4-KT was originally a medical droid, and was one of the first droids that Riboga the Hutt sent QS-2D to set up its mining operations on Uffel. As Uffel had no use for a medical droid, 4-KT was reprogrammed for droid development, and ended up working with G-8Y5. It enjoyed its creative work, and would sometimes continue to work until it had drained its power cells.