This repository is an educational collection of minimal, from-scratch implementations of core LLM and generative AI systems, maintained by DataWhale. It is not a single production application; rather, it is a set of self-contained 'Tiny' sub-projects covering a small LLM trained on TinyStories, a RAG pipeline, a ReAct agent, an LLM evaluation harness, a DDPM diffusion model, a Transformer, a GraphRAG system, and an image-based RAG pipeline. Each sub-project has its own README, requirements, and runnable code or notebooks, with heavy Chinese-language comments explaining the underlying theory. The code is intentionally simple and readable rather than production-hardened, and it serves as a teaching resource for understanding how these systems work internally.