home-assistant.io/source/components/sensor.rest.markdown

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layout	title	description	date	sidebar	comments	sharing	footer
page	RESTful sensor support	Instructions how to integrate REST sensors into Home Assistant.	2015-09-14 19:10	false	false	true	true

The rest sensor platform is consuming a give endpoint which is exposed by a [RESTful API](https://en.wikipedia.org/wiki/Representational_state_transfer) 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 for a GET request:

# Example configuration.yaml entry
sensor:
  platform: rest
  resource: http://IP_ADDRESS/ENDPOINT
  method: GET
  name: REST GET sensor
  variable: 'return_value'
  unit_of_measurement: "°C"
  correction_factor: 0.01
  decimal_places: 0

or for a POST request:

# Example configuration.yaml entry
sensor:
  platform: rest
  resource: http://IP_ADDRESS/ENDPOINT
  method: POST
  variable: 'temperature' or ['Temperatures', 0, 'CurrentReading']
  payload: '{ "device" : "heater" }'
  name: REST POST sensor
  unit_of_measurement: "°C"
  correction_factor: 0.0001
  decimal_places: 0

Configuration variables:

• resource (Required): The resource or endpoint that contains the value.
• method (Optional): The method of the request. Default is GET.
• variable (Optional): Defines the variable or a list of element for complex responses to extract, if any.
• 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.
• correction_factor (Optional): A float value to do some basic calculations.
• decimal_places (Optional): Number of decimal places of the value. Default is 0.

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}

{% linkable_title Examples %}

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

{% linkable_title 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
    variable: 'ip'

{% linkable_title Single value from a local Glances instance %}

The glances sensor is doing a similar thing

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
    variable: 'used'
    unit_of_measurement: MB
    correction_factor: 0.000000954
    decimal_places: 0