The agent pass-through is a part of the 'Connect' applet.
When configured with a URL, Exotel will pass on to that URL details of the agent who is currently being called. It makes a GET request to the URL with the following query parameters:
|CallSid||string; unique identifier of the call|
|From||string; the number of the calling party|
|DialWhomNumber||string, the number of the agent|
|Status||busy/free. This is sent as 'busy' when the above agent is being called. It is sent as 'free' when the call to the above agent ends (either the call ends, or the call didn't go through, or the agent didn't pick up the phone).|