Kafka

Overview

Truvami supports forwarding decoded messages to your own Kafka cluster. All messages are serialized as JSON. Each Kafka message is wrapped using a consistent envelope format and includes a schema version number.

Kafka Message Envelope

{
  "data": {
    // message content (see below)
  },
  "version": 1
}

This allows forward compatibility with future schema versions.

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Message Types

Uplink

Represents an uplink transmission from a device, including raw payload and radio metadata.

Field	Type	Nullable	Description
uuid	string	No	Unique identifier for the uplink
devEui	string	No	Device EUI (unique identifier)
customer	string	Yes	Customer ID
payload	string	No	Hex-encoded payload data
port	number	No	Port number used for the uplink
uplinkCounter	number	No	Uplink counter for deduplication
downlinkCounter	number	Yes	Downlink counter for deduplication
consumedAirtime	number	Yes	Airtime consumed by the uplink
bestSnr	number	Yes	Best Signal-to-Noise Ratio
worstSnr	number	Yes	Worst Signal-to-Noise Ratio
averageSnr	number	Yes	Average Signal-to-Noise Ratio
bestRssi	number	Yes	Best Received Signal Strength Indicator
worstRssi	number	Yes	Worst Received Signal Strength Indicator
averageRssi	number	Yes	Average Received Signal Strength Indicator
spreadingFactor	number	No	Spreading factor used for the uplink (SF7 - SF12)
confirmed	boolean	No	Whether the uplink is confirmed
receivedAt	string	No	Timestamp when the uplink was received (RFC 3339 format)
dutyCycle	boolean	Yes	Whether duty cycle is applied

Example:

{
  "data": {
    "uuid": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "devEui": "10CE45FFFE01xxxx",
    "customer": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "payload": "hex-string",
    "port": 1,
    "uplinkCounter": 123,
    "downlinkCounter": 12,
    "consumedAirtime": 0.56,
    "bestSnr": 10.2,
    "worstSnr": -3.4,
    "averageSnr": 5.3,
    "bestRssi": -45.0,
    "worstRssi": -105.0,
    "averageRssi": -78.6,
    "spreadingFactor": 12,
    "confirmed": true,
    "receivedAt": "2025-08-06T12:00:00Z",
    "dutyCycle": false
  },
  "version": 1
}

---

Event

Describes a device-level event such as button press or reset.

Field	Type	Nullable	Description
uuid	string	No	Unique identifier for the event
devEui	string	No	Device EUI (unique identifier)
type	number	No	Event type (see EventType enum below)
customer	string	Yes	Customer ID
receivedAt	string	No	Timestamp when the event was received (RFC 3339 format)
occurredAt	string	No	Timestamp when the event occurred (RFC 3339 format)
uplink	string	No	Uplink ID associated with the event

Example:

{
  "data": {
    "uuid": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "devEui": "10CE45FFFE01xxxx",
    "type": 7,
    "customer": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "receivedAt": "2025-07-29T15:12:25.243406716Z",
    "occurredAt": "2025-07-29T14:19:02Z",
    "uplink": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2"
  },
  "version": 1
}

type enum values (EventType)

Value	Meaning
0	Unspecified
1	ButtonPress
2	ConfigChange
3	ManualDeviceReset
4	AutomaticDeviceReset
5	DutyCycle
6	FirmwareChange
7	RotationStatePouring
8	RotationStateMixing
9	RotationStateError
10	RotationStateUndefined

---

RotationStatus

Describes a transition between rotation states (e.g., from mixing to pouring).

Field	Type	Nullable	Description
uuid	string	No	Unique identifier for the rotation status
devEui	string	No	Device EUI (unique identifier)
customer	string	Yes	Customer ID
uplink	string	No	Uplink ID associated with the rotation status
lastState	number	No	Previous rotation state (see RotationStatusType enum below)
newState	number	No	New rotation state (see RotationStatusType enum below)
rotations	number	Yes	Number of rotations completed during the state transition
elapsedSeconds	number	No	Time elapsed during the state transition in seconds
receivedAt	string	No	Timestamp when the rotation status was received (RFC 3339 format)
capturedAt	string	No	Timestamp when the rotation status was captured (RFC 3339 format)
sequenceNumber	number	No	Sequence number for deduplication

Example:

{
  "data": {
    "uuid": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "devEui": "10CE45FFFE01xxxx",
    "customer": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "uplink": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "lastState": 1,
    "newState": 2,
    "rotations": 2.5,
    "elapsedSeconds": 60,
    "receivedAt": "2025-08-06T12:00:00Z",
    "capturedAt": "2025-08-06T11:59:50Z",
    "sequenceNumber": 42
  },
  "version": 1
}

lastState / newState enum values (RotationStatusType)

Value	Meaning
0	undefined
1	pouring
2	mixing
3	error

---

Position

Provides location data captured by the device (GNSS, LoRa, Wi-Fi, BLE).

Field	Type	Nullable	Description
uuid	string	No	Unique identifier for the position
devEui	string	No	Device EUI (unique identifier)
customer	string	Yes	Customer ID
uplink	string	No	Uplink ID associated with the position
latitude	number	No	Latitude in decimal degrees
longitude	number	No	Longitude in decimal degrees
altitude	number	Yes	Altitude in meters
accuracy	number	Yes	Horizontal accuracy in meters
source	number	No	Source of position data (see PositionSource enum below)
moving	boolean	Yes	Whether the device is moving
buffered	boolean	No	Whether the position is buffered
bufferLevel	number	Yes	Buffer level indicating how full the buffer is
receivedAt	string	No	Timestamp when the position was received (RFC 3339 format)
capturedAt	string	No	Timestamp when the position was captured (RFC 3339 format)
ttf	number	Yes	Time to first fix in seconds
pdop	number	Yes	Position Dilution of Precision (PDOP) value
satellites	number	Yes	Number of satellites used for the position fix

Example:

{
  "data": {
    "uuid": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "devEui": "10CE45FFFE01xxxx",
    "customer": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "uplink": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "latitude": 4.13743,
    "longitude": 2.57549,
    "altitude": 520.5,
    "accuracy": 3.2,
    "source": 0,
    "moving": true,
    "buffered": false,
    "bufferLevel": 0,
    "receivedAt": "2025-08-06T12:00:00Z",
    "capturedAt": "2025-08-06T11:59:30Z",
    "ttf": 8,
    "pdop": 1.5,
    "satellites": 6
  },
  "version": 1
}

source enum values (PositionSource)

Value	Meaning
0	gnss
1	lora
2	wifi
3	ble

---

BatteryStatus

Provides battery voltage readings.

Field	Type	Nullable	Description
uplink	string	No	Uplink ID associated with the battery status
devEui	string	No	Device EUI (unique identifier)
customer	string	Yes	Customer ID
voltage	number	No	Battery voltage in volts
receivedAt	string	No	Timestamp when the battery status was received (RFC 3339 format)
capturedAt	string	No	Timestamp when the battery status was captured (RFC 3339 format)

Example:

{
  "data": {
    "uplink": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "devEui": "10CE45FFFE01xxxx",
    "customer": "126cd4ea-4c15-4cd7-b2a0-9860b5088fc2",
    "voltage": 3.65,
    "receivedAt": "2025-08-06T12:00:00Z",
    "capturedAt": "2025-08-06T11:59:55Z"
  },
  "version": 1
}

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Additional Notes

• Timestamps use RFC 3339 format and are in UTC.
• Enum values are serialized as integers.
• All messages are wrapped using the same envelope structure containing a data object and a version field.