Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add ForgeCAD/forgecad-public-kit --skill forgecad-verify-mujocogit clone --depth 1 https://github.com/ForgeCAD/forgecad-public-kitWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/forgecad/forgecad-public-kit/forgecad-verify-mujoco)<a href="https://agentmods.dev/skills/forgecad/forgecad-public-kit/forgecad-verify-mujoco"><img src="https://agentmods.dev/badge/skills/forgecad/forgecad-public-kit/forgecad-verify-mujoco/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/forgecad/forgecad-public-kit/forgecad-verify-mujoco"><img src="https://agentmods.dev/badge/skills/forgecad/forgecad-public-kit/forgecad-verify-mujoco.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00038 | $0.01467 |
| Opus 5 | $0.00019 | $0.00733 |
| Sonnet 5 | $0.00008 | $0.00293 |
| Haiku 4.5 | $0.00004 | $0.00147 |
Grade C, and why
forgecad-verify-mujoco scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Recursive force deletehighDestructive command
rm -rf with a variable or a broad path is one typo away from removing the wrong tree.
rm -rf /tmp/forgecad-mjcf && mkdir -p /tmp/forgecad-mjcf How it starts
The opening of the file, as written. The whole thing — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Verify MuJoCo
Use this when forgecad export mjcf ... is part of the deliverable. A model is not sim-ready just because forgecad check simready passes or the MJCF file loads: it must be loaded in MuJoCo, stepped under gravity, driven with the intended controls, contact pairs inspected, and rendered from useful views.
Routing: geometry-only visual inspection -> forgecad-inspect-model; model authoring/API questions -> forgecad; building a new model -> forgecad-build-model.
Definition Of Done
- Export from the exact source file.
rm -rf /tmp/forgecad-mjcf && mkdir -p /tmp/forgecad-mjcf forgecad export mjcf path/to/model.forge.js --output /tmp/forgecad-mjcf - Load the generated scene in MuJoCo. Use
scene.xml, not only the model XML, so the floor/camera/package context is included. - Check the root behavior. If the model has a free root, it needs real support/contact geometry or an explicit fixed-root export path. Do not hide a floor failure by turning the whole shell into a giant bounding box that blocks moving internals.
- Check initial poses numerically. For mechanisms, compute the expected body/link axes from the design source and compare them to MuJoCo
xmat/xpos. Jointref/default and connector frames can disagree with visual intuition. - Keep meaningful collisions. Do not mark moving functional parts
Sim.collider.none(...)just to make motion pass. If full visual mesh contact is unstable, use a physically defensible simplified collider or proxy and state what physical surface it represents. - Run the intended control with numeric acceptance criteria. Define the expected signed post-settle joint travel before running the test: e.g. "this drive should rotate the drum -0.04 to -0.06 cycles, then stop near zero velocity" or "this wheel should move at least +1 cycle and keep spinning". Use cycles for revolute/indexing mechanisms when that is easier to reason about, and radians for direct MuJoCo qpos checks. A controller that only jitters, moves the wrong direction, overshoots through a stop, or eventually jams after skipping the intended state is a failure even when the process exits 0.
- Inspect contact pairs. Contact names should match the physical story: floor/support, card/card, wheel/ground, stop/follower, etc. Contacts against a filled-in AABB, hidden fixture, or unrelated side plate usually indicate bad collider selection.
- Render evidence. Save initial, settled, and driven frames from views that actually show the moving parts. If the model orientation is not obvious, generate a labeled camera preview grid first, inspect it, then rerun with the azimuth/elevation that shows the functional face. Do not report GIFs/frames before visually confirming they are not from the back, underside, or an occluded side.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 67 lines · 38 tokens per session scan C 8929cfb52012
forgecad-verify-mujoco is a skill published in the GitHub repository ForgeCAD/forgecad-public-kit (931 stars, last pushed 2mo ago), licensed MIT. It adds 38 tokens to every session and 1,467 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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