Cody is a member of the Reckoners and does many different jobs for them. He speaks with a southern accent, but insists he is Scottish. Out of all the Reckoners, including David, Cody seems to be the most easily trusting, as shown when he was immediately one of the kindest people towards David and spills some insight on the team members, like Megan's cold exterior.
Even in the third book, Calamity, this trusting side of his is not diminished when he's forced to work with Megan again. Though she was known to have been an Epic who was fooling them all at some point, Cody doesn't hold a grudge against her for this. In fact, he is shown to have a lot of trust in Megan despite the whole fiasco because she was already proving herself to be on their side.
Cody has this belief that the present is what truly matters. It doesn't matter why he or any one of the others are fighting against Epics. What matters is that they're all on the same side.
Cody is a very good shot, and sometimes acts as a sniper. He also works odd jobs for the Reckoners, such as driving, hauling, etc.
Though his words are often dismissed by the majority of his team members, the team does very much trust him. He uses this trust to his advantage as shown in the first book when everyone had their doubts about David's (SPOILERS FOR STEELHEART) plan to imitate Limelight as a way to lure out Steelheart. Cody is the one to lay down the pros of David's plan, which is what initiated it in the first place.
He often speaks of his 'acomplishments,' often mixed with Scot stories.