Karpathy's $100 full-stack ChatGPT clone
Andrej Karpathy just dropped nanochat, an 8,000-line codebase that packs an entire end-to-end ChatGPT training and inference pipeline into a single repo. Running a single script on an 8xH100 node costs about $100 and yields a working, chat-ready model in just four hours, covering everything from tokenizer training to GRPO reinforcement learning. Why it matters: It turns the entire modern LLM post-training playbook into a readable, easily forkable playground for developers.