LlamaIndex started as a library for indexing documents so an LLM could answer questions about them. "LlamaIndex equals RAG" was a fair summary for years. It no longer is. ........ LlamaIndex is an open-source, provider-agnostic Python framework for building LLM applications over a team's own data — loading, chunking, embedding, retrieving, and orchestrating the logic around that retrieval. As of 2026 it's organized around Workflows, an event-driven way of composing multi-step