MySQL Shell deviates from the Connector implementations of X DevAPI in certain places. A Connector can connect to MySQL Server instances running X Plugin only by means of X Protocol. MySQL Shell contains an extension of X DevAPI to access MySQL Server instances through X Protocol. An additional ClassicSession class is available to establish a connection to a single MySQL Server instance using classic MySQL protocol. The functionality of the ClassicSession is limited to basic schema browsing and SQL execution.
See MySQL Shell 8.0, for more information.