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Mechanism validation
Describe a gear train, linkage, or hinge in plain English. The agent generates parametric source, runs assembly + physics checks, and only ships if the mechanism actually moves.
Free resource · ToolClaude CodeCodexOpen source
AI just killed mechanical engineering.
Someone open-sourced a Claude skill that turns plain English into full mechanical designs — moving parts, physics validation, animated assemblies. URDFs for robots. 4,100 stars on GitHub in a single week.
4.1K ★GitHub stars in the first week
1 lineInstall command — same on every agent
$0Open source, runs fully local
install
# one line. works in claude code, codex, cursor.
$ npx skills add earthtojake/text-to-cad
# then, in your agent chat:
› design a 6-DOF robotic arm with mecanum wheels.
export URDF + animated STEP. validate joint limits.Text in. Real hardware out.
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STEP, STL, URDF — all of it
Export STEP for fab, STL for print, 3MF for slicers, DXF for laser, GLB for the web. Robotics? URDF, SRDF, SDF with joint limits and inertials, ready for sim.
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Animated assemblies
Parameters become sliders. Assemblies become animations. Reference any face or feature with stable @cad[…] handles so the agent can edit precisely on follow-ups.
Things people have already shipped.
Ten reference builds ship with the repo. Three that show the range — same one-prompt workflow for each.
Example 01
Planetary gear assembly
Sun + planets + ring, correct tooth count, animated rotation. One prompt — fully parametric STEP file you can drop straight into Fusion or send to print.
Example 02
Adjustable standing desk
Frame with linear actuators, joints constrained, weight + load checked. Generated as a working URDF you can simulate before cutting any metal.
Example 03
6-DOF robotic arm
Links, joints, inertials, MoveIt2 semantics. SRDF planning groups + end effector. Tested in sim, ready to bolt to your bench.
Everything you need, fully local.
AgentClaude Code / Codex
The model that writes the CAD source.
Skillscadskills.xyz
Open-source skill pack, install in one line.
Kernelbuild123d + OCP
Parametric Python CAD on OpenCascade.
ViewerCAD Explorer
Local browser preview — no backend, no login.
From zero to working STEP file.
You need an agent (Claude Code or Codex), Python 3.11+, and Node. Total time: about 5 minutes. If anything errors, paste it into the chat and let the agent fix itself — that's the whole workflow.
01
Pick your agent
The skills work with anything that speaks the agent-skills standard: Claude Code, Codex, Cursor, GitHub Copilot, Windsurf, Gemini, Cline. Pick whichever you already pay for. If you don't have one yet, Claude Code in VS Code is the easiest entry — see the content brain guide for the setup walkthrough.
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Install Python 3.11+ and Node
The CAD kernel runs on Python (build123d + OpenCascade). The CAD Explorer viewer runs on Node. Quickest path:
# macOS — homebrew
brew install [email protected] node
# windows — winget
winget install Python.Python.3.11 OpenJS.NodeJSiAlready have these? Skip ahead. The skill installer will complain if anything's missing.
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Install the skills
One line. Run this in any terminal — it adds the full text-to-cad skill pack to your agent:
$ npx skills add earthtojake/text-to-cadRestart the agent if the skills don't show up immediately. You'll get seven skills: CAD, Render, step.parts, URDF, SRDF, SDF, SendCutSend — described in detail at cadskills.xyz.
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Prompt your first part
Start a new folder, open it in your agent, and just ask. The skills handle the kernel calls — you only write English:
› design a planetary gear assembly.
sun gear 12T, three planets, ring 40T.
export STEP. animate the rotation.The agent writes parametric Python, runs the kernel, drops a STEP file in the folder, and commits the source.
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Inspect in CAD Explorer
The Render skill spins up a local viewer in your browser — no backend, no login. You see the part, scrub the animation, and copy stable @cad[…] handles for any face or feature.
Want to tweak? Paste the handle back into chat: "chamfer this edge by 0.5mm". The agent edits the source precisely — no more "the round one on the left".
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Export, fab, repeat
Ship it:
- 3D print — ask for STL or 3MF, drop into your slicer.
- Laser / waterjet — ask for DXF, run the SendCutSend skill for a preflight check.
- Robotics sim — ask for URDF + SRDF, load into MoveIt2 or Gazebo.
+Pro move: commit the Python source and artifacts together. Next iteration is a one-line diff, not a CAD-history archaeology dig.
Three ways I'd use this today.
The skills cover the whole pipeline — prompt to part to fab. Three workflows that suddenly become realistic for solo builders.
Use 01
Hardware MVPs in a day
Iterate enclosures, brackets, jigs, and mounts the way you iterate code. Commit the source, regenerate STL, print, repeat.
Use 02
Robot URDFs without the pain
Skip the days of hand-writing joint trees. Describe the robot, let the SRDF/URDF skills wire the kinematics, then plug into ROS / MoveIt2.
Use 03
Send straight to fab
The SendCutSend skill runs a manufacturing preflight on your DXF/STEP files. Bend radii, hole spacing, material gotchas — caught before upload.
Things people ask first.
Do I need to know CAD?
Not to start. You describe the part in English, the agent writes the parametric build123d source, and the viewer shows you the result. You only crack open the Python when you want surgical edits — by then you'll have read enough generated source to follow it.
Is it really free?
Yes — fully open source, MIT-licensed, runs locally on your machine. No backend, no subscription, no cloud fees. You pay only for the agent you already use (Claude Code or Codex).
Which agents work with it?
Claude Code, Cursor, Codex, GitHub Copilot, Windsurf, Gemini CLI, Cline — anything that supports agent skills. The same skill pack installs across all of them.
Can the output actually be manufactured?
That's the point. The CAD skill outputs source-controlled STEP, the SendCutSend skill checks DXF/STEP for sheet-metal gotchas, and the step.parts skill plugs in real off-the-shelf hardware (screws, bearings, motors) so the BOM matches reality.
Credit where it's due
text-to-cad is built and open-sourced by earthtojake. The skill pack and docs live at cadskills.xyz. I found it through the firehose and wrote this guide so you can ship with it the same day.
Like this? I share new drops weekly — find me on Instagram, Skool, or browse the full library.
Ship it
Stop sketching. Start prompting.
One line installs the skills. One prompt builds the part. The rest is iteration speed you've never had on hardware before.