Global Variables in Home Assistant

1.Great for triggers, conditions, and actions

2.When the automation ends, the variable disappears (not persisted).

1.use a Trigger-based Template Sensor detail1

2.config/custom_templates.detail

json file

1.use templating json

use custom integration

https://github.com/rogro82/hass-variables

action:
  - service: variable.set_variable
    data:
      variable: last_motion
      value: "livingroom"
      attributes_template: >
        {
          "history_1": "{{ variable.state }}",
          "history_2": "{{ variable.attributes.history_1 }}",
          "history_3": "{{ variable.attributes.history_2 }}"
        }

post

http://homeassistant.local:8123/api/states/:entity_id

{
    "state": "below_horizon",
    "attributes": {
        "next_rising":"2016-05-31T03:39:14+00:00",
        "next_setting":"2016-05-31T19:16:42+00:00"
    }
}

/data/homeassistant202405/custom_template/stations.jinja

{% macro stations_data() %}
[
    {
      "name": "Station One",
      "url": "https://one.example.com",
      "inital_volume": 120
    },
    {
      "name": "Radio two",
      "url": "https://two.example.com",
      "inital_volume": 100
    },
    {
      "name": "LiveTalk",
      "url": "https://three.example.com",
      "inital_volume": 110
    }
  ]
{% endmacro %}

json file

1.use templating json

import json

# Read from file and parse JSON
with open("sample.json", "r") as f:
    data = json.load(f)

print(data)
print(type(data))

import json
data = {
    "name": "sathiyajith",
    "rollno": 56,
    "cgpa": 8.6,
    "phone": "9976770500"
}

with open("sample.json", "w") as f:
    json.dump(data, f)

This integration can expose regular REST commands as actions. Actions can be called from a script or in automation

detail

2.detail

template:
  - binary_sensor:
      - name: "Chinese Holiday Today"
        state: >
          {% set file = '/config/data/holiday-cn-2025.json' %}
          {% set data = read_file(file) | from_json %}
          {% set today = now().strftime('%Y-%m-%d') %}
          {% set holiday = data | selectattr('date', 'equalto', today) | list %}
          {{ holiday | count > 0 }}
        attributes:
          friendly_name: "Is today a Chinese holiday?"

json file +restful api template sensor in configuration.yaml

https://www.home-assistant.io/integrations/sensor.rest/

post

http://homeassistant.local:8123/api/states/:entity_id

{
    "state": "below_horizon",
    "attributes": {
        "next_rising":"2016-05-31T03:39:14+00:00",
        "next_setting":"2016-05-31T19:16:42+00:00"
    }
}

http json+rest_command

rest_command:
  secured_command:
    url: "http://example.com/api/secure-endpoint"
    method: post
    authentication: digest
    username: "your_username"
    password: "your_password"
    payload: '{"data": "example"}'
    content_type: "application/json"

1.detail

2.detail

command_line:
  - sensor:
      name: JSON user
      command: python3 -c "import requests; print(requests.get('https://jsonplaceholder.typicode.com/users').text)"
      json_attributes_path: "$.[0].address"
      json_attributes:
        - street
        - suite
        - city
        - zipcode
      value_template: "{{ value_json[0].name }}"