# performAction(identifier:onItemsWithIdentifiers:completionHandler:) Tells the File Provider extension to perform a custom action. ``` func performAction(identifier actionIdentifier: NSFileProviderExtensionActionIdentifier, onItemsWithIdentifiers itemIdentifiers: [NSFileProviderItemIdentifier], completionHandler: @escaping ((any Error)?) -> Void) -> Progress ``` ## Parameters `actionIdentifier` The identifier for the requested custom action from the extension’s `Info.plist` file. `itemIdentifiers` A list of item identifiers affected by the action. `completionHandler` A block that you call after completing the specified action. You pass the following parameters: - error: If an error occurs, this object contains information about the error; otherwise, it’s `nil`. ## Return Value An item that tracks your extension’s progress. ## Discussion Define the custom actions in the File Provider Extension’s `Info.plist` file, under the `NSExtensionFileProviderActions` key. The format of this key is identical to actions defined for a extension. For more information, see `Adding Actions to the Context Menu`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)