My terminal setup these days is cmux layered on top of Ghostty, so I can run multiple workspaces side by side without losing my place. Most of my actual work happens there now, as the primary surface.
MC Dean spent real time building UIs for her designpowers agents, looked at what she’d made, and tore them down:
I’d taken something that was direct, alive in a particular way, that would show you its thinking if you let it, and I’d dressed it up. Made it presentable. Wrapped its reasoning inside a crisp ui. In doing that I’d introduced distance between the person using it and the thing they were actually talking to and trying to collaborate with. I’d made it more comfortable, predictable and less true. I killed the delight of using designpowers.
Dean on why she killed it:
The GUI was scaffolding. Brilliant, necessary, world-changing as an innovation, but nonetheless created around a fundamental limitation so invisibly useful that we forgot what it was for.
The scaffolding was for humans who couldn’t speak the machine’s language. When the machine starts speaking ours—even partially, even just inside certain conversations—the scaffolding becomes friction for anyone trying to learn how the underlying system actually thinks.
Dean then connects this back to design craft, instead of letting it become a “designers should learn the terminal” finger-wag:
Designers are really good at this important way of thinking already. Every time you decided how an error message should make a person feel. Every time you chose what to surface and what to hide. Every time you designed for the person who didn’t fit the assumed user, you were encoding values into a system. That work doesn’t go away when the interface does. It moves upstream, into the reasoning layer itself, and it has no canvas. That’s design literacy for the world that’s coming.
Dean’s argument pairs with the other end of the same expansion: designers gaining authorship downstream in the code. The easing curve and the hover state at one end; what the agent gets to surface and who counts as the assumed user at the other. The reasoning layer is the upstream end without a canvas to hide behind.
Nick Babich asks if the old surface still earns its place. Dean is pointing at where the new surface already is.
Dean closes with:
We are early enough that the agents are still legible. You can still watch one think. You can still feel the shape of how it reasons before it’s been wrapped in chrome and shipped with a logo.
That window is why I bother with cmux at all. Ghostty by itself is already a genuine pleasure to use; cmux lets me keep a Claude Code session running per project without losing context when I switch. Just enough plumbing to make watching agents think a habit rather than a stunt. Dean’s right that the legibility won’t last. Worth being here while it does.

The Terminal Belongs to Designers Too
MC Dean built beautiful UIs for her AI agents, then looked at what she’d made and took them all down. The GUI was scaffolding. The terminal lets you watch the agent think. Design craft moves upstream into the reasoning layer, where it has no canvas.



















