# AppExtensionSceneBuilder A custom parameter attribute that constructs extension scenes from closures. ``` @MainActor @preconcurrency @resultBuilder struct AppExtensionSceneBuilder ``` ## Topics ### Building the scene’s content [`static func buildBlock(Content) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:)) Passes through a single extension scene unmodified. [`static func buildBlock(C0, C1) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:)) Builds an extension scene by combining two scenes. [`static func buildBlock(C0, C1, C2) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:)) Builds an extension scene by combining three scenes. [`static func buildBlock(C0, C1, C2, C3) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:)) Builds an extension scene by combining four scenes. [`static func buildBlock(C0, C1, C2, C3, C4) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:)) Builds an extension scene by combining five scenes. [`static func buildBlock(C0, C1, C2, C3, C4, C5) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:_:)) Builds an extension scene by combining six scenes. [`static func buildBlock(C0, C1, C2, C3, C4, C5, C6) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:_:_:)) Builds an extension scene by combining seven scenes. [`static func buildBlock(C0, C1, C2, C3, C4, C5, C6, C7) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:_:_:_:)) Builds an extension scene by combining eight scenes. [`static func buildBlock(C0, C1, C2, C3, C4, C5, C6, C7, C8) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:_:_:_:_:)) Builds an extension scene by combining nine scenes. [`static func buildBlock(C0, C1, C2, C3, C4, C5, C6, C7, C8, C9) -> some AppExtensionScene`](/documentation/ExtensionKit/AppExtensionSceneBuilder/buildBlock(_:_:_:_:_:_:_:_:_:_:)) Builds an extension scene by combining ten scenes. ## Relationships ### Conforms To [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- 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)