Modular Protocol Stack Architecture separates client and server concerns into distinct library layers with pluggable extensions and codec/transport abstractions. Client and Server Programs interact through their respective libraries, which delegate to shared Helper Libraries for codec and transport operations. This layered design enables independent evolution of protocol components, codec implementations, and transport mechanisms without coupling application logic to infrastructure details. Fork this diagram on Diagrams.so to customize extension points, add new codec variants, or document your protocol stack's modular boundaries. The architecture exemplifies separation of concerns and plugin-based extensibility patterns critical for maintainable, scalable protocol implementations.