# openTabs A set of open tabs in all open windows that are exposed to this extension. ``` var openTabs: Set { get } ``` ## Discussion Provides a set of tabs in all open windows that are visible to the extension, as updated by the [`didOpenTab(_:)`](/documentation/WebKit/WKWebExtensionContext/didOpenTab(_:)) and [`didCloseTab:windowIsClosing:`](/documentation/WebKit/WKWebExtensionContext/didCloseTab:windowIsClosing:) methods. Initially populated by the tabs in the windows returned by the extension controller delegate method [`webExtensionController(_:openWindowsFor:)`](/documentation/WebKit/WKWebExtensionControllerDelegate/webExtensionController(_:openWindowsFor:)). ## See Also [`didOpenTab(_:)`](/documentation/WebKit/WKWebExtensionContext/didOpenTab(_:)) Called by the app when a new tab is opened to fire appropriate events with only this extension. [`didCloseTab:windowIsClosing:`](/documentation/WebKit/WKWebExtensionContext/didCloseTab:windowIsClosing:) Called by the app when a tab is closed to fire appropriate events with only this extension. --- 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)