A Cursor canvas is a .tsx that imports only from cursor/canvas. That module isn't an installable package, it's provided by the Cursor IDE at compile time, so a canvas can't build or render anywhere outside the IDE. This project is an open, Mantine-backed shim of cursor/canvas. A build-time Vite alias swaps the module for the shim, so the same .tsx renders in the Cursor IDE and on the web.