What problem does it solve? Training and fine-tuning large language models typically involves navigating complex abstraction layers and fragmented tooling. This Skill provides clean, single-file LLM implementations with production-ready training workflows, making it straightforward to fine-tune, pretrain, quantize, and deploy models like Llama, Gemma, Phi, Qwen, and Mistral. ## Core Features & Use Cases - Fine-tuning with LoRA/QLoRA: Train adapters on consumer GPUs (12-16GB VRAM) using configurable rank, alpha, and dropout parameters, then merge weights for deployment. - Pretraining and distributed training: Pretrain models from scratch with multi-GPU FSDP sharding, mixed precision, and gradient accumulation across nodes. - Model conversion and deployment: Quantize checkpoints to 4-bit, convert to GGUF for llama.cpp, and serve models through a FastAPI endpoint. - Use Case: Fine-tune Phi-2 with LoRA on a custom Alpaca-format JSON dataset using a single 16GB GPU, merge the adapter weights, and deploy the merged model behind an inference API. ## Quick Start Ask the AI to fine-tune microsoft/phi-2 with LoRA on your instruction dataset using LitGPT and show the training command.