Are you working on a client SDK with access to the media stack? Similar to Skype client functionality. Either from a Tab app or external to teams client. ISV can make the teams client react to caller number or sipaddress with customer specific information or routing/(auto)answering the call.
I too am very keen to know how to achieve this with the current/new API's for Teams.
So far, it seems as though you can only get *minimal* event notification, if you develop a "Bot".
We would need/want to receive notifications of any incoming/outgoing telephone calls (along with the CLI/ANI). However, it seems the current API's are not friendly to external application/services connecting on a per-user, basis?
Would very much welcome any guidance on this, thanks!