The brainstem has a small toggle in Settings: **Hand display: Pills Cards**. Both modes show the same loaded agents above the chat input. Both modes do the same thing on click — send a starter prompt to the chat. The difference is purely visual.

Pills are blue text buttons that say things like “What are the top 5 stories on Hacker News right now?” They look like every chat-app’s quick-reply chip you’ve ever seen. They’re boring. They take half a second to read. Click one, send it, get an answer.

Cards are miniature holographic playing cards tucked behind the chat input bar. The tops peek up; hover lifts them to show a tiny title and the agent’s hero glyph in a cyan glow frame. They look great. They’re memorable. They scream this is a different kind of product.

The default is pills.

That’s not the obvious answer, given how much work went into the cards. The cards are what makes this brainstem feel like its own thing — the binder, the deck metaphor, the holographic projection of an agent in your hand. The cards are the brand.

But the question we kept asking was: who is the chat for?

Answer: people who want to ask their AI a question. They open the page, they have a thing to ask, they ask it. The pills tell them what they can do with one glance, in plain text, from a known design pattern. They click and move on. The first thirty seconds of the user’s experience is “this works.”

Cards work too. They’re delightful. But they require the user to learn a metaphor before they can use them. What’s a hand? Why are these cards behind the input? What happens when I hover? What’s a holo card? For a user who came here to ask a question, all of that is friction.

So the default is the boring thing that gets out of the way. The interesting thing is one click in Settings.

The same logic applies to a lot of the brainstem:

  • Live execution mode is the default; stub mode is the toggle. Most users want their agents to actually run.
  • The model selector defaults to whatever the user picked last. The full Copilot catalog is one click away.
  • Pills are 12px text. Cards are 130px tall.
  • The “Sign in with GitHub” button is the only colored button in the header. Everything else is grey.

Defaulting to boring isn’t a comment on what’s better. It’s a comment on what gets out of the way. The interesting choices we made are visible to anyone who looks for them. The defaults are calibrated for someone who doesn’t.

Card mode exists. We’re proud of it. It’s not the front door because the front door has to work for someone who’s never heard of us.

(For business users specifically, this matters extra. A clean blue pill row is sellable in a slide deck without explanation. A holo card fan invites the question “is this a game?”)