sdf skill (earthtojake) for Claude Code: write and validate SDFormat robot models

Makes Claude write and validate SDFormat (.sdf) robot models and simulator worlds, then show you the result.

Installs: 11.3K; on skills.sh
Stars: 24.7K; on GitHub
Files: 11; besides SKILL.md
Updated: Nov 2026; last repo commit

sdf makes Claude author SDFormat XML directly, validate every file it writes with cad sdf validate, and show the result in a viewer before it reports back. Its description says to use it for .sdf files, models, worlds, joints, poses, frames, sensors, lights, physics and Gazebo, and not for signed-distance-field geometry.

The skill is part of text-to-cad and runs a cad command that the text-to-cad installer sets up. Claude first writes a design ledger as a comment block, writes explicit relative_to frames, then validates. It reports checks it ran and checks it skipped.

Good for

Robotics developers writing models and worlds for Gazebo or other simulators
Engineers converting a URDF into an SDF model
Anyone reviewing an .sdf file for frame, joint and inertia mistakes

Install sdf

Claude Code

Copy this prompt.

Install the sdf skill in Claude Code. Run this command:

claude plugin marketplace add earthtojake/text-to-cad#latest
claude plugin install text-to-cad@earthtojake

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires uv.

The skill runs a cad command. The plugin and the installer both set it up; a skills-only install needs the installer too.

From the project README. Source.

What's in the skill

When it loads

SDFormat/SDF model and world authoring, validation, and simulator handoff. Use for `.sdf` files, SDFormat XML, models, worlds, links, joints, poses, frames, inertials, visual/collision geometry, mesh URIs, sensors, lights, physics, plugins, includes, Gazebo, static SDF review, or simulator-specific metadata. Do not use for signed-distance-field geometry. Open and visually review existing SDF files in CAD Viewer.

Sections in SKILL.md

Setup
Core rules
Scope
Show the model
Workflow
Commands
Required report shape
Snapshot Tool
References

Key facts

Author: earthtojake (text-to-cad)
Repository: earthtojake/text-to-cad
License: MIT
Part of: text-to-cad (12 skills in the repo)
Needs: The cad command from text-to-cad, installed by its script
Installs on skills.sh: 11,323 (Nov 2, 2026)
GitHub stars (repo): 24,721 (Nov 2, 2026)
Last repo commit: Nov 1, 2026
Files: 11 files including SKILL.md (8 reference files, LICENSE, agents/openai.yaml)

What it includes

Runs the cad command, and runs the text-to-cad install script if cad is missing.
Install is curl -fsSL https://texttocad.dev/install.sh | sh, or irm ... | iex on Windows.
Runs code · Setup
Author XML directly, SI units, version 1.12, explicit frames, validate before reporting.
Core rules (12)
A comment block at the top of the .sdf that records frames, units and assumptions.
Write · Design ledger
Checks structure, frames, joints, geometry, meshes, inertials, sensors and plugins.
Options are --strict, --json and --gz-check auto, required or never. It runs gz sdf --check when gz is on PATH.
Runs code · cad sdf validate
Draws the model to a PNG still, with optional joint poses and display modes.
Writes the PNG path you give it, for example review.png.
Runs code · cad snapshot
Opens the model in the CAD viewer or returns a link with cad viewer --json.
Runs code · Show the model
Locate, ledger, frames, author, validate, smoke-test, show, report.
Workflow (8 steps)
Lists what was validated, checks run or skipped, assumptions and risks.
Required report shape
Workflow, examples, guardrails, ledger, frame semantics, validation, smoke tests, interop.
References (8)

From the official docs

Permissions

Medium risk

The skill holds instructions, but its setup runs an install script that changes your agent apps and starts a local server. Read the script or run it with --dry-run first.

What it can do

Read your data
Create and change things
Delete things
Read-only mode

Watch out for

Setup runs an install script from the internet
The skill's Setup section tells Claude to run curl -fsSL https://texttocad.dev/install.sh | sh if cad is missing. Per the install docs it installs uv, downloads the CAD runtime and sets up every agent app it finds. Run it with --dry-run first. github.com
It edits your agent apps' plugin setup
The installer adds the plugin or skills to each agent app it finds and keeps a receipt. The --uninstall option undoes what the receipt records. github.com
The plugin starts a local server
The plugin brings CAD's viewer, a local server (cad-mcp) that runs through uvx. cad viewer opens models in your browser. github.com
Usage stats and crash reports are on by default
The README says they carry a random ID and never include your files, paths or prompts. Add --no-telemetry to the installer to turn them off. github.com
Validation can call gz on your machine
cad sdf validate runs gz sdf --check whenever gz is on PATH. Use --gz-check never to skip it. gz does not run on documents that name remote includes unless you pass --gz-remote. github.com

Technical details

Talks to	texttocad.dev (install script). The CAD release and Python 3.14, downloaded by uv on first run. Usage stats and crash reports (host not named; see the privacy policy)

Questions

How do I install the sdf skill?

Use the install box above. The skill needs the cad command, which comes from the text-to-cad plugin or installer. A skills-only install also needs the installer. Python 3.14 is managed by uv.

Is this about signed distance fields?

No. SKILL.md says it is for SDFormat, the format for simulator models and worlds, not signed-distance-field geometry.

Do I need Gazebo installed?

Not for the built-in validator. SKILL.md says gz sdf --check runs only when gz is on PATH, and skips with a note otherwise. Use --gz-check required to make it mandatory.

sdf vs urdf?

They are separate skills in text-to-cad. SKILL.md says that if the robot already has a URDF, derive the SDF from it. The urdf skill's description covers the robot's structure (links, joints, limits, inertials, mesh references) and excludes MoveIt2 SRDF semantics and the mesh source files.

Does it send my data anywhere?

The README says text-to-cad sends usage stats and crash reports by default, tagged with a random ID and never including your files, paths or prompts. The installer has a --no-telemetry option.

Is it safe to install?

The skill folder has Markdown, a LICENSE and a small agents/openai.yaml, and no script files. The setup runs an install script and starts a local server, which the permissions section describes.

Does it work in the Claude app?

The README names Claude Code, Codex, Cursor, Gemini and Grok. The install docs add Claude Desktop's Chat tab through its config. A zip upload to claude.ai is not documented, and the skill needs a local cad command.

Information

updated Nov 2, 2026

Repository: earthtojake/text-to-cad
Folder: skills/sdf

earthtojake/text-to-cad skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 7

text-to-cad README · github.com
Installing text-to-cad by hand · github.com
SKILL.md · github.com
skills.sh listing · skills.sh
Repository · github.com
urdf SKILL.md · github.com
sdf interoperability.md · github.com