The customKernel module also provides a session.customData object that allows you to store data on the session object and query it from the GUI. Data stored on the session object persist only for the current Abaqus/CAE session. When you close the Abaqus/CAE session, Abaqus does not store any of the data below session.customData on the model database. As a result, these data will be lost, and you will not be able to retrieve these data when you start a new session and open the model database. The session object is useful for maintaining data relevant to the current session only, such as the current model or output database.
The same methods and classes that are available for mdb.customData are available for session.customData.