ExtensionKit is for the new facility to extend the UI. Non-UI extensions only need ExtensionFoundation. For example extensions on macOS, go to system preferen

ExtensionKit is for the new facility to extend the UI. Non-UI extensions only need ExtensionFoundation. For example extensions on macOS, go to system preferences and search for extensions. They're listed by affording context (e.g., Finder, Photos Editing). Mine include pdf conversion, cropping photos, etc. You can create your own via Automator. The docs imply that before Ventura (13.0), developers had to create a property list to declare NSExtension, but now you can do it in Swift. However, the TextTransformer sample has the usual melange of metadata, and there's no deployment information in the API documentation. Ideally, a simple swift script would be sufficient :) - https://github.com/insidegui/TextTransformer https://github.com/insidegui/TextTransformer