Building a multi-agent system with LangGraph
A single agent with a big prompt and a pile of tools works fine until the task branches: one part needs research, another needs code execution, another needs a human sign-off before it does anything destructive. At that point you're better off with several narrow agents coordinated by explicit control flow than one agent trying to hold all of it in its head. LangGraph is built for exactly that — it models an agent system as a graph of nodes and edges over a shared state, instead of a single hidden loop.