Headless Server uses the Spring-GraphQL library to invoke GraphQL queries that are received via HTTP requests. Spring-GraphQL operates on Springs functional web framework. At the beginning of an invocation chain stands a RouterFunction which declares its responsibility for a certain path and eventually restricts to specific HTTP methods. If the RouterFunction takes an incoming request, it delegates the further handling to a handler class. To process GraphQL queries a special GraphQLHandler is necessary. GraphQLHandler is an implementation by Spring-GraphQL and handles the runtime aspects of a query invocation.

Headless-Server comes with its own GraphQL handler which subclasses the original GraphQLHandler. THe handler extends the original abilities by allowing also HTTP-Get requests to send GraphQL queries and enabling persisted queries via HTTP-Get.