---

labels:

- 'Stage-Beta'

summary: 'MQTT interface to Prosody''s pubsub'

...

Introduction

------------

[MQTT](http://mqtt.org/) is a lightweight binary pubsub protocol suited

to embedded devices. This module provides a way for MQTT clients to

connect to Prosody and publish or subscribe to local pubsub nodes.

Details

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MQTT has the concept of 'topics' (similar to XMPP's pubsub 'nodes').

mod\_pubsub\_mqtt maps pubsub nodes to MQTT topics of the form

`HOST/NODE`, e.g.`pubsub.example.org/mynode`.

### Limitations

The current implementation is quite basic, and in particular:

-   Authentication is not supported

-   SSL/TLS is not supported

-   Only QoS level 0 is supported

### Payloads

XMPP payloads are always XML, but MQTT does not define a payload format.

Therefore mod\_pubsub\_mqtt will attempt to convert data of certain

recognised payload types. Currently supported:

-   JSON (see [XEP-0335](http://xmpp.org/extensions/xep-0335.html) for

    the format)

-   Plain UTF-8 text (wrapped inside

    `<data xmlns="https://prosody.im/protocol/mqtt"/>`)

All other XMPP payload types are sent to the client directly as XML.

Data published by MQTT clients is currently never translated, and always

treated as UTF-8 text.

Configuration

-------------

There is no special configuration for this module. Simply load it on

your pubsub host like so:

    Component "pubsub.example.org" "pubsub"

        modules_enabled = { "pubsub_mqtt" }

You may also configure which port(s) mod\_pubsub\_mqtt listens on using

Prosody's standard config directives, such as `mqtt_ports`. Network

settings **must** be specified in the global section of the config file,

not under any particular pubsub component. The default port is 1883

(MQTT's standard port number).

Compatibility

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  trunk   Works

  0.9     Works

  0.8     Doesn't work

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