macOS's Little-Known Command-Line Sandboxing Tool (2025)

Post by selridge » Sat, Feb 21, 2026, 5:04 PM UTC

comex wrote: post #33

kermatt wrote: post #8

Interesting config used a Scheme-like format. Any ideas on how that came to be?

Technically, it’s not just Scheme-like but literally a Scheme interpreter (TinyScheme). However, the Scheme isn’t being executed to make individual sandboxing decisions. It’s just executed once while parsing the config, to build up a binary sandbox definition which is what the kernel ultimately uses to make decisions (using a much more limited-purpose, non-Turing-complete execution engine).

Post by selridge » Sat, Feb 21, 2026, 5:06 PM UTC

mixtureoftakes wrote: post #42

what is with the ai written articles lately? and ai designed websites? who looks at it and goes "yes, ill upvote this. more people should see it."?

Post by theowaway213456 » Sat, Feb 21, 2026, 5:17 PM UTC

selridge wrote: post #24

MillionOClock wrote: post #20

Earlier quoted context omitted.

I wonder how many major applications and tools depend on sandbox-exec today despite that depreciation, IIRC I can think of the Codex CLI and Swift Package Manager.

Claude, Firefox, safari, chrome, etc etc etc etc Basically everyone who has to care about security on the Mac.

Post by simonw » Sat, Feb 21, 2026, 5:29 PM UTC

xyzzy_plugh wrote: post #11

It drives me nuts that sandbox-exec has "sandbox" in the name, since it's nothing like a real sandbox, and much closer to something like a high-level seccomp, and not much to do with "App Sandboxes" which is a distinct macOS feature. IMO a real sandbox let's a program act how it wishes without impacting anything outside the sandbox. In reality many of these tools just cause hard failures when attempting to cross the…

Post by js2 » Sat, Feb 21, 2026, 5:52 PM UTC

selridge wrote: post #38

cpach wrote: post #32

Earlier quoted context omitted.

Does anyone have any details regarding the deprecation? I wonder why Apple made this decision.

There’s not that much detail. A few comments in 2019 from a DTS person indicated that Apple didn’t really anticipate people shipping on this in volume. My guess is they want to dissuade people from using it. They can’t immediately just do away with it because a bunch of their first party apps use it (entitlements don’t cut it). It’s a weird space.