Anatomy of an Agent Harness
The live demo repo for this series is 67ailab/harness-engineering, and this post stays anchored to the code that exists there today. I did not add a new repo capability for this article. The point of this installment is to dissect the current harness as it actually stands: what lives in src/harness_engineering/, how the pieces fit together, and which parts are carrying the reliability burden. That matters because “agent” is now a dangerously overloaded word. Many teams still mean either a model that can call functions or a prompt loop with some memory and tool wrappers. Those are ingredients, not a runtime anatomy. ...