Topic
Properties
A UTF-8 encoded string that describes the content of the publishing message. For more information, see Content Type in the MQTT Version 5.0 specification. Supports substitution templates .
The base64-encoded binary data used by the sender of the request message to identify which request the response message is for. For more information, see Correlation Data in the MQTT Version 5.0 specification. Supports substitution templates .
A user-defined integer value that represents the message expiry interval at the broker. If the messages haven't been sent to the subscribers within that interval, the message expires and is removed. The value of messageExpiry represents the number of seconds before it expires. For more information about the limits of messageExpiry , see Message broker and protocol limits and quotas in the IoT Core Reference Guide. Supports substitution templates .
An Enum string value that indicates whether the payload is formatted as UTF-8. Valid values are UNSPECIFIED_BYTES and UTF8_DATA . For more information, see Payload Format Indicator from the MQTT Version 5.0 specification. Supports substitution templates .
A UTF-8 encoded string that's used as the topic name for a response message. The response topic is used to describe the topic to which the receiver should publish as part of the request-response flow. The topic must not contain wildcard characters. For more information, see Response Topic in the MQTT Version 5.0 specification. Supports substitution templates .
An array of key-value pairs that you define in the MQTT5 header.