Simon Willison’s Weblog

Leaked system prompts from Vercel v0. v0 is Vercel's entry in the increasingly crowded LLM-assisted development market - chat with a bot and have that bot build a full application for you.

They've been iterating on it since launching in October last year, making it one of the most mature products in this space.

Somebody leaked the system prompts recently. Vercel CTO Malte Ubl said this:

When @v0 first came out we were paranoid about protecting the prompt with all kinds of pre and post processing complexity.

We completely pivoted to let it rip. A prompt without the evals, models, and especially UX is like getting a broken ASML machine without a manual