Sync Volume between two Media Players

volume-state-sync.yaml

blueprint:
  name: Synchronize Audio Volume
  description: Synchronize the volume of 2 entities
  domain: automation
  input:
    entity_1:
      name: First entity
      selector:
        entity: {}
    entity_2:
      name: Second entity
      selector:
        entity: {}
  source_url: https://gist.github.com/creedda/a346d0c1ef3a883caeb7207e83ecf58c
mode: restart
max_exceeded: silent
variables:
  entity_1: !input entity_1
  entity_2: !input entity_2
trigger:
- platform: state
  entity_id: !input entity_1
- platform: state
  entity_id: !input entity_1
  attribute: is_volume_muted
- platform: state
  entity_id: !input entity_1
  attribute: volume_level
- platform: state
  entity_id: !input entity_2
- platform: state
  entity_id: !input entity_2
  attribute: is_volume_muted
- platform: state
  entity_id: !input entity_2
  attribute: volume_level
condition: []
action:
- choose:
    - conditions:
        condition: template
        value_template: "{{ is_state(trigger.to_state.entity_id, 'on') }}"
      sequence:
        
        - service: media_player.volume_set
          data:
            volume_level: '{{ state_attr(trigger.to_state.entity_id, "volume_level") }}'
            entity_id: '{% if trigger.from_state.entity_id == entity_1 %} {{ entity_2 }} {% else %} {{ entity_1 }} {% endif %}'
        
        - service: media_player.volume_mute
          data:
            is_volume_muted: '{{ state_attr(trigger.to_state.entity_id, "is_volume_muted") }}'
            entity_id: '{% if trigger.from_state.entity_id == entity_1 %} {{ entity_2 }} {% else %} {{ entity_1 }} {% endif %}'
  default: