# DistributedTargetInvocationResultHandler Protocol a distributed invocation execution’s result handler. ``` protocol DistributedTargetInvocationResultHandler ``` ## Overview An instance conforming to this type must be passed when invoking [`executeDistributedTarget(on:target:invocationDecoder:handler:)`](/documentation/Distributed/DistributedActorSystem/executeDistributedTarget(on:target:invocationDecoder:handler:)) while handling an incoming distributed call. The handler will then be invoked with the return value (or error) that the invoked target returned (or threw). ## Topics ### Associated Types [`associatedtype SerializationRequirement`](/documentation/Distributed/DistributedTargetInvocationResultHandler/SerializationRequirement) The serialization requirement that the value passed to `onReturn` is required to conform to. ### Instance Methods [`func onReturn(value: Success) async throws`](/documentation/Distributed/DistributedTargetInvocationResultHandler/onReturn(value:)) Invoked when the distributed target execution returns successfully. The `value` is the return value of the executed distributed invocation target. [`func onReturnVoid() async throws`](/documentation/Distributed/DistributedTargetInvocationResultHandler/onReturnVoid()) Invoked when the distributed target execution of a `Void` returning function has completed successfully. [`func onThrow(error: Err) async throws`](/documentation/Distributed/DistributedTargetInvocationResultHandler/onThrow(error:)) Invoked when the distributed target execution of a target has thrown an error. ## Relationships ### Conforming Types [`LocalTestingInvocationResultHandler`](/documentation/Distributed/LocalTestingInvocationResultHandler) --- 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)