Is there a supported REST API exposed by V15? I know I can use the Windows client app to initiate a call and I can use the Visual Studio template to extend the client. But suppose I create collaboration app for Android and I want to provide a button a user can press to initiate a VoIP call with one of our representatives or with other collaborators with internal extensions. I could include a SIP/RTC stack and initiate a call. But I'm wondering if this type of functionality is covered in a documented API. Or maybe I want to allow the user of an extension the ability to enable/disable options relating to their account from their Android phone in the context of an application. I think I may be able to open Chrome session for the user and direct them to our 3CX implementation when they login, find the option can, hopefully, change it. But that's a lot of effort for a user to, say, enable call recording or disable voicemail. I feel like there's some API documentation I've not found yet.