TA-1313 was a T-series tactical droid that fought for the Confederacy of Independent Systems during the Clone Wars, serving under Count Dooku.
In the early days of the Battle of Ryloth, TA-1313 intercepted an encrypted Republic message. After decoding it, he learned that the Jedi had asked Senator Bail Prestor Organa to go to Toydaria. Organa's mission was to negotiate with King Katuunko for permission to use the planet as a supply route for the oppressed people of Ryloth.
After gaining this information, he told Count Dooku. Dooku then instructed the tactical droid to contact senator Lott Dod of the Trade Federation so that he could address the situation on behalf of the Confederacy.
Originally, TA-1313 was thought to be TX-20 in the episode Supply Lines, because that name appeared in the closing credits. However, later in 2012, the online game Star Wars: Clone Wars Adventures added an expansion to its card game "Card Assault," which featured a card depicting this droid and identifying it as TA-1313. It seems the two tactical droids were intended to be different characters. TA-1313 looks more like the T-series tactical droid on Kiros from Kidnapped than TX-20, though it is not confirmed if they are the same droid.