MQTT Operation Binding v0.1.0

The MQTT operation binding v0.1.0 allows for defining behavior specific to an MQTT publish or subscribe operation, including Quality of Service (QoS) and the retain flag.

Overview

This binding provides operation-level control over how messages are handled by the MQTT broker, which is essential for defining the reliability and storage policies for a specific interaction.

Operation Properties

Property	Type	Required	Description
bindingVersion	string	No	Binding version (defaults to 0.1.0)
qos	integer	No	Defines the Quality of Service level. Must be 0, 1, or 2. Defaults to 0.
retain	boolean	No	Whether the message should be retained by the broker. Defaults to false.

Property Details

qos

Quality of Service (QoS) determines the guarantee of message delivery.

• 0: At most once.
• 1: At least once.
• 2: Exactly once.

retain

If true, the MQTT broker will store this message as the "last known good" value for its topic. New subscribers will receive this message immediately upon subscribing.

Example

This operation sends a device status message with QoS 1 and instructs the broker to retain it.

operations:
  publishDeviceStatus:
    action: send
    channel:
      $ref: '#/channels/deviceStatus'
    bindings:
      mqtt:
        bindingVersion: '0.1.0'
        qos: 1
        retain: true

Changelog

Version 0.1.0

• Initial legacy release of the MQTT operation binding.
• Added qos and retain properties.