LangGraph (2024): Orchestrating Complex Agents
LangGraph is a framework to orchestrate complex agents built with LangChain, supporting cycles, state, and multi-agent workflows.
Beyond linear chains
LangGraph is a framework to orchestrate complex agents built with LangChain. Introduced by the LangChain team in early 2024, it addresses what linear chains cannot do: cyclic workflows, persistent state, human-in-the-loop interactions, and multi-agent orchestration.
In an AI booking platform, trip planning is not one LLM call. It requires destination discovery, hotel search, activity planning, budget validation, and itinerary assembly. Each step can fail, retry, or branch. LangGraph models that as a graph, not a chain.
Booking agent graph
from langgraph.graph import StateGraph, END
def discover_destinations(state):
state["candidates"] = hybrid_search(state["query"])
return state
def recommend_hotels(state):
state["hotels"] = hotel_agent.run(state["candidates"], state["budget"])
return state
def plan_activities(state):
state["activities"] = activity_agent.run(state["candidates"])
return state
def validate_budget(state):
state["plan"] = budget_agent.filter(state["hotels"], state["activities"], state["budget"])
return state
def generate_itinerary(state):
state["itinerary"] = itinerary_agent.assemble(state["plan"])
return state
graph = StateGraph(dict)
graph.add_node("discover", discover_destinations)
graph.add_node("hotels", recommend_hotels)
graph.add_node("activities", plan_activities)
graph.add_node("budget", validate_budget)
graph.add_node("itinerary", generate_itinerary)
graph.set_entry_point("discover")
graph.add_edge("discover", "hotels")
graph.add_edge("hotels", "activities")
graph.add_edge("activities", "budget")
graph.add_edge("budget", "itinerary")
graph.add_edge("itinerary", END)
booking_agent = graph.compile()Where LangGraph fits in the stack
RAG retrieves documents. LangChain builds the tools and chains. LangGraph orchestrates when those tools run, in what order, and with what state. For any multi-step AI product, LangGraph is the orchestration layer on top of LangChain.