nanochat LLM Training Skill by ara.so — Daily 2026 Skills collection. nanochat is Karpathy's minimal, hackable harness for training LLMs end-to-end on a single GPU node. It covers tokenization, pretraining, SFT finetuning, RL, evaluation (DCLM CORE score), inference with KV cache, and a ChatGPT-like web UI. A single complexity dial ( ) auto-configures all other hyperparameters (width, heads, LR, training horizon, weight decay) for compute-optimal training. You can reproduce GPT-2 capability ( $43,000 in 2019) for $48 on an 8×H100 node ( 2 hours). Installation nanochat uses for dependency mana…