LangGraph Review 2026

LangGraph is LangChain's open-source framework for building stateful, durable, multi-agent workflows in Python and JavaScript with graph-based control flow.

LangGraph is the agent framework from the LangChain team, designed for stateful multi-agent applications where vanilla chains run out of expressiveness. Where LangChain models AI work as a linear chain, LangGraph models it as a directed graph: nodes are functions or LLM steps, edges define conditional control flow, and state is a first-class object that persists across steps with checkpointing. That makes LangGraph the right choice for agent loops with branching (router patterns), human-in-the-loop pauses (resume from checkpoint), durable long-running tasks (server-side persistence), and supervisor/worker multi-agent topologies. LangGraph is open source and free in code form; the optional LangGraph Platform adds managed deployments, observability via LangSmith, and a hosted server. Pricing follows LangChain's standard tiers: Developer at $0/seat/month (5k base traces/mo, 1 free dev deployment), Plus at $39/seat/month (10k base traces/mo, 1 free dev-sized agent deployment, unlimited seats), and Enterprise custom (advanced security, on-prem, dedicated support). Usage adds $2.50 per 1k LangSmith base traces, $0.0036/min for production deployments, $0.0007/min for dev deployments, and $1.50 per LCU (LangChain Compute Unit) for engine execution.