macOS: “damaged and can't be opened”

Why this happens

Gatekeeper checks an app's signature and notarization status. Beta builds are not yet signed or notarized, so they're treated as untrusted — and surfaced with the misleading word “damaged”.

You'll see the same message on many unsigned open-source apps. It isn't specific to this one.

Using the command

Move the app to Applications first, then run: xattr -cr "/Applications/BestCodex.app".

-c clears extended attributes and -r recurses through everything inside the bundle. The path has to match the actual app name.

Don't run it across your whole Applications folder, and you don't need sudo.

To skip this step entirely, install with curl -fsSL https://bestcodex.app/install.sh | sh: the script verifies the SHA256, installs into Applications, and clears the quarantine attribute for you.

Still won't open

Control-click the icon, choose Open, then confirm Open again in the dialog.

If the error mentions permissions or architecture instead, check that you downloaded the build for your chip — Apple silicon and Intel are separate installers.