A customer sends a boot photo, asks for a waterproof alternative, then asks about returns. Vision analysis, product search, and policy retrieval each contribute to the answer. State management keeps their work available across the workflow so the final response does not lose or garble a result. section 8.0 section 8.1.7
In LangGraph, state is a shared data structure that agents and processing steps can read and write. Nodes perform the work; edges connect the steps; conditional edges choose a route using state or agent output. The orchestrator can therefore invoke the agents a request needs while preserving information between steps. section 8.1.2 section 8.4
Keep state management tied to the whole response, not just an individual agent:
- Preserve each agent’s contribution for synthesis, whether the request needs search, policy Q&A, vision, or a combination. section 8.1.7
- Test blended queries, ambiguous intent, agent failures, and state continuity. A correct agent result is not enough if coordination drops it. section 8.4
- For production agents, consider LangGraph state management when checkpointing, approval steps, or memory across sessions are needed; standalone LangChain memory classes remain useful for simpler applications. section 6.2.2
