What is the right way to specify an entity in an action?

Configuration
1

This is not an important question, so please answer all the other questions from all the other people first. :wink:

I’m reorganizing some Home Assistant automations and I wasn’t sure how to specify the entity. I did some testing and I found that all of these work perfectly fine!

Variant 1: On action root

action:
  - service: climate.set_hvac_mode
    entity_id: climate.th_office
    data:
      hvac_mode: "auto"

Variant 2: Nested under target

action:
  - service: climate.set_hvac_mode
    target:
      entity_id: climate.th_office
    data:
      hvac_mode: "auto"

Variant 3: Nested under data

action:
  - service: climate.set_hvac_mode
    data:
      hvac_mode: "auto"
      entity_id: climate.th_office

So my questions are:

  1. Which variant is the most idiomatic?
  2. Why do all of these work?
  3. Is there a reason to prefer one over the others?
1 Like
2

I think Petro (mod) once gave quite a complete answer, but I can’t find it now. Maybe he sees this and chimes in.

Basically: Legacy.

Slightly longer answer: It evolved a bit over time, so there are a number of variants, depending, as you’ve observed.

I can’t speak for each and every service call and integration, but generally speaking your entity ID is the target and the rest is just additional data, like passing parameters to a function (if you’re familiar with programming).