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Subscriptions

Subscriptions list showing active routing rules between endpoints and destinations

A subscription is the rule that connects your endpoint data to a destination. Without a subscription, data collected from devices goes nowhere.

The Idea​

Think of it as a pipe with filters. You specify:

  • What data — which protocol(s) to pull from (Modbus, OPC-UA, BACnet, or all of them)
  • Where it goes — which destination to send to
  • How it's formatted — the payload format the destination expects
  • Which topic/measurement — the MQTT topic or InfluxDB measurement to write to

Adding a Subscription​

New Subscription drawer with destination, protocol, and payload format fields

  1. Go to Subscriptions in the sidebar and click New Subscription.
  2. Select a Destination from the dropdown.
  3. Set the Source Protocol — leave it empty to receive data from all endpoints, or pick a specific protocol.
  4. Choose a Payload Format (see below).
  5. Enter the Destination Topic (for MQTT) or Measurement name (for InfluxDB).
  6. Click Save.

Data starts flowing immediately if the destination is reachable.

Payload Formats​

The payload format controls how readings are serialized before being sent to the destination.

Custom (default)​

A JSON envelope containing protocol metadata and the full array of readings:

{
  "timestamp": "2026-06-21T12:00:00.000Z",
  "protocol": "modbus",
  "messages": [
    { "name": "temperature", "value": 24.5 },
    { "name": "pressure", "value": 1.02 }
  ]
}

Good for MQTT destinations where you want to process the full batch on the receiving end.

Tags​

A flat structure with a node name and a list of named tag/field pairs:

{
  "node": "Chiller-1",
  "group": "Chiller",
  "tags": [
    { "name": "temperature", "value": 24.5 },
    { "name": "pressure", "value": 1.02 }
  ]
}

Recommended for InfluxDB. The agent maps tag names to InfluxDB fields and the device name to an InfluxDB tag, giving you clean time-series data ready for Grafana.

ECP​

A compact industrial format compatible with Sparkplug-style tooling. Tags with errors or null values are omitted from the output. Best for integrations with systems that expect ECP payloads.

Filtering by Device or Metric​

Under Advanced Routing in the subscription drawer you can narrow what data is included:

  • Include devices — only include readings from specific endpoint names
  • Exclude devices — send everything except specific endpoints
  • Include metrics — whitelist specific metric names
  • Exclude metrics — send everything except specific metrics

Leave all filters empty to send all data from the selected protocol.

One Source, Many Destinations​

You can create multiple subscriptions from the same protocol to different destinations. For example:

  • Subscription A: all Modbus data → local MQTT broker (format: custom)
  • Subscription B: all Modbus data → InfluxDB (format: tags)

Both run simultaneously. The agent publishes each batch to all matching subscriptions in parallel.

Measurement Override (InfluxDB)​

For InfluxDB subscriptions, the Destination Topic field acts as a measurement name override. If you leave it blank, data goes into the measurement name set on the destination itself (default: metrics). Set it here to route specific subscriptions to a different measurement — for example, putting BACnet readings into hvac_data and Modbus into electrical_data.