LlamaIndex

LlamaIndex is an open-source data framework for building LLM applications, with a particular focus on connecting AI systems to private, domain-specific data. LlamaIndex provides tools for data ingestion, indexing, retrieval-augmented generation (RAG), and building agentic data workflows.

While LangChain focuses broadly on LLM application orchestration, LlamaIndex specializes in the data connectivity challenge: parsing unstructured documents, building efficient vector indexes, implementing advanced retrieval strategies, and creating data agents that can query multiple data sources. LlamaIndex also provides LlamaParse for document parsing and LlamaCloud for managed RAG infrastructure.

In the agent orchestration layer, LlamaIndex is essential infrastructure for grounding AI agents in real-world data — ensuring that agents can access, understand, and reason over an organization's specific knowledge.