# Parametric CAD Modeling

Builds and edits parametric CAD parts as Python models and exports STEP, STL and GLB.

- Repository: https://github.com/earthtojake/text-to-cad (24718 stars)
- Category: Design
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add earthtojake/text-to-cad --skill cad -g -a claude-code -y`
Codex: `npx skills add earthtojake/text-to-cad --skill cad -g -a codex -y`
Cursor: `npx skills add earthtojake/text-to-cad --skill cad -g -a cursor -y`
Gemini CLI: `npx skills add earthtojake/text-to-cad --skill cad -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add earthtojake/text-to-cad`

## Description

Creates and edits parametric CAD parts and assemblies as Python build123d models that cadgen's engine builds and the CAD Viewer shows live; exports STEP, STL, 3MF, GLB and xbf files on request; resolves prompt references, measures geometry, and articulates or animates assemblies. Use for 3D CAD modeling, editing a model script (any change to a part's or assembly's `.py`), organizing a CAD project, exporting or converting CAD files, Quick Edit prompts, mechanisms, and explode or showcase animations. Opens and reviews existing XBF, STEP/STP, STL, 3MF and GLB files in the CAD Viewer.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# CAD modeling and inspection

Provenance: maintained in [earthtojake/text-to-cad](https://github.com/earthtojake/text-to-cad).
Use the installed local skill files for the current interface.

A model is a Python function; running its script rebuilds it in cadgen's warm engine, and the
page the person has open updates. Files are exports, made when asked.

## Start with the task

| Task | Start with | Reference |
| --- | --- | --- |
| **Create or edit a part or assembly** | The project's model script, or a new one ([below](#write-a-model-and-run-it)). | [Models](references/model-contract.md), [build123d](references/build123d-modeling.md), [positioning](references/positioning.md) |
| **Organize a CAD project** | The project's existing layout. | [Project layout](references/project-layout.md) |
| **Export STEP, STL, 3MF, GLB or xbf** | `cadgen export <id> <file>`. | [Exports](references/exports.md) |
| **Use a vendor STEP, an xbf or a scan in a model** | `read_step`, `read_xbf` or `read_mesh` in the body. | [Inputs](references/model-contract.md#inputs) |
| **Resolve a reference from a prompt** | `cadgen inspect <id> '<ref>'`. | [References](references/inspection-and-validation.md#references) |
| **Measure or check geometry** | A check script that calls the model. | [Inspection](references/inspection-and-validation.md) |
| **See a model, a view or a pose** | `cadgen snapshot <id> out.png`. | [Snapshots](references/snapshot-review.md) |
| **Articulate a mechanism** | build123d joints in the body, then `cadgen.ap242`. | [Kinematics](references/kinematics.md) |
| **Explode, reveal or showcase a model** | `cadgen.gltf`'s `animation()` in the body. | [Animation](references/animation.md) |
| **Open an existing XBF, STEP/STP, STL, 3MF or GLB** | Show it to the user. | [Show the model](#show-the-model) |

A project built with cadgen 0.7 may need migrating: see [migrations](references/migrations.md).

The rest: https://github.com/earthtojake/text-to-cad/blob/HEAD/skills/cad/SKILL.md