Snap a photo of your loose LEGO bricks and get build ideas made from exactly those pieces, with 3D step-by-step instructions you can turn, zoom and print. Or describe any model and get one. Powered by Claude; every stud checked.
Mister Blocks started as a project for my son. We have the classic giant box of mixed LEGO, with sets long broken up and instructions long gone, and "what can I build?" never had a good answer. Now he takes a photo of the pile, and a few minutes later there are a few builds made from those exact bricks, with 3D step-by-step instructions. The first working version came out of the very first prompt to Claude; the next days went into making the bricks display and fit together correctly.
Our stack
Claude Opus 5.5 (reads the photo, designs the builds), Vercel serverless functions in plain Node (no framework), Cloudflare Workers and R2 for images and PDFs, MongoDB, a three.js brick viewer, and a stud-by-stud checker that sends every problem back to Claude until the model holds together.