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/Langchain_Langgraph_tutorial.git
⭐ 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

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Видео LangGraph Agent Build | StateGraph + ToolNode + Groq LLM | 03/04 | канала honest pm iimbangalore