pingdotgg/uploadthing ? reverse-engineered prompt

Build me a simple file upload toolkit for modern web apps, with a clean docs site and a few working examples so I can see how to use it right away.

I want it to make uploading files feel easy in React, Solid, and Next.js, with a reusable upload button or drop zone, server side setup, and clear docs for getting started. Please include a basic working demo for a Next.js app router example, a Next.js pages example, and a SolidStart example, plus a polished landing style docs page that explains what it does in plain language.

The main goal is to let a developer plug this into an app and start uploading files without a lot of setup. Keep the experience simple, modern, and friendly. If you need to check current library docs or best practices online, go ahead and do that.