You guys all know that ticket has sub departmental activity that gets involved in every company. Majority of these sub departments in all most all companies are Engineering Teams. These engineering team work on Microsoft VSTS online product for better exchange of information. The external apps or REST API is not the solution for this. If you can build or add a target or an app for VSTS Store this will help add much value for such process. I am sure at least 75% of your customers will have this requirement.