this harness engineering paper is f*cking insane
it's the exact 3-agent setup anthropic used to turn a one-line idea into a working app instead of a broken demo.
3 agents, 3 files, one loop that doesn't stop until the app actually works, all on one page.
set it up tonight and your agent ships features that work on the first click, instead of "done" apps that break the moment you touch them.
the crazy part is everyone lets the same agent build its work and grade it, while the fix is a second agent whose only job is to say no.
full breakdown in the harness guide below.
Harness, loop and graph could be the missing layers between AI models and agents that actually work.
Same model, same prompt, completely different results.
In this article, I show you how to build all three layers.