Please read this article for full discussion about using the supervision API.

@Phong Vu - Thank you for that awesome article. Its very helpful. To test some very very basic functionality, can you advise, if by using postman,

1) Can we display all available active sessions

2)

our users use the RC integration into Salesforce to make and receive calls on their Ipad/mobile devices. Does the below statement mean that, it is not possible to supervise as its a mobile device. (trying to understand between softphone and app integrated into the mobile app)

"Currently this method is supported for Softphone/Hardphone only, since device IDs for WebRTC/Mobile apps cannot be obtained."

Thank you.

I don't know what you can do in real-time using PostMan. You should choose a programming language and implement your app as close as possible to your final app.

But if you want to list user active calls to get the tel session id, call this API.

"Currently this method is supported for Softphone/Hardphone only, since device IDs for WebRTC/Mobile apps cannot be obtained."

The statement above means the phone/device that you can use to listen/monitor a call, NOT the phone/software that the call parties are using to make a call. The reason behind that is the supervise API requires a device id to identify the device/phone that the audio is routed to.