---
layout: page
title: "JSON MQTT Device Tracker"
description: "Instructions how to use JSON MQTT to track devices in Home Assistant."
date: 2017-04-12 20:41
sidebar: true
comments: false
sharing: true
footer: true
logo: mqtt.png
ha_category: Presence Detection
ha_version: 0.44
ha_iot_class: depends
---


The `mqtt_json` device tracker platform allows you to detect presence by monitoring an MQTT topic for new locations. To use this platform, you specify a unique topic for each device.

To use this device tracker in your installation, add the following to your `configuration.yaml` file:

```yaml
# Example configuration.yaml entry
device_tracker:
  - platform: mqtt_json
    devices:
      paulus_oneplus: location/paulus
      annetherese_n4: location/annetherese
```

Configuration variables:

- **devices** (*Required*): List of devices with their topic.
- **qos** (*Optional*): The QoS level of the topic.

This platform receives JSON formatted payloads containing GPS information, for example:

```json
{"longitude": 1.0,"gps_accuracy": 60,"latitude": 2.0,"battery_level": 99.9}
```

Where `longitude` is the longitude, `latitude` is the latitude, `gps_accuracy` is the accuracy in meters, `battery_level` is the current battery level of the device sending the update.
`longitude` and `latitude` are required keys, `gps_accuracy` and `battery_level` are optional.