Using a ZD is there an API or method to get a set of data (outside of the web interface) of currently connected devices and information about how and where they are connected?
For example a xml file containing client_mac, ap_mac and rssi for each device?
There are SNMP calls that will tell you where each client is associated.
note: you cannot get information on rssi from a client to a nearby non-associated AP.
(at least not easily)
... making triangulation nearly impossible.
note: the available "RSSI" information is often misleading.