langgraph-error-handling

| Transient | System | RetryPolicy | | LLM-recoverable | LLM | State update + Command(goto=...) | | User-fixable | Human | interrupt() + Command(resume=...) | | Unexpected | Developer | Raise/log/debug |

Use custom handlers when you need deterministic error shaping for model recovery. For broader tool-recovery design, load references/llm-recovery.md.

| interrupt() fails at runtime | no checkpointer | compile with checkpointer | | Resume starts new run | different threadid | reuse same threadid | | JS Command route not taken | missing ends | add ends to addNode | | Infinite loop | no termination counter/condition | add retry counter + terminal branch |

使用目前 v1 模式實作 LangGraph 錯誤處理。当用户需要对故障进行分类、为暂时性问题添加 RetryPolicy、使用命令路由构建 LLM 恢复循环、使用中断（）/恢复添加人机交互、处理 ToolNode 错误或在重试、恢复和升级之间选择安全策略时使用。 來源：lubu-labs/langchain-agent-skills。