# stem_mqtt v0.6.1 - Table of Contents > MQTT 3.1.1/5.0 client and embeddable broker for Elixir and Erlang, in Rust (precompiled NIF) ## Pages - [stem_mqtt](readme.md) ## Modules - [StemMqtt.Broker](StemMqtt.Broker.md): An embeddable MQTT 3.1.1 / 5.0 broker: for tests, edge devices, or an app that is its own broker. - [StemMqtt.Client](StemMqtt.Client.md): An MQTT 3.1.1 / 5.0 client. - [StemMqtt.Message](StemMqtt.Message.md): A PUBLISH delivered to a subscription, sent to the client's owner as `{:stem_mqtt, client.id, {:message, %StemMqtt.Message{}}}`.