web-game-development

web-game-development is a skill for Claude Code, Codex from metaspartan/cybara. It costs 49 tokens per session (446 once invoked), scanned A, original, MIT.

A workflow for building games that run in a web browser with JavaScript or TypeScript and engines such as Phaser, Three.js, Babylon.js, or PlayCanvas.

In plain words
What is it for?
It supports implementing, testing, and optimizing browser-based 2D and 3D games.
Why use it?
It helps handle browser-specific concerns such as keyboard and touch input, resizing, loading assets, pausing, and managing graphics resources.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Install

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.

agentmods
npx agentmods add skills/metaspartan/cybara/web-game-development
Any agent
npx skills add metaspartan/cybara --skill web-game-development
Clone the repo
git clone --depth 1 https://github.com/metaspartan/cybara

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for web-game-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/metaspartan/cybara/web-game-development.svg)](https://agentmods.dev/skills/metaspartan/cybara/web-game-development)
Your own site
<a href="https://agentmods.dev/skills/metaspartan/cybara/web-game-development"><img src="https://agentmods.dev/badge/skills/metaspartan/cybara/web-game-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 446 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.00446
Opus 5 $0.00024 $0.00223
Sonnet 5 $0.00010 $0.00089
Haiku 4.5 $0.00005 $0.00045

Measured 2d ago against content hash 628611223935, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

web-game-development scanned grade A with 0 findings 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 2d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/game-development/skills/web-game-development/SKILL.md · 41 lines

What it actually says

Web game development

Select the existing engine

Read package.json, source imports, renderer initialization, and asset loaders before editing. Preserve the chosen engine unless the user requests a migration.

  • Phaser: scene-driven 2D games, sprites, tilemaps, cameras, and arcade or matter physics.
  • Three.js: imperative 3D scene, camera, renderer, loaders, and render-loop control.
  • React Three Fiber: React-owned composition around Three.js with explicit per-frame boundaries.
  • Babylon.js: engine-managed 3D scenes, loaders, physics, GUI, and WebGPU or WebGL paths.
  • PlayCanvas: component and entity workflows using the project's selected editor or engine package.

Implementation rules

  • Use Bun for dependency and script commands.
  • Keep simulation state separate from rendering objects and DOM UI.
  • Map keyboard, pointer, touch, and controller input into explicit game actions.
  • Handle resize, device pixel ratio, pause, visibility changes, audio unlock, and WebGL context loss.
  • Keep text-heavy HUD and menus accessible and responsive.
  • Bound texture resolution, geometry, particles, post-processing, and retained resources.
  • Dispose GPU resources and listeners when scenes or components unload.

Verification

  1. Run the repository's typecheck, lint, and unit tests.
  2. Build the production bundle and inspect asset warnings and output size.
  3. Launch the real app in a browser rather than testing a detached mock.
  4. Exercise boot, loading, primary controls, pause and resume, scene transitions, failure and restart, and responsive resize.
  5. Capture screenshots from representative gameplay states.
  6. Check console errors, failed network requests, frame pacing, memory growth, and WebGL warnings.
  7. Repeat touch and safe-area checks when mobile browsers are supported.

Completion criteria

Report the engine, browser and viewport tested, player path, production build result, console state, screenshots, and measured performance limitations.

Changes

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.

  1. 2d ago First seen · 41 lines · 49 tokens per session scan A 628611223935

Subscribe to this mod's changes

web-game-development is a skill published in the GitHub repository metaspartan/cybara (28 stars, last pushed today), licensed MIT. It adds 49 tokens to every session and 446 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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