C4-ZX functioned as a protocol droid during the era of the Galactic Civil War, operating sometime after the point of 0 BBY. Ji'Ni Sil, a Jawa trader, was the owner of this particular droid. This droid was present alongside its master at the Jawa Mountain Fortress situated on the planet of Tatooine. In the year 1 ABY, a spacer approached Ji'Ni Sil, expressing interest in acquiring a body casing that had once belonged to an R2 unit previously owned by Peggin Dulin. Both Imperial Commander Barrezz and Rebel Captain Bastra were actually seeking this very droid. C4-ZX revealed to the spacer that the droid casing had already been sold to a robonium miner. Even though Tusken Raiders had killed the miner, the spacer ultimately succeeded in obtaining the casing.
Within the 2003 video game Star Wars Galaxies, C4-ZX appeared as a non-player character. This massively multiplayer online roleplaying game was developed by Sony Online Entertainment and published by LucasArts. The game was shut down on December 15, 2011. C4-ZX's inclusion in the game occurred as a component of the "Legacy Quest" with the release of "Publish 25," which is also known as the "New Game Enhancements," on November 15, 2005.