Select multiple entities to link their on/off state. If any selected entity is turned on or off, the other selected entities will be sent a matching on or off command.

link_multiple_devices.yaml

blueprint:
  name: Link On/Off State of Multiple Devices
  description: |
    ## Link On/Off State of Multiple Devices v1.0.2

    Select multiple entities to link their on/off state.  If any selected entity is turned on or off, the other selected entities will be sent a matching on or off command.

    You can select any entity, but only entities supported by the `homeassistant.turn_on` or `homeassistant.turn_off` action calls will work.

    Use The Time Options (Optional)

    ### Requirements
    * All selected entities MUST suport `homeassistant.turn_on` and `homeassistant.turn_off` or errors will be logged and the blueprint will not work.
    * Requires Home Assistant 2024.10.0 or newer.

    ### Credits
    * [@adchevrier](https://community.home-assistant.io/u/adchevrier) for the [initial blueprint](https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010)
    * [@hebus](https://community.home-assistant.io/u/hebus) for [this fantastic template](https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010/38)
  domain: automation
  homeassistant:
    min_version: 2024.10.0
  input:
    linked_entities:
      name: Entities to link
      selector:
        entity:
          multiple: true

    time_settings:
      name: Time
      icon: mdi:clock-outline
      collapsed: true
      input:
        include_time:
          name: Use The Time Options (Optional)
          default: time_disabled
          selector:
            select:
              options:
                - label: Enable the time options
                  value: time_enabled
                - label: Disable the time options
                  value: time_disabled
        after_time:
          name: Start Time
          description: >
            Set the start time.
          default: 00:00:00
          selector:
            time:
        before_time:
          name: End Time
          description: >
            Set the end time.
          default: 00:00:00
          selector:
            time:
        weekday_options:
          name: Weekdays
          description: >
            Select the days of the week you would like the automation to run.
            You must select "Enable the time options" above for the weekday selections to work.
          default:
            - mon
            - tue
            - wed
            - thu
            - fri
            - sat
            - sun
          selector:
            select:
              multiple: true
              mode: list
              options:
                - label: Monday
                  value: mon
                - label: Tuesday
                  value: tue
                - label: Wednesday
                  value: wed
                - label: Thursday
                  value: thu
                - label: Friday
                  value: fri
                - label: Saturday
                  value: sat
                - label: Sunday
                  value: sun

mode: restart
max_exceeded: silent

variables:
  linked_entities: !input linked_entities
  include_time: !input include_time
  after_time: !input after_time
  before_time: !input before_time
  weekday_options: !input weekday_options

triggers:
  - trigger: state
    entity_id: !input linked_entities
    from:
      - 'on'
      - 'off'
    to:
      - 'off'
      - 'on'

conditions:
  - condition: or
    conditions:
      - condition: template
        value_template: "{{ include_time == 'time_disabled' }}"
      - condition: and
        conditions:
          - condition: template
            value_template: "{{ include_time == 'time_enabled' }}"
          - condition: time
            after: !input after_time
            before: !input before_time
            weekday: !input weekday_options
  - condition: template
    value_template: "{{ trigger.to_state.state != trigger.from_state.state }}"
  - condition: template
    value_template: "{{ (trigger.to_state.state == 'on') or (trigger.to_state.state == 'off') }}"
  - condition: template
    value_template: >-
      {{
        trigger.to_state.context.parent_id is none or
        (
          trigger.to_state.context.id != this.context.id and
          trigger.to_state.context.id != this.context.parent_id and
          trigger.to_state.context.parent_id != this.context.parent_id
        ) or
        (
          trigger.to_state.context.id == this.context.id and
          trigger.to_state.context.id == trigger.from_state.context.id and
          trigger.to_state.context.parent_id == this.context.parent_id and
          trigger.to_state.context.parent_id == trigger.from_state.context.parent_id
        ) or
        (
          trigger.to_state.context.id == this.context.parent_id and
          trigger.to_state.context.id == trigger.from_state.context.id and
          trigger.to_state.context.parent_id == trigger.from_state.context.parent_id
        )
      }}

actions:
- action: homeassistant.turn_{{ trigger.to_state.state }}
  target:
    entity_id: >-
      {{ expand(linked_entities) | selectattr('entity_id', '!=', trigger.entity_id) | map(attribute='entity_id') | list }}