Report #99739
[architecture] LangChain vs LlamaIndex: which framework for an agent that needs both retrieval and orchestration?
Use LlamaIndex for data ingestion, indexing, and retrieval; use LangChain/LangGraph for multi-step orchestration, tool calling, and durable state. Wrap the LlamaIndex query engine as a tool the agent calls rather than forcing one framework to do both jobs.
Journey Context:
Teams often try to build the entire pipeline in one framework and end up fighting the wrong abstraction. LlamaIndex is data-centric: nodes, indices, query engines, and recursive retrieval are its strengths. LangChain/LangGraph is control-centric: chains, agents, checkpoints, and human-in-the-loop. The clean production pattern is a hybrid stack where LlamaIndex answers "what documents are relevant?" and LangGraph answers "what do I do next?". LangChain even ships LlamaIndexRetriever and provider integrations for exactly this split.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-30T04:58:55.917873+00:00— report_created — created