LangGraph Agent Build | StateGraph + ToolNode + Groq LLM | 03/04 |

🧠 (03/04) This is the CORE video of the series. We build the actual AI Agent using LangGraph's StateGraph — connecting the LLM to tools with conditional routing. By the end of this video, you'll understand exactly how an AI agent "thinks" — how it decides which tool to call, executes it, reads the result, and loops until it has an answer. 📌 What you'll learn: • Setting up ChatGroq with LLaMA 3.1 8B Instant • SQLDatabaseToolkit — auto-generated SQL tools • Binding tools to the LLM (llm.bind_tools) • Defining State with TypedDict and add_messages • Building the Assistant Node (LLM reasoning) • Building the Tools Node (ToolNode execution) • Conditional edges — how the agent decides: tool or answer? • Enforcing sequential tool calls (one at a time) • Compiling the graph (builder.compile()) • Running the agent & reading state logs • Full walkthrough: "What is revenue for SKU-6?" 📂 File covered: • agent.py — The complete agent implementation 🔑 Key Concepts: • StateGraph — a directed graph where state flows between nodes • ToolNode — prebuilt node that executes tool calls • tools_condition — routes to tools or END based on LLM output • State accumulation — full message history enables multi-step reasoning This is Part 3 of a 4-part series where we build a complete AI Agent with LangGraph + Groq + Streamlit. 🔗 Full Series: ▶️ Part 1: Theory (LangChain & LangGraph) ▶️ Part 2: Database, Tools & Prompt Setup ▶️ Part 3: Building the Agent (agent.py deep dive) — YOU ARE HERE ▶️ Part 4: Streamlit UI & Deploy on Replit 💻 Source Code: https://github.com/Suarj6133/Langchai... ⭐ Star the repo if this helps! ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⏱️ TIMESTAMPS: 0:00 — Introduction — what makes this the "brain" 1:30 — Importing dependencies & architecture 6:31 — ChatGroq LLM setup (temperature=0 explained) 7:50 — SQLDatabaseToolkit — what tools it gives us 8:00 — Combining SQL tools + custom tools & giving LLM superpowers 9:30 — Defining State (TypedDict + add_messages) 10:20 — Assistant Node — the reasoning function 11:50 - State Graph sequential diagram 14:11 — Sequential Diagram - 15:30 - Adding nodes and edges 17:15 — add_edge & conditional_edge 18:15- Live demo — "What is revenue for SKU-6?" ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔍 HASHTAGS: #LangGraph #AIAgent #Python #StateGraph #Groq #LLaMA #LangChain #Tutorial #BuildAIAgent #ToolNode #MachineLearning #AgentPy #LLMAgent ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━