Composable events to provide a dynamic user interface are disclosed. In various embodiments, a definition of a custom user interface event is received. The definition includes an identification of a data value to be associated with the event, a scope of the event within which the event will be consumed, and an event trigger in response to which an instance of the custom user interface event is to be published. Application user interface code configured to provide one or more application user interface elements configured to publish or subscribe to the custom user interface event is generated programmatically, based at least in part on the definition.