Multi-Agent Workflows: State Machines and Circular Loops with LangGraph

Construct deterministic multi-agent networks featuring specialized researcher, coder, and critic nodes with cycle control.

Prerequisites

Python
Async programming
LangGraph fundamentals

Step 1: Step 1: Defining Typed State Across Agents

Agents communicate by appending structured actions to a centralized immutable state graph.

Step 2: Step 2: Connecting the Critique Loop and Halting Invariant

Define conditional edge transitions that send code back to the developer node until the test runner yields zero errors or the loop hits 3 iterations.