The root of the topic tree where HA is listening for messages"
The topic on which Home Assistant publishes its birth message ("online") when it starts. When received, all discovery configs are re-published. Set to null to disable this behaviour.
The root of the topic tree ha-mqtt-discovery publishes its state messages
Message expiry interval in seconds for retained discovery config messages (MQTT v5). Stale configs are automatically purged from the broker after this duration. Set to null or Infinity to retain without expiry. Default: 28 days.