Three days ago, Roger Light, the main author of the Mosquitto MQTT broker, announced that
The work on MQTT v5 support in Mosquitto has reached a point where it may be of interest to a range of people. It is not yet complete, but wider testing and feedback would be appreciated.
The source is available at mosquitto-mqtt5-test1.tar.gz and can be compiled as normal.
Supported features
- Session expiry
- Message expiry
- Reason code on all ACKs (not all reason codes are used)
- Reason string on all ACKs (no reason strings are provided by the broker however)
- Payload format and content type
- Request / response pattern
- Subscription ID
- Topic alias
- Flow control
- User properties
- Optional server feature availability
- Subscription options
- Server keep alive
- Assigned Client ID
Unsupported features
- Shared subscriptions
- Extended authentication
- Server reference
- Not all reason codes are used by the broker
- Bridges do not use MQTT v5
- On disk persistence does not include MQTT 5 property support
- The broker will not create topic aliases