What is the App Sandbox on Mac?
The App Sandbox is a macOS feature that restricts an app’s access to system resources and user data. Apple’s stated aim is to contain the damage if an app becomes compromised. Apple says it limits an app’s access to the resources it requests through entitlements.
Why it matters
Apple says that to distribute a macOS app through the Mac App Store, you must enable the App Sandbox capability. Apps distributed outside the store, as NotchStar is, are not required to by that rule.
NotchStar and the sandbox
NotchStar’s entitlements file does not include the App Sandbox key, so it is not sandboxed. It is signed with a Developer ID, notarized by Apple and uses the hardened runtime, and it asks for permission to reach the camera, calendars and Apple Events. Its Disk tool never deletes anything: everything goes to the Trash, only inside the home folder and app bundles in /Applications, and scans start only when you press a button.
Not the same thing
The sandbox and the hardened runtime are separate. The sandbox limits resources an app can reach. The hardened runtime limits how code behaves inside the app.
Related
Read about entitlements, the Disk tool and is NotchStar safe.