JS-25 was a protocol droid that dwelled in the droid-run settlement X2-4 on the moon Uffel during the latter years of the Galactic Republic. JS-25 had computer-repair capabilities and after Uffel's MSF mouse droid production line was sabotaged by the rogue droid LN-73 in about 31 BBY, JS-25 and fellow protocol droid Y-2D0 were sent to re-program the production line's systems.