An online addition to The Essential Atlas, titled Essential Atlas Extra: The Knight Errant Gazetteer, was written by Daniel Wallace, Jason Fry, and John Jackson Miller. It was released on StarWars.com on November 12, 2012. This supplement is connected to the Knight Errant comic book series and presents the historical background and mapping of the Grumani sector. A significant portion of the content is structured as a communication from Jedi Master Vannar Treece directed towards Supreme Chancellor Genarra.