MQTT
Lightweight pub/sub transport for telemetry and events.
A lightweight publish/subscribe messaging protocol (OASIS standard): clients publish to topic strings on a broker, subscribers receive matching messages. Features QoS levels, retained messages, persistent sessions, and Last Will. Defines transport only — topic structure and payloads come from conventions like Sparkplug.
See also: Sparkplug B · Unified namespace · QoS (MQTT)