Once Prototo is installed and your Simulator is open, open a second Terminal window and navigate to your project:

cd myapp
claude

You’re now in Claude Code inside your Proto project. Claude Code has already read your DESIGN.md and CLAUDE.md — it knows your design system, your component library, and the rules for generating screens. You don’t repeat yourself.

Describe your first screen

Type this into Claude Code:

add a settings screen with notification and dark mode toggles

Watch the Simulator. In about 10 seconds your screen appears.

Real native layout. Real scroll physics. Your design system applied automatically — colour, typography, spacing, shape, all pulled from DESIGN.md.

Iterate with prompts

Keep describing. Claude Code keeps generating.

make the quick action buttons pill-shaped with an icon
above the label, arranged in a row with equal spacing

add a bottom nav with Home, Cards, Activity and Profile tabs

add a profile screen with a large avatar, the user's
name and bio, and a grid of recent posts

Each prompt updates the Simulator in seconds. You never touch a file.

What just happened

The flow is the same every time:

1. You type a prompt in Claude Code
2. Claude Code reads DESIGN.md and CLAUDE.md for context
3. Claude Code writes a new screen file to /screens/
4. The Simulator hot-reloads — the screen appears

Total time: ~10 seconds.