Is there a REST API endpoint that returns the current volume set for the headset?

Hi Joyce, Thanks for getting in touch. Which Poly headset model are you using for this? There is some variation across the ranges, however, most of the models provide VolumeUp / VolumeDown events when those buttons are pressed on the device (via Device Event queue, HeadsetButtonPressed). This can be seen with our live demo at: https://pltdev.github.io/Plantronics%20JavaScript%20Sample.html with a wired headset, or a wireless headset with active PC audio, try adjusting the volume buttons and you should see those events reflected. However, this does not give an absolute indication of the current volume level. Similarly, with mute, you cannot query the current mute state with REST API, but you can monitor it via the Device Event queue, HeadsetStateChange (MuteOn/MuteOff) events. Note, there is more flexibility on Windows using the COM API. Hope it helps you, let me know if you have more questions. Thanks, Lewis.

Ps. You could therefore make the decision to allow the headset volume to operate separately to the softphone volume. However, 2-way mute syncronisation between softphone and headset is recommended, and is fairly easy to do by monitoring the mute state, as per the REST API sample code.