I Used Lyapunov Stability Theory to Monitor LLM Agents — Here's What Actually Worked and What Didn't

The Elephant in the Room: "Isn't This Just max_iterations?"

Let me address this up front.

If you're building a ReAct loop with a single LLM and 10 tool calls, you do not need a physics-inspired monitoring library. Set max_iterations=10, add a budget cap, and move on. LangGraph, CrewAI, and every modern agent framework already support this natively.

I built state-harness because I ran into a problem that max_iterations doesn't solve. And after benchmarking it across 2,367 runs, I also learned what it can't do — which I'll be equally transparent about.

The Problem That max_iterations Doesn't Solve