LangGraph

LangGraph is an open-source framework developed by LangChain Inc. for building stateful, multi-step agent workflows as directed graphs. While LangChain provides the foundational primitives for connecting LLMs to tools and data, LangGraph adds the control flow layer—enabling developers to define complex agent behaviors with cycles, branching, persistence, and human-in-the-loop checkpoints.

LangGraph's graph-based architecture allows developers to model agent systems as state machines where each node represents a step (LLM call, tool invocation, decision point) and edges define the flow between steps. This approach is particularly powerful for multi-agent systems where different agents need to collaborate, hand off tasks, and maintain shared state across long-running workflows.

In the Seven Layers of the Agentic Economy, LangGraph operates at Layer 2 (Creation & Orchestration) in the Orchestration / Agent Runtime subsection—providing the execution framework that developers use to build and run production-grade agent systems.