Abstract: A digital assistant supported on devices such as smartphones, tablets, personal computers, game consoles, etc. includes an extensibility client that exposes an interface and service that enables third party applications to be integrated with the digital assistant so the application user experiences are rendered using the native voice of the digital assistant. Specific voice inputs associated with a given application may be registered by developers using a manifest that is loaded when the application is launched on the device so that voice inputs from the device user can be mapped by the digital assistant extensibility client to the appropriate application as input events for consumption. In typical implementations, the manifest is arranged as a declarative document that streamlines application development and provides a seamless user experience by enabling customization of third party applications to integrate the digital assistant's voice and behaviors within the user experience of the application's domain.