Device Power Lost Event

device.power.lost is sent when a device detects power loss.

Topic

device.power.lost

Permission

Required:

device:read

Event

{
  "type": "event",
  "topic": "device.power.lost",
  "data": {
    "deviceId": "abc123456789",
    "occurredAt": "2026-05-08T09:34:46Z",
    "message": "equipment is power off 2026-05-08 09:37:43"
  }
}

data Schema

Field	Type	Required	Description
deviceId	string	Yes	Unique device identifier
occurredAt	string	Yes	Event time recorded by the server, in RFC3339 UTC
message	string	No	Raw device message for debugging and logs only. Its format is not guaranteed to stay stable

Rules

• The event is reported by the device before power is lost, and the service pushes it to connected clients
• The device usually goes offline immediately after power loss, so the client should then receive device.connection.offline
• The message field comes from device firmware; its content and format depend on the device implementation, so clients must not branch on it programmatically
• After receiving a power loss event, the client should no longer assume that the device can still be controlled

Client Handling Suggestions

• Record the event for alerting or audit purposes
• Wait for device.connection.offline to confirm that the device is offline
• Commands sent during the power loss window will return DEVICE_OFFLINE