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

or for a POST request:

# Example configuration.yaml entry
sensor:
  - platform: rest
    resource: http://IP_ADDRESS/ENDPOINT
    method: POST
    payload: '{ "device" : "heater" }'

curl can help you identify the variable you want to display in your Home Assistant frontend. The example below shows 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

You can find your external IP address using the service JSON Test at their http://ip.jsontest.com/ URL.

sensor:
  - 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.

sensor:
  - 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

Value from another Home Assistant instance

The Home Assistant API exposes the data from your attached sensors. If you are running multiple Home Assistant instances which are not connected you can still get information from them.

If the Home Assistant instance in the resource variable is protected by an API password, you can append ?api_password=YOUR_PASSWORD to the resource URL to authenticate or use headers:.

sensor:
  - platform: rest
    resource: http://IP_ADDRESS:8123/api/states/sensor.weather_temperature
    name: Temperature
    value_template: '{{ value_json.state }}'
    unit_of_measurement: "°C"

Accessing an HTTP authentication protected endpoint

The REST sensor supports HTTP authentication and customized headers.

sensor:
  - platform: rest
    resource: http://IP_ADDRESS:5000/sensor
    username: ha1
    password: test1
    authentication: basic
    headers:
      User-Agent: Home Assistant
      Content-Type: application/json

The headers will contain all relevant details. This will also give you the ability to access endpoints that are protected by tokens.

Content-Length: 1024
Host: IP_ADDRESS1:5000
Authorization: Basic aGExOnRlc3Qx
Accept-Encoding: identity
Content-Type: application/json
User-Agent: Home Assistant

If you are accessing a resource protected by a Bearer token in an Authorization header, you can either put the token in the header field of the sensor configuration (not recommended) or store the token in your secrets.yaml file. In that case, be sure to include the word Bearer in the secrets file.

sensor:
  - platform: rest
    resource: http://IP_ADDRESS:5000/sensor
    headers:
      Authorization: !secret my_sensor_secret_token

Example entry for the secrets.yaml file:

my_sensor_secret_token: Bearer gh_DHQIXKVf6Pr4H8Yqz8uhApk_mnV6Zje6Pr4H8Yqz8A8nCxz6SBghQdS51

Use GitHub to get the latest release of Home Assistant

This sample is very similar to the updater integration but the information is received from GitHub.

sensor:
  - platform: rest
    resource: https://api.github.com/repos/home-assistant/home-assistant/releases/latest
    username: YOUR_GITHUB_USERNAME
    password: YOUR_GITHUB_ACCESS_TOKEN
    authentication: basic
    value_template: '{{ value_json.tag_name }}'
    headers:
      Accept: application/vnd.github.v3+json
      Content-Type: application/json
      User-Agent: Home Assistant REST sensor

Fetch multiple JSON values and present them as attributes

JSON Test returns the current time, date and milliseconds since epoch from http://date.jsontest.com/.

sensor:
  - platform: rest
    name: JSON time
    json_attributes:
      - date
      - milliseconds_since_epoch
    resource: http://date.jsontest.com/
    value_template: '{{ value_json.time }}'
  - platform: template
    sensors:
      date:
        friendly_name: 'Date'
        value_template: '{{ states.sensor.json_time.attributes["date"] }}'
      milliseconds:
        friendly_name: 'milliseconds'
        value_template: '{{ states.sensor.json_time.attributes["milliseconds_since_epoch"] }}'

This sample fetches a weather report from OpenWeatherMap, maps the resulting data into attributes of the RESTful sensor and then creates a set of template sensors that monitor the attributes and present the values in a usable form.

sensor:
  - platform: rest
    name: OWM_report
    json_attributes:
      - main
      - weather
    value_template: '{{ value_json["weather"][0]["description"].title() }}'
    resource: https://api.openweathermap.org/data/2.5/weather?zip=80302,us&APPID=VERYSECRETAPIKEY
  - platform: template
    sensors:
      owm_weather:
        value_template: '{{ state_attr('sensor.owm_report', 'weather')[0]["description"].title() }}'
        entity_picture_template: '{{ "https://openweathermap.org/img/w/"+state_attr('sensor.owm_report', 'weather')[0]["icon"].lower()+".png" }}'
        entity_id: sensor.owm_report
      owm_temp:
        friendly_name: 'Outside temp'
        value_template: '{{ state_attr('sensor.owm_report', 'main')["temp"]-273.15 }}'
        unit_of_measurement: "°C"
        entity_id: sensor.owm_report
      owm_pressure:
        friendly_name: 'Outside pressure'
        value_template: '{{ state_attr('sensor.owm_report', 'main')["pressure"] }}'
        unit_of_measurement: "hP"
        entity_id: sensor.owm_report
      owm_humidity:
        friendly_name: 'Outside humidity'
        value_template: '{{ state_attr('sensor.owm_report', 'main')["humidity"] }}'
        unit_of_measurement: "%"
        entity_id: sensor.owm_report

This config shows how to extract multiple values from a dictionary with json_attributes and template. It helps you to avoid flooding the REST service and only ask once the results and separate them in multiple templates referring to it. (No need for a specific state on the REST sensor and it’s default state will be the full JSON value which will be longer than the 255 max length. It’s why we’ll used a static value)

{
    "bedroom1": {
        "temperature": 15.79,
        "humidity": 55.78,
        "battery": 5.26,
        "timestamp": "2019-02-27T22:21:37Z"
    },
    "bedroom2": {
        "temperature": 18.99,
        "humidity": 49.81,
        "battery": 5.08,
        "timestamp": "2019-02-27T22:23:44Z"
    },
    "bedroom3": {
        "temperature": 18.58,
        "humidity": 47.95,
        "battery": 5.15,
        "timestamp": "2019-02-27T22:21:22Z"
    }
}

sensor:
  - platform: rest
    name: room_sensors
    resource: http://<address_to_rest_service>
    json_attributes:
      - bedroom1
      - bedroom2
      - bedroom3
    value_template: 'OK'
  - platform: template
    sensors:
      bedroom1_temperature:
        value_template: '{{ states.sensor.room_sensors.attributes["bedroom1"]["temperature"] }}'
        device_class: temperature
        unit_of_measurement: '°C'
      bedroom1_humidity:
        value_template: '{{ states.sensor.room_sensors.attributes["bedroom1"]["humidity"] }}'
        device_class: humidity
        unit_of_measurement: '%'
      bedroom1_battery:
        value_template: '{{ states.sensor.room_sensors.attributes["bedroom1"]["battery"] }}'
        device_class: battery
        unit_of_measurement: 'V'
      bedroom2_temperature:
        value_template: '{{ states.sensor.room_sensors.attributes["bedroom2"]["temperature"] }}'
        device_class: temperature
        unit_of_measurement: '°C'