In V2 you could hit the /api/users/default
path to get infomation such as the user\'s username. This is documented here: https://developers.google.com/youtube/2
In v3, user info is basically channel info. By doing a channels->list "https://developers.google.com/youtube/v3/docs/channels/list", you will get the information under 'snippet.channelId' "https://developers.google.com/youtube/v3/docs/channels#snippet.channelId"
Youtube API v3 does not support user information any more. Use userinfo API.
set scope: https://www.googleapis.com/auth/youtube.force-ssl
https://www.googleapis.com/auth/userinfo.profile
(a space between scopes)
and get: https://www.googleapis.com/oauth2/v1/userinfo?access_token={access_token}