The new tap
Cirrus Labs announced on April 7, 2026 that it's joining OpenAI's Agent Infrastructure team. That's why the Homebrew formula moved from cirruslabs/cli to openai/tools.
The new install path adds the OpenAI tap and trusts both formulae:
brew tap openai/tools
brew trust --formula openai/tools/tart
brew trust --formula openai/tools/softnet
brew install openai/tools/tart
Wait, it doesn't work
That installed Tart 2.33.0 and OpenAI Softnet 0.20.1 in my test on macOS 27.0 build 26A5378n. Both tart --version and tart --help exited 137. Depending on how you launched it, you'd just see zsh: killed tart.
The problem
macOS's security logs had the answer. Gatekeeper flagged Tart 2.33.0 as source=Unnotarized Developer ID. AMFI (AppleMobileFileIntegrityError) reported an unsatisfied com.apple.vm.networking entitlement — no matching profile found. The signature checks out, but the notarisation and networking-entitlement profile don't, so macOS kills Tart before it can run.
So I had to rollback
Roll back to the Cirrus tap:
brew uninstall openai/tools/tart openai/tools/softnet
brew tap cirruslabs/cli
brew trust --formula cirruslabs/cli/tart
brew trust --formula cirruslabs/cli/softnet
brew install cirruslabs/cli/tart
tart --version
tart --helpThis installed the older 2.32.1 no issues running tart and Gatekeeper reported source=Notarized Developer ID.
Hold the openai/tools/tart upgrade on your mac for now. Stay on cirruslabs/cli/tart and track the fix at openai/homebrew-tools issue #27.