A while ago I wrote a tutorial on how to use the old style Project Server Interfaces (PSI) with Project Online. In the meantime the Project Online team deprecated a few PSI interfaces, but some others are still available.
The attached sample code reflects those changes and provides a Project Online client context enhanced with the available PSIs in Project Server 2016. Note that some of these will probably be deprecated in the future, so if you’re getting weird communication fault errors it’s likely the case. The sample itself calls into the PWA PSI and enumerates the list of projects.
Download the Project Online PSI Sample (updated) sample and please leave a comment.