m3e-canvas bets the bottleneck in AI-assisted UI work is the spec, not the code.

Created September 2 and at 3,005 stars three days later, it's an MIT Next.js 16 / React 19 app where you sketch Material 3 Expressive screens in the browser, link them, tap through the prototype, then copy out a prompt for your coding tool. As someone with 20 years of design background, I think that's the right bet. Most of what I fix in agent output isn't broken code, it's the wrong thing built correctly (GitHub).