I think this is a really good explainer.
But I have a slightly different explanation that’s pretty elegant to remember.
1. Both models and harnesses are made to help you get what you want from AI
2. Models are getting much better, but they can only do so much because they don’t know everything about you and how you like things to be done.
3. Harnesses are like model assistants. They help the model get the information that it needs to help you in a way that matches your preferences.
4. In general, the better the models get, the less you will need the harness because they are ultimately pursuing the same goal of getting you exactly what you want.
5. The best harnesses today are focused not on micromanaging the steps to use to accomplish something (we should leave that to the model), but instead on describing exactly how you like things to be done. The more the harness knows about you and your preferences, the better it can provide the model what it needs to give you the best result.
Good Harness Engineering is good because no matter how smart an AI becomes it will still be better at getting you great results if it understands who you are and what you like. Good and Bad Harness Engineering (April 2026)
6. In other words, the model is the “how” and the harness’s job is to provide the highest quality “what”.
The WHAT half appreciates. Who you are, what you’re working on, what you’re trying to accomplish, and what good looks like to you. A smarter model does more with that context, not less. The Answer to the Harness Question (July 2026)
