The Tech Citadel, situated on the planet Coruscant, was a complex where slicers and technicians worked for the Galactic Republic. In the era of the Clone Wars, at the behest of the Jedi Order, the Citadel's slicers scrutinized the memory banks of the protocol droid TD-54. This analysis revealed that the droid possessed a full suite of control instructions for a battle droid factory located on Geonosis, and that he was previously under the ownership of the crime lord Jabba the Hutt.
The initial reference to the Tech Citadel appeared within the Twilight of the Republic play set featured in Disney Infinity 3.0, a non-canonical video game released in 2015.