# TransientComponent An interface for components that aren’t saved to file or cloned. ``` protocol TransientComponent : Component ``` ## Overview Components that conform to the [`TransientComponent`](/documentation/RealityKit/TransientComponent) protocol aren’t included when RealityKit serializes its owning entity to save it to a file. Similarly, when you clone an entity, any transient components on that entity aren’t copied to the clone. To ensure that cloned entities, or entities saved to file get a copy of the transient component with default values, create and initialize the component in your entity’s `init()` method: ```swift class MyEntity: Entity { required init() { let newComponent = MyComponent() components[MyComponent.self] = newComponent return newComponent } } ``` Alternatively, you can create a computed property for your component that initializes it to default values the first time your code accesses it. ```swift class MyEntity: Entity { var myComponent: MyComponent { // If the component exists, return it. if let component = components[MyComponent.self] { return component } // Create a new component and return it. components[MyComponent.self] = MyComponent() return newComponent } } ``` Use transient components to represent runtime state for an entity. For example, an entity representing a fish in a virtual aquarium might store attributes such as hunger in a transient component. In networked AR experiences, RealityKit sends transient components to peers when it sends the entity, if the component also conforms to . If transient components don’t conform, ReaityKit still sends the entity to network peers, but it excludes the transient component. ## Relationships ### Conforming Types [`ComputeGraphViewpointComponent`](/documentation/RealityKit/ComputeGraphViewpointComponent) [`ComputeGraphSharedUniforms`](/documentation/RealityKit/ComputeGraphSharedUniforms) [`ARKitAnchorComponent`](/documentation/RealityKit/ARKitAnchorComponent) [`ViewAttachmentComponent`](/documentation/RealityKit/ViewAttachmentComponent) [`ComputeGraphOutputComponent`](/documentation/RealityKit/ComputeGraphOutputComponent) [`PresentationComponent`](/documentation/RealityKit/PresentationComponent) [`ComputeGraphRuntimeComponent`](/documentation/RealityKit/ComputeGraphRuntimeComponent) ### Inherits From [`Component`](/documentation/RealityKit/Component) --- 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)