This feels like Cursor + v0. From the GitHub project README:

Claude, v0, etc are incredible- but you can't install packages, run backends or edit code. That’s where Bolt.new stands out:

1. Full-Stack in the Browser: Bolt.new integrates cutting-edge AI models with an in-browser development environment powered by StackBlitz’s WebContainers

2. AI with Environment Control: Unlike traditional dev environments where the AI can only assist in code generation, Bolt.new gives AI models complete control over the entire environment including the filesystem, node server, package manager, terminal, and browser console. This empowers AI agents to handle the entire app lifecycle—from creation to deployment.

Also open source on GitHub: https://github.com/stackblitz/bolt.new

System prompt: https://github.com/stackblitz/bolt.new/blob/main/app/lib/.se...

"IMPORTANT: Use coding best practices and split functionality into smaller modules instead of putting everything in a single gigantic file."

"ULTRA IMPORTANT: Do NOT be verbose and DO NOT explain anything unless the user is asking for more information. That is VERY important."

it's so weird to me that this is how we're programming user-facing systems now