Amp co-creator Thorsten Ball: how I prompt coding agents
Thorsten Ball, co-creator of the coding agent Amp, explains his prompting method at Laracon US 2026. Amp is 99% written by AI, and his prompts are text-heavy, with no MCP servers or frameworks. The core mental model: when you write a prompt, ask how the model is supposed to know what you mean, and where the information should come from. He walks through a large prompt used to build Amp's daemon mode.
That's what the model experiences. So, when you write a prompt, you have to think about the reader. The goal of all writing is to be understood.
- r5Khe
Loved this. It's funny how basic all of this can be. We have all these skills and and tricks and incantations whatever else, when it probably all just comes down to giving the agent the right info to set them up for success (just like you'd do with anyone you're delegating anything to).
- CSSer
The thing about this is that in a different codebase, even just that search for the trumpet guy could either burn a ton of tokens and come back with nothing or find it but light the ocean on fire in the process. This is because trumpet guy would be named "asset-ds1f23nbiq35421fsda.jpg", and it would be located in an images folder with thousands of other similar assets. So the agent starts by grepping for reasonable names, discovers nothing but finds an image directory, and then searches inside. In the worst case, I guess it starts analyzing each image. Or maybe it checks the article like he mentions, but the codebase uses a component library and the filename thing is still true, so it analyzes every image in the page. This is a bit of hyperbole, of course. Please allow it for the sake of comedic example.
Many of his other prompt examples also illustrate this. The author is massively leveraging the architecture of the organization through familiarity. It could well be the case that even an LLM was used to set that up, but I doubt it happened in one prompt or without critical thought. To be fair, I guess he's sort of trying to point that out, but by saying "Look how lazy I am while it still works" or something like that in order to look cool, I think all he's conveying is "Look how easy this is", when it's potentially not and could increasingly cost him/his company wildly varying amounts of money based on how he goes about it. When tokens were virtually free, no one cared. This […]