sorry! I don't know.
Login with chess.com possible?

you can always redirect "To" chess.com but after getting the OAuth there is no API to send them back to your site. Also, they don't have OAuth tokens. The only way would be getting permissions and I don't think its realistic since it would open the vector to attack via a hacker
I would like to be able to use chess.com as an auth system for my site. Is it possible to redirect users to chess.com to authenticate?