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