Thanks for your reply. I’m sure I’m missing something, but in the scenario of a temperature sensor, wouldn’t that info already be available in the temperature entity’s state.

So you could already write a script like this one:

service: climate.set_fan_mode
data:
  fan_mode: >
    {% if states(‘sensor.temperature’) > 40 %} 5
    {% elif 30 > states(‘sensor.temperature’) > 40 %} 4
    {% else %}  3
    {% endif %}
target:
  entity_id: climate.bedroom_thermostat

But again, I’m probably missing something.

Thinking about the calendar service they added, maybe the response is useful for returning multiple pieces of data.

Perhaps a use case is return a history of the previous states, so in your example, you could have a history service that could give you historical values from the temperature sensor. You call asking is the temperature trending up or down, it checks the history and provides a response. Then again, maybe you can already do that with derivative sensors.

Sorry for the scattered response, I feel like I’m on the verge of understanding the feature, but not quite there yet.