Langgraph

This is LangChain's recommended way to build production agents using explicit graph structures instead of abstract loops. You define state with reducers, create nodes for agent logic and tools, then wire them with conditional edges to control flow. The ReAct pattern with tool calling is straightforward, and the checkpointer system lets you persist and resume conversations. Used at LinkedIn and Uber, which tells you it handles real production load. The graph approach makes debugging way easier than black box agents, though you'll spend time learning the state management patterns. If you're building anything beyond a simple chatbot, the structured approach pays off quickly.