Developer ID Application is the certificate type Mac developers use when they distribute apps outside the Mac App Store. It is a separate signing identity from the Apple Distribution certificate used for the App Store, and it has very different rules: it is issued only to Apple Developer Program teams (not personal teams), and it is what Gatekeeper checks before letting a downloaded app launch on a user's Mac.
Where you see it
- Apps shipped from your own website, GitHub Releases, Homebrew, Sparkle auto-updates, or any direct download.
- Internal Mac tools distributed inside an organization without using MDM-managed enterprise distribution.
- Notarytool submissions: every notarized Mac app must be signed by a Developer ID Application certificate first.
Pairs with two other things
- Developer ID Installer
- A separate Apple-issued certificate that signs the .pkg installer wrapping a Developer ID Application-signed binary. Required if you distribute as a .pkg.
- Notarization
- After signing with Developer ID Application, you submit the build to Apple's notary service. Notarization is what removes the 'unidentified developer' warning and lets Gatekeeper green-light the app.