Everyone has an idea every now and again for a little online tool or game that ought to exist but doesn’t. “There should be an app for that,” we say wistfully, then we move on with our day, since most of us can’t code and are never going to pay a professional to turn our passing idea into reality.

But thanks to large language models (LLMs), there are now platforms such as Cursor and Replit that make it possible to “code” by simply typing instructions in natural language. Welcome to “vibe coding”, a term coined this year by Andrej Karpathy, a former Tesla and OpenAI engineer. Karpathy said it was fun for “throwaway weekend projects” to just “fully give in to the vibes” and “forget that the code even exists”.

Intrigued, I gave it a go. My brother, a professional computer programmer, sat next to me in case I got stuck. I wanted to make a very simple app that would allow me to pretend with my five-year-old daughter that my phone was an X-ray machine.