In a system in which an in-home audio device is supported by a network-based support service, certain aspects of the behavior of the audio device may be implemented as a state machine. A graphical user interface (GUI) may be provided by the support service to allow editing of a model representing the state machine of the device. Through the GUI, a user or developer can associate functions with states or state transitions of the state machine. In addition, the user or developer can associate custom code with individual states or state transitions of the state machine.