llamaindex
LlamaIndex is a data framework designed to connect large language models (LLMs) with external data sources for context-aware responses.
It enables retrieval-augmented generation (RAG) by indexing documents, databases, APIs, and other content, then querying them with natural language.
Originally called GPT Index, LlamaIndex structures data into nodes, builds efficient vector stores or keyword indexes, and supports custom retrieval pipelines.
It integrates with LLMs like OpenAI, Anthropic, and open-source models, making it easy to build chatbots, agents, and search interfaces over private or domain-specific data.
It supports Python, offers modular architecture, and complements frameworks like LangChain and Semantic Kernel.