Combining Temporal and LangGraph creates a deceptively simple question: which runtime owns the state of the agent? Both preserve execution progress, but they preserve different kinds of progress. Temporal reconstructs Workflow state from Event History and reuses recorded Activity results during replay. LangGraph persists thread-scoped graph state as checkpoints and resumes from super-step boundaries. Treating those mechanisms as interchangeable creates ambiguous recovery semantics. Production integration therefore needs explicit authority for business progress, agent working state, and the handoff between them. Deployment language, storage backend, model provider, and hosting topology remain unspecified assumptions. The current Temporal LangGraph integration narrows the problem. Its public-preview Python plugin can run LangGraph nodes as Temporal Activities or deterministic Workflow code, while Temporal provides durability; the documentation recommends an in-memory LangGraph checkpointer rather than a separate PostgreSQL or Redis checkpointer. Continue-As-New can carry cached task results into the next Workflow Run.