App Extension Support

Manage the interaction between an app extension and its hosting app.


Extension Support

protocol NSExtensionRequestHandling

The interface an app extension uses to respond to a request from a host app.

class NSExtensionContext

The host app context from which an app extension is invoked.

Share Extensions

Supporting Suggestions in Your App’s Share Extension

Make your messaging app available for share sheet suggestions and use SiriKit intents to populate your app’s share extension.


class NSItemProvider

An item provider for conveying data or a file between processes during drag and drop or copy/paste activities, or from a host app to an app extension.

class NSExtensionItem

An immutable collection of values representing different aspects of an item for an extension to act upon.

Add Functionality to Finder with Action Extensions

Implement Action Extensions to provide quick access to commonly used features of your app.

Host App Interaction

class NSUserActivity

A representation of the state of your app at a moment in time.

protocol NSUserActivityDelegate

The interface through which a user activity instance notifies its delegate of updates.

See Also

App Support

Task Management

Manage your app’s work and how it interacts with system services like Handoff and Shortcuts.


Access assets and other data bundled with your app.


Design patterns for broadcasting information and for subscribing to broadcasts.

Errors and Exceptions

Respond to problem situations in your interactions with APIs, and fine-tune your app for better debugging.

Scripting Support

Allow users to control your app with AppleScript and other automation technologies, or run scripts from within your app.