shipped / October 3, 2026
ldraw-nova: give an agent an idea, get a LEGO model back
anteloc has spent since last December teaching ChatGPT and Claude to write LDraw, the "assembly language" of LEGO CAD. The result is an open-source tool where an agent builds the model brick by brick.
Built by anteloc with GPT-6 Astra and Claude Opus 5.5.
see the announcement on Hacker News →instructionsdemosource
What it is
ldraw-nova is an open-source toolset that lets an AI agent design LEGO models. You describe what you want, guide it if you feel like it, and the agent writes the model in LDraw, a plain-text format where every line places one part at one position and rotation. Open the file in LDView, LeoCAD or Studio and it is a real LEGO CAD model you can spin around and edit.
The maker calls LDraw an assembly language, pun intended, and the pitch follows from that: if agents can write code, and a LEGO model is code, then agents can build LEGO.
How it was built
By the maker's own account this started last December as an experiment: could ChatGPT and Claude write LDraw the way they write Python? LDraw is almost all positions and rotations, the kind of math models are usually bad at, so the surprise was that early tests went well. Months of iteration later, using GPT-6 Astra and Opus 5.5, it has turned into a Python toolset plus instructions and docs written for agents: part search, example lookup, and the rules of the format.
It ships as a Docker web app that works with OpenAI, Claude or OpenRouter. When a build finishes you get:
- the LDraw source for the model
- a 3D viewer, a 3D player, and a VR view for Meta Quest 3
- a Blender-editable
.glbfile - the full chat history and the agent's thinking
That last one is the fun part. Each generated file records what the agent was picturing before it placed a single brick.
Why we picked it
Most agent demos end in a web app. This one ends in something you could put on a shelf. It is also a good example of what the work actually looks like: the model didn't change, the tooling around it did. Give an agent a searchable parts catalog and a format it can check, and "bad at math" stops being the blocker.
It was the maker's first post on Hacker News, and it picked up more than 130 points. The project is AGPL-3.0 and there is a gallery of generated models and a demo video if you want to see results before you install anything.
Shipped is Accept All's daily pick of things people build with AI. We are not affiliated with anteloc; the work and the credit are theirs, so go tell them it's good.