Build Your First AI Agent with LangGraph — Step-by-Step Python Tutorial (2026)

Build Your First AI Agent with LangGraph - Step-by-Step Python Tutorial AI agents are not chatbots. A chatbot answers questions. An agent decides what to do, uses tools, evaluates results, and loops until the job is done. If you have tried building agents with raw API calls and prompt chains, you know the pain: managing state across steps, handling tool failures, deciding when to loop and when to stop. It gets messy fast. LangGraph solves this. It lets you model your agent as a graph - nodes are actions, edges are decisions - and it handles state, persistence, and control flow for you.