Since the base module (mcp) can provide the basic functionality for:

• creating a STDIO-based server and client
• creating a JDK HttpClient-based SSE client
• creating a Servlet-based SSE server

It would probably be a good idea to not have framework-specific transport implementations inside the java-sdk.

In the case of mcp-spring-* modules, they would be moved to the spring-ai project and can be used as part of the Spring AI integration with the MCP Java SDK. The question remains whether there are existing users of these modules that do not rely on Spring AI itself. If there are, their input can be used to consider publishing these modules as independent artifacts as they currently are but under a different group.

Inside the mcp core module we can focus on providing the core protocol implementation and maintain these basic transport implementations. While they are quite verbose and require a lot of ceremony, they can provide the minimal set of functionalities to allow users to be framework-agnostic if they so choose.