Branching Logic

A linear chain is dumb. It does the same thing for every input. A graph is smart. It adapts.

Visualizing Branches

graph LR
    Start --> Condition{User Intent?}
    Condition -- "Refund" --> RefundNode
    Condition -- "Tech Support" --> SupportNode
    Condition -- "General" --> ChatNode

The Condition Function

In LangGraph, logic lives in a plain Python function.

def choose_route(state):
    user_input = state["messages"][-1]
    # Simple keyword check
    if "refund" in user_input:
        return "billing"
    else:
        return "support"

Adding the Conditional Edge

You attach this function to a node. graph.add_conditional_edges("start_node", choose_route)