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 metaspartan/cybara --skill web-game-developmentgit clone --depth 1 https://github.com/metaspartan/cybaraWrote 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/metaspartan/cybara/web-game-development)<a href="https://agentmods.dev/skills/metaspartan/cybara/web-game-development"><img src="https://agentmods.dev/badge/skills/metaspartan/cybara/web-game-development/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/metaspartan/cybara/web-game-development"><img src="https://agentmods.dev/badge/skills/metaspartan/cybara/web-game-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00049 | $0.00446 |
| Opus 5.5 | $0.00020 | $0.00178 |
| Sonnet 5.5 | $0.00010 | $0.00089 |
| Haiku 4.5 | $0.00005 | $0.00045 |
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 1mo 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.
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
- Run the repository's typecheck, lint, and unit tests.
- Build the production bundle and inspect asset warnings and output size.
- Launch the real app in a browser rather than testing a detached mock.
- Exercise boot, loading, primary controls, pause and resume, scene transitions, failure and restart, and responsive resize.
- Capture screenshots from representative gameplay states.
- Check console errors, failed network requests, frame pacing, memory growth, and WebGL warnings.
- 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.
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.
- 1mo ago First seen · 41 lines · 49 tokens per session scan A 628611223935
web-game-development is a skill published in the GitHub repository metaspartan/cybara (33 stars, last pushed 6d ago), licensed MIT. It adds 49 tokens to every session and 446 once invoked, about $0.0002 per session on Opus 5.5. 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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browser-recording
Record a browser flow as video/GIF evidence for animations, transitions and multi-step interactions a still screenshot cannot prove. Uses the project's Playwright via a bundled runner, then ffmpeg to mp4 + GIF. Use when asked to record a demo or GIF, or when a UI change involves motion.