This module contains the actual app that runs the Airbyte Configuration API. The main method can be found in ServerApp.java.
The external API interface that it implements is declared in airbyte-api. The class that actually implements that interface is called ConfigurationApi. You will notice that class is very large, because generates a method for every endpoint. To keep it manageable, that class just delegates all requests to more tightly-scoped, resource-based handlers. For example, the workspace/get endpoint is present in ConfigurationApi, but all it does it delegate the call to the WorkspaceHandler which contains all Workspace-specific logic. Unit tests for the server happen at the Handler-level, not for the ConfigurationApi.