Systems, methods and apparatus for invoking actions at a second user device from a first user device. A method includes determining that a first user device has an associated second user device; accessing specification data that specifies a set of user device actions that the second user device is configured to perform; receiving command inputs for the first user device; for each command input, determining whether the command input resolves to one of the user device actions; for each command input not determined to resolve any of the user device actions, causing the command input to be processed at the first user device; and for each command input determined to resolve one of the user device actions causing the first user device to display in a user interface a dialog by which a user may either accept or deny invoking the user device action at the second user device.