Hornet (formerly TOA) layers on top of Core X and provide a very lightweight service modeling mechanism appropriate for Topic Oriented Message Type based Routing.. Unlike Eagle service definitions, Hornet service definitions map message types to topics allowing for a rich topic namespace and allow for more complex interaction models. Hornet is well suited to high performance applications that are event basedis an extension to Talon and is intended for applications that are run using a rich topic namespace on a publish-subscribe based messaging fabric. Hornet provides a lightweight mechanism to declaratively define the various topics that exist on the fabric, declare micro app interest in the topics and map messages types to topics. In doing so, Hornet enables micro apps to use topics to drive complex inter-app routing and work exclusively with message types are the application layer.