Made an open-source Lego AI generator

A closer look at Made an open-source Lego AI generator

What this repository does

This GitHub project provides agent tooling to build generative LEGO models using ordinary JSON plans and LDraw parts. The tools find parts and reference constructions, generate editable MPD files, run geometry checks, render previews, and compare parts lists.

There are Python generators for larger procedural designs and a CLI workflow for review and building that produces previews, validation reports and BOM comparisons tied to a model revision.

How you actually use it

You give an agent a model idea and an instructions.md, write a JSON plan (or use Python for calculations/loops), then run review to produce previews and checks. The build command infers output/my-model.mpd and writes the MPD only after source/geometry checks pass.

The repo includes reference data and connector metadata. review --no-render skips rendering but runs intermediate Python checks, and ./ldraw-agent doctor reports local dependencies. Existing commands like build --output and individual check/render commands remain supported.

Who will find it useful

Developers and hobbyists who work with LDraw parts, editable MPD models and programmatic/agent-driven LEGO generation will benefit most. Users who want editable source, visual-review artifacts and machine-checked evidence for a generated model will find the workflow relevant.

People planning to run the optional semantic reference search should be prepared to set a TypeSafe API key, while those preferring offline catalogs can use the full-text search engine alternative.

Running the web app and extras

A sibling repository provides Docker and the web app. Clone matching release tags, install Git and Docker, then start the app; it serves interactive 3D/VR views and conversation history at http://localhost:8765 or https://localhost:8443 for VR (self-signed certificate).

The CLI can prepare semantic GLB exports for Blender via ./prepare-glb.sh using an mpd2glb.sh converter, with the editable MPD remaining the authoritative model.

Questions people ask about Made an open-source Lego AI generator

What do I need installed to run the tools locally?

You need Python 3.12+, an installed LDraw parts library, Poppler (pdftotext) and LeoCAD on PATH; the repository includes the reference data and connector metadata.

Does the web app require login?

No, the app has no login and should be run on a trusted network.

Is the semantic reference search mandatory?

No, semantic search using jev-rerank and a TypeSafe API key is optional and offline/full-text search engines remain available.

Made an open-source Lego AI generator was shared on NexURLs by Nexis on November 1, 2026, in Design & Art.