Home Assistant

RESTful sensor

The rest sensor platform is consuming a given endpoint which is exposed by a RESTful API of a device, an application, or a web service. The sensor has support for GET and POST requests.

To enable this sensor, add the following lines to your configuration.yaml file for a GET request:

# Example configuration.yaml entry
sensor:
  platform: rest
  resource: http://IP_ADDRESS/ENDPOINT
  value_template: '{{ value_json.thermostat }}'
  method: GET
  name: REST GET sensor
  unit_of_measurement: "°C"

or for a POST request:

# Example configuration.yaml entry
sensor:
  platform: rest
  resource: http://IP_ADDRESS/ENDPOINT
  method: POST
  value_template: '{{ value_json.thermostat }}'
  payload: '{ "device" : "heater" }'
  name: REST POST sensor
  unit_of_measurement: "°C"

Configuration variables:

  • resource (Required): The resource or endpoint that contains the value.
  • method (Optional): The method of the request. Default is GET.
  • value_template (Optional): Defines a template to extract the value.
  • payload (Optional): The payload to send with a POST request. Usualy formed as a dictionary.
  • name (Optional): Name of the REST sensor.
  • unit_of_measurement (Optional): Defines the unit of measurement of the sensor, if any.

Make sure that the URL matches exactly your endpoint or resource.

curl could help you with the identification of the variable you want to display in your Home Assistant frontend. The example below show the JSON response of a device that is running with aREST.

$ curl -X GET http://192.168.1.31/temperature/
{"temperature": 77, "id": "sensor02", "name": "livingroom", "connected": true}

Examples

In this section you find some real life examples of how to use this sensor.

External IP address

Always want to know your external IP address. JSON Test will provide you this information at their http://ip.jsontest.com/ endpoint.

To display the IP address, the entry for a sensor in the configuration.yaml file will look like this.

# Example configuration.yaml entry
  - platform: rest
    resource: http://ip.jsontest.com
    name: External IP
    value_template: '{{ value_json.ip }}'

Single value from a local Glances instance

The glances sensor is doing the exact same thing for all exposed values.

Add something similar to the entry below to your configuration.yaml file:

# Example configuration.yaml entry
  - platform: rest
    resource: http://IP_ADRRESS:61208/api/2/mem/used
    name: Used mem
    value_template: '{{ value_json.used| multiply(0.000000954) | round(0) }}'
    unit_of_measurement: MB