This chapter will provide an architectural and functional overview of Oracle API Catalog (OAC). It will discuss the different components and layers that build up the product architecture and then provide a short overview of the product functionality. Subsequently, an implementation use case is described which is then followed up by a series of hands-on and step-by-step recipes that illustrate how to implement the product to address the use case requirements. The chapter covers both simple recipes and also more complex ones, showing for example how to configure and use the Ant Harvester and also how to consume the REX API to extend OAC functionality.