A button entity is an entity that can fire an event / trigger an action towards a device or service but remains stateless from the Home Assistant perspective.
It can be compared to a real live momentary switch, push-button, or some other form of a stateless switch.
The button entities cannot be implemented manually, but can be provided by other integrations.
The button entity is stateless, as in, it cannot have a state like the
off state that, for example, a normal switch entity has.
Every button entity does keep track of the timestamp of when the last time the button entity has been pressed in the Home Assistant UI or pressed via a service call.
Because the state of a button entity in Home Assistant is a timestamp, it means we can use it in our automations. For example:
trigger: - platform: state entity_id: button.my_button action: - service: notify.frenck data: message: "My button has been pressed!"
The button entities exposes a single service:
This service can be called to trigger a button press for that entity.
- service: button.press target: entity_id: button.my_button
The way these buttons are displayed in the frontend can be modified in the customize section. The following device classes are supported for buttons:
Example of device class icons.
- None: Generic button. This is the default and doesn’t need to be set.
- identify: The button is used to identify a device.
- restart: The button restarts the device.
- update: The button updates the software of the device.