LangGraph

LangGraph is a framework for building stateful AI agents, sitting on top of LangChain. Where LangChain is best for linear chains, LangGraph models the agent as an explicit graph of nodes (steps) and edges (transitions) with shared state, which makes loops, branching, and human-in-the-loop checkpoints first-class. It's the de-facto way to build non-trivial agents in the LangChain ecosystem.