---
title: configuration
framework: extensionfoundation
role: symbol
role_heading: Instance Property
path: extensionfoundation/appextension/configuration-swift.property
---

# configuration

The configuration details for this app extension.

## Declaration

```swift
@MainActor @preconcurrency var configuration: Self.Configuration { get }
```

## Discussion

Discussion Implement this property in your custom type and use it to store the configuration details for your app extension. As part of the configuration, provide code to establish an XPC connection back to the host app. If your app extension sends only data to the host app, and doesn’t provide a UI, use this property to store a type that implements the AppExtensionConfiguration protocol. If your extension provides UI elements for the host app to display, instead store an instance of the AppExtensionSceneConfiguration type.

## See Also

### Configuring the app extension

- [Configuration](extensionfoundation/appextension/configuration-swift.associatedtype.md)