---
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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