Device State Changed Event

device.state.changed is sent when device IO state changes.

Topic

device.state.changed

Event — Triggered by Remote Control

When triggered by an API command, reason is remoteControl and correlationId is the request requestId that caused the change.

{
  "type": "event",
  "topic": "device.state.changed",
  "data": {
    "deviceId": "abc123456789",
    "occurredAt": "2026-04-03T00:41:44Z",
    "reason": "remoteControl",
    "correlationId": "req_op_001",
    "peripherals": {
      "relays": [
        {
          "index": 1,
          "on": true
        },
        {
          "index": 2,
          "on": false
        },
        {
          "index": 3,
          "on": false
        },
        {
          "index": 4,
          "on": false
        }
      ],
      "digitalInputs": [
        {
          "index": 1,
          "active": false
        },
        {
          "index": 2,
          "active": false
        },
        {
          "index": 3,
          "active": false
        },
        {
          "index": 4,
          "active": false
        }
      ],
      "sensors": [
        {
          "index": 1,
          "type": "TEMP",
          "value": 30.4,
          "unit": "C",
          "status": "ONLINE"
        },
        {
          "index": 2,
          "type": "TEMP",
          "value": 32.6,
          "unit": "C",
          "status": "ONLINE"
        },
        {
          "index": 2,
          "type": "HUMI",
          "value": 54,
          "unit": "%",
          "status": "ONLINE"
        }
      ]
    },
    "stateUpdatedAt": "2026-04-03T00:41:44Z"
  }
}

Event — Triggered on the Device Side

When triggered locally by the device, reason is localChange and correlationId is not included.

{
  "type": "event",
  "topic": "device.state.changed",
  "data": {
    "deviceId": "abc123456789",
    "occurredAt": "2026-04-03T00:41:44Z",
    "reason": "localChange",
    "peripherals": {
      "relays": [
        {
          "index": 1,
          "on": false
        },
        {
          "index": 2,
          "on": false
        },
        {
          "index": 3,
          "on": false
        },
        {
          "index": 4,
          "on": false
        }
      ],
      "digitalInputs": [
        {
          "index": 1,
          "active": false
        },
        {
          "index": 2,
          "active": false
        },
        {
          "index": 3,
          "active": false
        },
        {
          "index": 4,
          "active": false
        }
      ],
      "sensors": [
        {
          "index": 1,
          "type": "TEMP",
          "value": 30.4,
          "unit": "C",
          "status": "ONLINE"
        },
        {
          "index": 2,
          "type": "TEMP",
          "value": 32.6,
          "unit": "C",
          "status": "ONLINE"
        },
        {
          "index": 2,
          "type": "HUMI",
          "value": 54,
          "unit": "%",
          "status": "ONLINE"
        }
      ]
    },
    "stateUpdatedAt": "2026-04-03T00:41:44Z"
  }
}

data Schema

Field	Type	Required	Description
deviceId	string	Yes	Unique device identifier
occurredAt	string	Yes	Event time in RFC3339 UTC
reason	string	No	Reason for the state change. See the table below
correlationId	string	No	Related request ID. Present only when reason=remoteControl
peripherals	object	Yes	Complete peripheral state data
stateUpdatedAt	string	Yes	Device state update time in RFC3339 UTC

reason Enum

Value	Trigger Scenario	correlationId
remoteControl	Triggered by an API command (device.operation.execute or a REST relay command)	The corresponding request requestId
localChange	Triggered on the device side. Due to firmware limitations, the precise local source is unknown; it may be a panel button, a digital input, or another local hardware event	Not present

Rules

• data.peripherals reuses the peripherals schema from REST device detail responses
• data.peripherals is complete peripheral state data, not an incremental diff
• Clients should replace the current device hardware state with the full block from the event
• The reason field may be missing. If it is missing, clients should not assume a trigger source