Beliefs-Desires-Intentions models (or BDI models) of agents have been around for quit a long time. The purpose of these models is to characterize agents using anthropomorphic notions, such as mental states and actions. However, despite the fact that many systems have been developed based on these models, it is a general concern that there is a gap between those powerful BDI logics and practical systems. The purpose of this paper is to present a BDI model that, besides being a formal model of agents, is also suitable to be used to implement agents. Instead of defining a new BDI logic or choosing an existing one, and extending it with an operational model, we define the notions of belief, desires and intentions using a logic formalism that is both well-defined and computational.