MQTT Version 5 Features

MQTTnet supports MQTT V5 Packets. Feature support is not 100 % yet and is being extended from time to time. The following tables shows which feature is already available for MQTTnet clients and servers. Features which are not listed here are not officially supported.

Feature	Client	Server	Library version
Connection Features
Assigned Client ID	Supported	Supported	3.1.0 +
Empty User Name	Can be omitted when connecting.	Supported	3.1.0 +
Server reference	Can be read from connect result but no auto redirect.	Supported	3.1.0 +
Publish Features
Topic Alias	Can be set when publishing.	Supported	3.1.0 +
Subscribe Features
No Local	Can be set in MqttTopicFilterBuilder.	Supported	3.1.0 +
Retain As Published	Can be set in MqttTopicFilterBuilder.	Supported	3.1.0 +
Retain Handling	Can be set in MqttTopicFilterBuilder.	Supported	3.1.0 +
Shared Subscriptions	Not supported	Not supported	-
Subscription Identifiers	Can be set when subscribing.	Supported	3.1.0 +
Wildcard Subscription Available	Can be set when subscribing.	Supported	3.1.0 +
Server Features
$SYS	Not supported	Not supported	-