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user property

A name-value label an MQTT 5 message can carry alongside its payload.

User properties are application-defined UTF-8 name-value pairs carried in the MQTT 5 packet's properties, readable without parsing the payload.

Examples

  • A node can label each reading with the user property ("fw", "1.4.2") so the logger knows its firmware version, but an API key must never go there because every subscriber can read it.

See also

message contract reason code shared subscription
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