthing doesn’t have any on demand functionality.

Also, for what it’s worth, I’m a onedrive user and the new thing is … terrible. :grimacing: