Sentence Transformers

Framework for generating text embeddings locally without hitting paid APIs. Gives you access to 5000+ pre-trained models from Hugging Face, including solid general-purpose options like all-MiniLM-L6-v2 for fast prototyping and all-mpnet-base-v2 for production RAG systems. Supports 100+ languages and works with LangChain and LlamaIndex out of the box. The quality won't match OpenAI's latest embeddings, but you can fine-tune models for your domain and the cost savings are real if you're processing volume. Built on PyTorch, so GPU acceleration makes batch encoding reasonably fast.