1. A system comprising: one or more server computers; one or more server applications that have been selected by a user for execution on the one or more server computers, wherein the one or more server applications operate in conjunction with a speech interface device located in premises of the user to provide services for the user; a speech processing component configured to receive, from the speech interface device, an audio signal that represents user speech, wherein the user speech expresses a user intent, the speech processing component being further configured to perform automatic speech recognition on the audio signal to identify the user speech and to perform natural language understanding on the user speech to determine the user intent; and an intent router configured to perform acts comprising: identifying a first server application of the one or more server applications corresponding to the user intent; providing a first indication to the first server application to invoke an action corresponding to the user intent; providing a second indication of the user intent to the speech interface device, wherein the speech interface device is responsive to the user intent to perform the action corresponding to the user intent; receiving, at the one or more server computers, a confirmation from the speech interface device that at least one of (i) the speech interface device will perform the action in response to the user intent or (ii) the speech interface device has performed the action in response to the user intent; and providing a third indication, based at least in part on receiving the confirmation, to the first server application to cancel responding to the user intent.