Sente can automatically import Mendeley libraries.
If you have a Mendeley library on your computer, when you use the File > New Library command, that library should be listed as an option in the dialog window that appears. If you select that option, Sente will automatically import all of the references and attachments from your Mendeley library into your new Sente library.
If for some reason your Mendeley library is not listed in the New Library dialog, you can use the File > Import Reference Data command and select the library manually in the file chooser that appears.
For additional information on this topic, please see the chapter entitled Migrating Data from Other Applications in the Sente User Manual.