Agent Patterns Lab
Class 8: Reflection & Planning
Overview
Labs
Lab 1
Reflection: One Pass
Lab 2
Reflection: The Loop
Lab 3
Planning: The Planner
Lab 4
Planning: The Executor
Lab 5
ReAct vs Reflection vs Planning
Lab 6
LangGraph Anatomy
Tech Leaders Hub — Class 8
Lab 6

LangGraph Anatomy

Step through the building blocks of a LangGraph — nodes, edges, conditional edges, shared state, START and END.

Graph Structure

STARTLLM Nodereads state → calls LLM → updates stateconditionaledgeneeds toolhas answerTool Nodeexecutes tool callsENDloop backShared Statemessages: [...]tool_calls: [...]next: "llm" | "tools" | "end"
Step 1 of 8

A LangGraph is a State Machine

Every LangGraph has the same building blocks: nodes, edges, and shared state. Click through to learn each one.

Node
A function that reads state, does work, writes state
Edge
A fixed path from one node to the next
Conditional Edge
A decision point — routes based on current state
Shared State
The data object that flows through every node
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Next Class: Build a LangGraph Agent From Scratch

You've seen the anatomy. Next class, you'll write the nodes, edges, and state yourself — in Python.