What steps do I need to perform to create an App Clip that is launched when a web site is visited? I already have written the main app in SwiftUI.

To create an App Clip that is launched when a website is visited, you can follow these general steps:

1. Create an App Clip Target: In Xcode, add a new App Clip target to your existing app project. This will allow you to create a lightweight version of your app that can be launched quickly.

2. Configure the App Clip: Set up the App Clip's Info.plist file with the necessary configurations, such as the URL patterns that will trigger the App Clip. This involves specifying the NSUserActivityTypes and NSUserActivity for the URL handling.

3. Design the App Clip Experience: Use SwiftUI to design the user interface for your App Clip. SwiftUI is a great choice for building the UI because it allows for a declarative and compositional approach, which is efficient for creating engaging user experiences.

4. Implement App Clip Code: Write the code necessary for the App Clip to perform its intended function. This might involve using the App Intents framework to define specific actions or shortcuts that the App Clip can perform.

5. Test the App Clip: Use Xcode's testing tools to ensure that the App Clip launches correctly when the specified URL is visited and that it performs its functions as expected.

6. Deploy and Monitor: Once your App Clip is ready, deploy it alongside your main app. Monitor its usage and performance to ensure it meets user needs.

For more detailed guidance, you might want to refer to the session Bring your app’s core features to users with App Intents (08:06) which covers building code with the App Intents framework, which can be useful for creating app shortcuts and actions that might be relevant for your App Clip.