LangGraph

LangChain's graph-based agent orchestration framework (2024). Represents agent workflows as directed graphs with a centralised StateGraph managing shared state. Supports sequential chains, conditional branching, fan-out/fan-in parallelism, and iterative cycles.

LangGraph is infrastructure rather than a framework — provides routing and state management without specifying agent behaviour.

Nuclear Relevance

Limitation: Explicit state management becomes unwieldy for complex conditional flows. Concurrency supported for parallel branches but not for conversational interaction. Not designed for Pattern 9 (shared room).

Referenced in Report 6 as one of three frameworks for Level 6 multi-agent prototyping.