Converting part of path to a string I can work with?

I’m using an alarm system (alarmo) in home assistant which reports which sensor caused the alarm to go off.
I’ve highlighted here in yellow where I can find the sensor.

image

So the key data I need is stored as an object in data.new_state.attributes.open_sensors and looks like this:
{“binary_sensor.inkom_pir_alarm”:“open”}

I obviously know how to get “open” and work with that. The problem is that the value I need is before the “:” and is part of what I guess I should call the path.
I’ve searched for hours how to get to this, but couldn’t find anything.

Could anybody give me a hint please?
Many thanks

With jsonata, you should be able to do what you want:

$keys(data.new_state.attributes.open_sensors)

Will give you all open_sensors. I assume there may be more than one…

excellent, this is precisely what I needed.
I need this also when arming failed and in that case you are right that there can be more than one sensor (eg windows that are open) that prevented arming.
Thanks to your help I now get a notification of my phone with which sensor triggered the alarm, or which sensors prevented the alarm from arming.
Thanks a lot!