Six hours at the Generative UI hackathon

Six hours on a Saturday, noon to six. Built a thing called Witness at a generative UI hackathon.

Most agent UIs are built for the agent. You inherit a chat log and a spinner, and you’re supposed to trust it. Witness flips that. Instead of one chat shape for every task, the model renders the verification surface itself, tuned to what the agent just did.

Six hours isn’t enough to ship the idea, but it’s enough to feel where it bites. The real frontier is the agent generating the UI that makes its own work auditable. That’s a different skill from writing code, and the gap is wider than I expected.