Generate a robot arm CAD model from one prompt
A text-to-cad skill let Codex produce a 7-DOF robot arm with kinematics, a GUI and STEP parts in one demo prompt, though not the gripper.
What they did
Jake Fitzgerald installed the open source text-to-cad skill package in Codex, running GPT 5.5. The agent writes build123d Python scripts, regenerates the geometry locally, and outputs STEP parts plus a URDF. In a 22-second demo, one prompt produced a 7-DOF arm with working kinematics and a custom GUI, driven almost entirely by prompting.
How it went
The arm's URDF, kinematics, GUI and STEP assembly were all generated, except the gripper. Fitzgerald says similar work would have taken weeks across half a dozen tools. Commenters questioned the joint limits and parts that wouldn't assemble.
Worth knowing
The homepage benchmark prompt was an excerpt. Real runs expand a short request into a full spec with GPT 5.5 Pro first, so vague prompts will likely do worse.
Labels
The agent writes build123d Python scripts, regenerates the geometry locally, and outputs STEP parts plus a URDF.
A text-to-cad skill let Codex produce a 7-DOF robot arm with kinematics, a GUI and STEP parts in one demo prompt, though not the gripper.
The agent writes build123d Python scripts, regenerates the geometry locally, and outputs STEP parts plus a URDF.
In a 22-second demo, one prompt produced a 7-DOF arm with working kinematics and a custom GUI, driven almost entirely by prompting.
The “Material” label failed its quality check and is not used for selection.
Details
- Agents
- Codex, Claude Code
- Source
- other
- Source date
- undated
- Accounts
- 2
- In registry since
- Oct 12, 2026