Agent skill

Matterjs

A skill your agent uses when implementing 2D physics interactions with Matter.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and…

Apache-2.0Auto-check passedFrontend & Design

Install Matterjs

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .claude/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .claude/skills/matterjs && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .claude/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .agents/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .agents/skills/matterjs && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .agents/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .cursor/skills/matterjs && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .cursor/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/nirholas/three.ws.git --path third_party/designcode-agent-skills/agent-skills/web-design/matterjs

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .gemini/skills/matterjs && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .gemini/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .github/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .github/skills/matterjs && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .github/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add nirholas/three.ws --skill matterjs -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install nirholas/three.ws matterjs --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nirholas/three.ws.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/third_party/designcode-agent-skills/agent-skills/web-design/matterjs .opencode/skills/matterjs && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "matterjs" agent skill from https://github.com/nirholas/three.ws/tree/main/third_party/designcode-agent-skills/agent-skills/web-design/matterjs into .opencode/skills/matterjs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "matterjs", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: matterjs
GitHub stars: 226
Used in: 1 other repo
Token cost: ~557 tokens
SKILL.md length: 163 words
Files: 4
Skills in repo: 165
Repo updated: Oct 7, 2026
First seen: Oct 7, 2026
Licence: Apache-2.0

At a glance

A skill your agent uses when implementing 2D physics interactions with Matter.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and…

Works in 4 steps: Confirm environment (plain HTML, React,… → Provide a minimal… → Add interactions (mouse constraint) or… → …
Implementing 2D physics interactions with Matter.js
SKILL.md covers Workflow, Minimal setup, Common patterns and Mouse interaction (optional), plus 2 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Matterjs is an agent skill from nirholas/three.ws. Use when implementing 2D physics interactions with Matter.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and scroll/interaction-friendly canvas scenes.

Its SKILL.md is about 560 tokens, which your agent loads only when the skill is triggered. The skill folder holds 4 other files (for example `demo/PROMPT.md`).

It sits in Frontend & Design. The repository describes itself as: Open-source platform for 3D AI agents. Turn text or a photo into a rigged, animated GLB avatar, give it an LLM brain, memory and a wallet, and embed it anywhere with one web… The licence is Apache-2.0.

When your agent uses it

Implementing 2D physics interactions with Matter.js
Including Engine/World setup
Render/Runner configuration
Adding bodies and constraints

Example prompts

“/matterjs”

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

Confirm environment (plain HTML, React, or canvas-only) and rendering approach (Matter.Render for debug vs custom renderer).
Provide a minimal Engine/World/Render/Runner setup and add bodies.
Add interactions (mouse constraint) or constraints only if requested.
Share cleanup steps for SPA or teardown scenarios.

What it can do on your machine

Read from SKILL.md and the folder at commit 238ef60. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are html and javascript).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Matterjs loads about 557 tokens when it runs. Until then it costs about 52 tokens; SKILL.md has 163 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~52
When it runs · the whole SKILL.md, loaded when a task matches: ~557

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from nirholas/three.ws at commit 238ef60, republished under its Apache-2.0 licence (© nirholas). 163 words, ~557 tokens.

Download SKILL.mdSave it as .claude/skills/matterjs/SKILL.md (or your agent's skills folder). This skill also uses 3 other files; get the full folder from GitHub.

name: matterjs
description: Use when implementing 2D physics interactions with Matter.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and scroll/interaction-friendly canvas scenes.

Matter.js Skill

Workflow

Confirm environment (plain HTML, React, or canvas-only) and rendering approach (Matter.Render for debug vs custom renderer).
Provide a minimal Engine/World/Render/Runner setup and add bodies.
Add interactions (mouse constraint) or constraints only if requested.
Share cleanup steps for SPA or teardown scenarios.

Minimal setup

html

<script>
  const { Engine, Render, Runner, Bodies, Composite } = Matter;

  const engine = Engine.create();

  const render = Render.create({
    element: document.body,
    engine: engine,
    options: {
      width: 800,
      height: 600,
      wireframes: false
    }
  });

  const runner = Runner.create();
  Runner.run(runner, engine);
  Render.run(render);

  const ground = Bodies.rectangle(400, 610, 810, 60, { isStatic: true });
  const box = Bodies.rectangle(400, 200, 80, 80);

  Composite.add(engine.world, [ground, box]);
</script>

Common patterns

Use Composite.add(engine.world, [...]) to add bodies to the world.
Use Render.create({ element, engine }) to create a canvas automatically, or pass a canvas you create yourself.
Set render.options.wireframes = false for solid rendering.
Use Runner.run(runner, engine) for a simple loop, or call Engine.update in your own loop if you need custom timing.

Mouse interaction (optional)

const { Mouse, MouseConstraint } = Matter;
const mouse = Mouse.create(render.canvas);
const mouseConstraint = MouseConstraint.create(engine, { mouse });
Composite.add(engine.world, mouseConstraint);
render.mouse = mouse;

Cleanup checklist (SPA)

Stop the runner with Runner.stop(runner).
Remove the render canvas from the DOM.
Clear engine and world if needed.

Questions to ask when specs are missing

What viewport size and scaling should the canvas use?
Are we using Matter.Render or a custom renderer?
Do you want mouse/touch drag interaction?
Should the simulation loop be paused when offscreen?

Files

SKILL.md and 3 other files in third_party/designcode-agent-skills/agent-skills/web-design/matterjs of nirholas/three.ws.

SKILL.md
demo/PROMPT.md
demo/index.html
demo/preview.jpg

Open the folder on GitHubat commit 238ef60

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in nirholas/three.ws, which our catalogue first saw on October 7, 2026.

MengTo/Skillsagent-skills/web-design/matterjs

Compare with similar skills

Matterjs next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Matterjs compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Matterjs this skillnirholas/three.ws	226	1 repos	~557	Automated safety check: Pass	Apache-2.0	today
Web Artifacts Builderanthropics/skills	180k	40 repos	~769	Automated safety check: Pass	Apache-2.0	2 days ago
React Doctormakeplane/plane	60k	12 repos	~657	Automated safety check: Pass	AGPL-3.0	yesterday
React Composition Patternsvercel-labs/openreview	1.7k	58 repos	~721	Automated safety check: Pass	MIT	7 mo ago
Impeccablebestofjs/bestofjs	3.1k	27 repos	~2.6k	Automated safety check: Pass	MIT	3 days ago
Figma Design System Builderwarpdotdev/warp	65k	2 repos	~4.4k	Automated safety check: Pass	AGPL-3.0	today

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Questions about Matterjs

What does Matterjs do?

A skill your agent uses when implementing 2D physics interactions with Matter.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and…. ws.js, including Engine/World setup, Render/Runner configuration, adding bodies and constraints, and scroll/interaction-friendly canvas scenes.

When should I use Matterjs?

Matterjs fits situations like: implementing 2D physics interactions with Matter.js; including Engine/World setup; render/Runner configuration; adding bodies and constraints.

How do I install Matterjs in Claude Code?

Run `npx skills add nirholas/three.ws --skill matterjs -a claude-code`. Or copy the skill folder (third_party/designcode-agent-skills/agent-skills/web-design/matterjs in nirholas/three.ws) into .claude/skills/matterjs in your project. Claude Code loads it when a task matches its description.

How do I install Matterjs in Codex?

Run `npx skills add nirholas/three.ws --skill matterjs -a codex`. Or copy the skill folder (third_party/designcode-agent-skills/agent-skills/web-design/matterjs in nirholas/three.ws) into .agents/skills/matterjs in your project. Codex loads it when a task matches its description.

Can I use Matterjs in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add nirholas/three.ws --skill matterjs -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/matterjs, .gemini/skills/matterjs, .github/skills/matterjs and .opencode/skills/matterjs in your project.

What does Matterjs need to run?

SKILL.md names no scripts, command-line tools or credentials: Matterjs is instructions for the agent only.

Does Matterjs access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Matterjs safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Matterjs use?

Matterjs is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Matterjs use?

About 557 tokens (SKILL.md is roughly 2.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Matterjs?

Skills that share tags, products or a category with Matterjs: Web Artifacts Builder (anthropics/skills, 180k stars), React Doctor (makeplane/plane, 60k stars), React Composition Patterns (vercel-labs/openreview, 1.7k stars) and Impeccable (bestofjs/bestofjs, 3.1k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Matterjs?

nirholas (a GitHub user) maintains it in nirholas/three.ws, which has 226 GitHub stars. The repository holds 165 skills in this directory. The repository was last updated on October 7, 2026.

Source: nirholas/three.ws on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Matterjs

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Matter.js Skill

Workflow

Minimal setup

Common patterns

Mouse interaction (optional)

Cleanup checklist (SPA)

Questions to ask when specs are missing

Files

Used in 1 other repository

Compare with similar skills

Similar skills

More from nirholas/three.ws

Related

Questions about Matterjs