As APIs are becoming popular to build Service-Based Applications (SBA), API Gateways are being increasingly used to facilitate API features management. They offer API management functionalities such as pricing plans support, user authentication, API versioning or response caching. Some parts of the information that an API Gateway needs are already included into a Service Level Agreement (SLA), that providers use to describe the rights and the obligations of involved parties in the service. Unfortunately, current API Gateways do not use any SLA representation model nor SLA underlying technology, thereby missing potential opportunities. In this paper we analyze the state of the art to justify the current situation and we identify some research challenges so as to achieve SLA-Driven API Gateways.