# LangGraph LangGraph is a low-level orchestration framework built on top of [[LangChain]] for building stateful, long-running [[AI Agents]]. While LangChain creates [[Directed Acyclic Graphs (DAG)]] for linear workflows, LangGraph enables cyclic computational graphs; essential for complex agent behaviors where LLMs continuously loop and dynamically decide actions based on evolving conditions. Version 1.0 was released in November 2025. ## Key Features - **Stateful execution**: Maintain and modify agent state throughout interactions - **Durable execution**: Agents persist through failures and resume from checkpoints - **Cyclic graphs**: Support loops and conditional branching (unlike DAG-only frameworks) - **Human-in-the-loop**: Inspect and modify agent state at any point - **Memory systems**: Both short-term working memory and long-term cross-session memory - **Concurrent users**: Manage independent graph instances per user at scale ## When to Use LangGraph vs LangChain | Scenario | Framework | |----------|-----------| | Simple, linear workflows | [[LangChain]] | | Document Q&A systems | [[LangChain]] | | Complex multi-step agents | LangGraph | | Long-running autonomous tasks | LangGraph | | State-dependent decision making | LangGraph | | Production-scale agent deployments | LangGraph | ## Architecture LangGraph models agents as state machines with: - **Nodes**: Individual processing steps or tool calls - **Edges**: Transitions between nodes (can be conditional) - **State**: Persistent data passed between nodes - **Cycles**: Ability to return to previous nodes based on conditions ``` ┌─────────────────────────────────────┐ │ Agent Graph │ │ ┌──────┐ ┌──────┐ ┌──────┐ │ │ │Start │───▶│Think │───▶│ Act │ │ │ └──────┘ └──────┘ └──────┘ │ │ ▲ │ │ │ └────────────┘ │ │ (cycle/loop) │ └─────────────────────────────────────┘ ``` ## Enterprise Adoption - **Vodafone**: Autonomous agents for data engineering and operations - **Klarna**: Customer service agents with LangSmith integration - **Elastic**: AI security assistant for 20,000+ customers ## References - https://www.langchain.com/langgraph - https://docs.langchain.com/oss/python/langgraph/overview - https://github.com/langchain-ai/langgraph ## Related - [[LangChain]] - [[AI Agents]] - [[AI Agent Swarms]] - [[Large Language Models (LLMs)]] - [[Directed Acyclic Graphs (DAG)]] - [[Python]]