Hi, I'm working with the new FSKit framework and have successfully implemented a custom file system using FSUnaryFileSystem. Mounting the file system via Terminal works perfectly — I can create, delete, and browse files and directories as expected. Since /Volumes is protected on modern macOS systems, I cannot mount my file system there directly. Instead, I mount it into a different writable directory (e.g., /tmp/MyFS) and then create a symbolic link to it in a user-visible location such as ~/Downloads/MyFS. Finder does see the symlink and displays it with a "Volume" icon, but clicking it results in an error — it cannot be opened. It seems like Finder does not treat the symlinked mount as a fully functional volume. Is there a proper way to register or announce a FSKit-mounted file system so that Finder lists it as a real volume and allows access to it? Are there additional steps (APIs, notifications, entitlements, or Info.plist keys) required to integrate with Finder? Any insight would be greatly appreciated. Thanks!

I have my both app and fskit sandboxed <key>com.apple.security.app-sandbox</key> <true/> Which means that I can read files only in app container. First, is sandboxing required for fskit modules? Second, there are docs which implies that it's possible to explicitly allow fskit module to access external files, by passing their paths to mount params. https://developer.apple.com/documentation/fskit/fstaskoptions/url(foroption:) and also options: Options to apply to the activation. These can include security-scoped file paths. There are no defined options currently. I've tried this, but haven't success. My Info.plist is <key>FSActivateOptionSyntax</key> <dict> <key>shortOptions</key> <string>g:m:</string> <key>pathOptions</key> <dict> <key>m</key> <string>file</string> <key>g</key> <string>directory</string> </dict> </dict> I'm mounting with mount -F -t MyFS -o -m=./build.sh,-g=./ /dev/disk5 /tmp/TestVol Getting them via options.url(forOption: "m"), options.url(forOption: "g") Both nulls. I also see that options are presented in options.taskOptions But they are not expanded to absolute pathes or urls, which makes me think that pathOptions declaration is incorrect. Docs says This dictionary uses the command option name as a key, and each entry has a value indicating what kind of entry to create. What entry kind means in this context? Can you send example of correct pathOptions?

macos 15.4 beta claims to support FSKit. Is there an FSKit sample available? I don't see anything useful in the published docs.

Looking for any more documentation on FSKit - https://developer.apple.com/documentation/fskit?language=objc I don't see any examples or sessions on it, but it looks fascinating. Attempted to try to put something together and immediately ran into failed at lookup with error 159 - Sandbox restriction

Capability to read and write ofd HFS disks on Mac has been removed since a long time. Capability to simply read was also removed since Catalina I think. That is surprising and sometimes frustrating. I still use a 90's MacBook for a few tasks and need from time to time to transfer files to newer Mac or read some old files stored on 3.5" disks. Solution I use is to read the disk on an old Mac with MacOS 10.6 (I'm lucky enough to have kept one) and transfer to USB stick or airdrop… As there is no USB port on the Macbook of course (and I have no more a working 56k modem to transfer by mail), only option if not 3,5" disk is using PCMCIA port on the MacBook for writing to an SD Card to be read in Mac Sonoma. But reading directly 3.5" disk would be great. Hence my questions for the forum: how hard would it be to write such a driver for READING only HFS on Mac Sonoma? There are some software like FuseHFS. Did anyone experience it ? Did anyone have a look at the source code (said to be open source). does anyone know why Apple removed such capability (I thought it was a tiny piece of code compared to the GB of present MacOS)? Thanks for any insights on the matter.