An agent’s knowledge of her own intentional actions (agential knowledge) is non-observational. Yet, intentional actions typically consist of happenings external to the agents. A theory is needed to explain how agents are warranted to form such beliefs independent of observation. This chapter first argues for three desirable features of an ideal theory about agential knowledge. After showing that no existing theories possess all three, a novel theory that does is presented. According to this theory, agential knowledge is the same kind of knowledge as the Kripkean contingent a priori: they are knowledge justified a priori by stipulation.