What problem does it solve? Training and fine-tuning large language models typically requires navigating complex abstraction layers and fragmented tooling. This Skill provides clean, single-file LLM implementations with production-ready workflows for downloading, fine-tuning, pretraining, quantizing, and deploying 20+ model architectures. ## Core Features & Use Cases - Fine-tuning with LoRA/QLoRA: Train models like Phi-2 or Llama 3 on custom JSON datasets using parameter-efficient methods that fit on consumer GPUs (8-16GB VRAM). - Pretraining and distributed training: Pretrain models from scratch with multi-GPU FSDP support and proven hyperparameter recipes. - Model deployment: Merge LoRA adapters, quantize to 4-bit, convert to GGUF, and serve models via a FastAPI endpoint. - Use Case: Fine-tune Phi-2 with LoRA on a custom Alpaca-format instruction dataset using a single 16GB GPU, then merge the adapters and deploy the model behind a REST API. ## Quick Start Use the LitGPT skill to fine-tune microsoft/phi-2 with LoRA on my custom instruction dataset and show me the training command.