I’d like to make my own custom integrations for my IP Camera. I’d like to enable/disable pushover notifications based on home/away status. Is this something that can be queried remotely?
You can create a SmartApp that exposes that type of information using http requests. home/away status could be Modes, or presence sensor data, either way you can get access to them.
Have you taken a look at this page yet?
It is a good starting point.
Does your camera have the capability to query an external source?