Apache Airavata is software for providing services to manage scientific applications on a wide range of remote computing resources. Airavata can be used by both individual scientists to run scientific workflows as well as communities of scientists through Web browser interfaces. It is a challenge to bring all of Airavata’s capabilities together in the single API layer that is our prerequisite for a 1.0 release. To support our diverse use cases, we have developed a rich data model and messaging format that we need to expose to client developers using many programming languages. We do not believe this is a good match for REST style services. In this presentation, we present our use and evaluation of Apache Thrift as an interface and data model definition tool, its use internally in Airavata, and its use to deliver and distribute client development kits.