---
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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