BrickBuilder

A LEGO® building agent. Tell Pip what you want to build, or give it a reference image. BrickBuilder uses an LLM to design the model, checks the build, and gives you a 3D preview, building instructions, a parts list, and downloadable LDraw files. You can ask for changes and keep building from the result.

Use in ChatGPT

Add the BrickBuilder plugin to ChatGPT to build with BrickBuilder from your chats.

Choose your builder

Mode	How it builds
Basic bricks	An OpenAI or Claude model designs shapes on a stud grid. BrickBuilder checks the design, shows the model a preview for revisions, and converts the result into bricks.
All parts	The Nova agent works with a wider parts catalog. It can search parts, write building scripts, render and check its work, and continue the same build when you ask for an edit.

At brickbuilder.ai, describe a build, optionally upload an image, choose Basic bricks or All parts, and press Create. For example: “Build a small red lighthouse with a blue door, about 20 studs tall.”

Run locally

Install Node.js 18+, Python 3.10+, and Git. For All parts, also install and start Docker Desktop; Nova runs in Docker.

cp backend/.env-example backend/.env
cp frontend/.env-example frontend/.env

Set OPENAI_API_KEY or ANTHROPIC_API_KEY in backend/.env for Basic bricks. For All parts, you can use a project API key or connect your OpenAI or Claude account through the local provider sign-in.

npm install
npm start

Open the local URL printed by the frontend server, choose a mode, and start building. If you only want Basic bricks, run both npm commands with NOVA_SKIP_SETUP=true to skip Docker and Nova.

See the LLM builder details and Nova setup guide for more options.

License

MIT. LEGO® is a trademark of the LEGO Group, which does not sponsor, authorize, or endorse this project.