During installation, a [MQTT](https://en.wikipedia.org/wiki/MQTT) broker, [Mosquitto](https://mosquitto.org/), is installed at the same time as Domoticz.
To use Mosquitto, you need to customize the communication between Domoticz and the broker by following the [domoticz documentation](https://www.domoticz.com/wiki/MQTT#Installing_Mosquitto), part *Add hardware "MQTT Client Gateway"*.
- open port 1883 on YunoHost firewall (**Attention, security risk**)
- Allows IP addresses in Mosquitto configuration for this listener
- Set the tls setting in Mosquitto configuration by giving access to crt.pem and key.pem from your mqtt domain by setting respective certfile et keyfile variables. **This is mandatory to ensure a secure connection.**
If you're using Zwave devices, install Mosquitto along Domoticz and give a try to [zwave-JS-UI package](https://github.com/YunoHost-Apps/zwave-js-ui_ynh).
Once installed, just follow instructions from the [wiki](https://www.domoticz.com/wiki/Zwave-JS-UI)
### Access and API
By default, access for the [JSON API](https://www.domoticz.com/wiki/Domoticz_API/JSON_URL's) is allowed on following path `/yourdomain.tld/api_/domoticzpath`.
So if you access Domoticz via https://mydomainname.tld/domoticz, use the following webpath for the API: `/mydomainname.tld/api_/domoticz/json.htm?yourapicommand`
As far as I know, there is no way to filter for IPv6 address on local network: You may remove the authorization by removing or commenting this line in `/etc/nginx/conf.d/yourdomain.tld.d/domoticz.conf`: