It's confusing some doc says it's deprecated but other pages explains how to see it in the web interface. If it's visible from studio.youtube.com it should be accessible from the API... right?
Q: With the API, how can I get the Unique viewer for a YouTube video?
According to the docs: The uniques metric was deprecated on September 27, 2016. It is not a core metric and will be supported until October 31, 2016.
But it is still present in the Studio Interface as described in the page of the Help Center
