OpenHAB with pfSense for phone presence detection

There are various threads about how to detect phones on the local network to know if a user is present. Has anyone explored creating a package for pfSense (open source router) that would look at the ARP table to the presence of the device?
The idea comes from doing this same thing on WDDRT (

This seems related…

I’ve also a Python script that looks for ARP packets for a given MAC (it was an attempt to do something with Amazon Dash buttons). However, I don’t know if all phones always send an ARP packet when they initially join a network. And of course it doesn’t help with detecting when the device leaves the network.

I did a quick Google search and found a blog posting that states there will be a REST API in pfSense 3.0. With that the HTTP binding might work.

Thanks for the inf about the REST API in 3. I was unaware of it.