A lot of the UI scripting on macOS is accomplished via accessibility APIs. If you’re interested, check out Accessibility Inspector[0], which ships with Xcode. You can inspect macOS applications in a similar, albeit much more limited way to a web browser’s interactive inspect element function.

You can also accomplish UI scripting via C/ObjC/Swift using the Application Services framework [1].

[0] https://developer.apple.com/library/archive/documentation/Ac... [1] https://developer.apple.com/documentation/applicationservice...