ds4.c is a small native inference engine for DeepSeek V4 Flash. It is intentionally narrow: not a generic GGUF runner, not a wrapper around another runtime, and not a framework. The main path is a DeepSeek V4 Flash-specific Metal graph executor with DS4-specific loading, prompt rendering, KV state, and server API glue. This project would not exist without llama.cpp and GGML, make sure to read the