Prototo runs on a Mac with Apple silicon. Everything else, the app sets up with you.

Step 1: Download Prototo Desktop

Download Prototo for Mac , open it, and drag it to Applications.

Step 2: Let it check your Mac

The first time it opens, Prototo checks for everything it needs and walks you through anything missing, one item at a time:

• Xcode. Apple’s developer tool. Prototo uses its iOS Simulator, the iPhone preview that runs on your Mac. You never open Xcode itself. It’s free from the Mac App Store .
• The iOS Simulator. Installed alongside Xcode.
• Node.js. A small runtime your prototypes run on. Free from nodejs.org .
• A coding agent. It turns plain language into working screens. Prototo works with Claude Code (recommended, from Anthropic) and OpenAI Codex. Pick the one you already pay for: Prototo runs on the AI subscription you already have and never charges for AI use.

Each item shows a tick once it’s ready. Anything missing comes with the exact step to fix it, then Prototo checks again.

Using Claude Code? See Configure Claude Code for optional extras.

Step 3: Create your first project

Click New project, give it a name, and Prototo sets it up and opens it: your agent on the left, a live iPhone on the right with the starter screen. That’s it. You’re ready for your first prototype.