---

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.

The module currently implements MQTT version 3.1.1.

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>/<TYPE>/<NODE>`, e.g.`pubsub.example.org/json/mynode`.

The 'TYPE' parameter in the topic allows the client to choose the payload

format it will send/receive. For the supported values of 'TYPE' see the

'Payloads' section below.

### Limitations

The current implementation is quite basic, and in particular:

-   Authentication 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 has some built-in data format translators.

Currently supported data types:

-   `json`: See [XEP-0335](http://xmpp.org/extensions/xep-0335.html) for

    the format.

-   `utf8`: Plain UTF-8 text (wrapped inside

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

-   `atom_title`: Returns the title of an Atom entry as UTF-8 data

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` and

`mqtt_tls_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) and 8883 for TLS connections.

Compatibility

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

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  trunk   Works

  0.12    Works

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