AG Kit is a toolkit that gives Google Antigravity coding agents a structured workspace with rules, skills, specialist agents, workflows, persistent memory, orchestration, MCP guidance, and a safety hook. It is for building and operating agent workflows in Antigravity, and its catalogue entries provide parts of that workspace contract.
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 agentmods add skills/vudovn/ag-kit/web-gamesnpx skills add vudovn/ag-kit --skill web-gamesgit clone --depth 1 https://github.com/vudovn/ag-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/vudovn/ag-kit/web-games)<a href="https://agentmods.dev/skills/vudovn/ag-kit/web-games"><img src="https://agentmods.dev/badge/skills/vudovn/ag-kit/web-games.svg" alt="Measured on agentmods" 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 | $0.00020 | $0.00782 |
| Opus 5 | $0.00010 | $0.00391 |
| Sonnet 5 | $0.00004 | $0.00156 |
| Haiku 4.5 | $0.00002 | $0.00078 |
Grade A, and why
web-games 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 5d 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.
Copies of this mod
8 near-identical copies found in the catalogue:
- web-games — 97% identical, 4 lines differ
- web-games — 97% identical, 4 lines differ
- web-games — 97% identical, 4 lines differ
- web-games — 97% identical, 4 lines differ
- web-games — 97% identical, 4 lines differ
- web-games — 92% identical, 7 lines differ
- web-games — 92% identical, 5 lines differ
- web-games — 84% identical, 13 lines differ
How it starts
The opening of the file, as written. The whole thing — 151 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web Browser Game Development
Framework selection and browser-specific principles.
1. Framework Selection
Decision Tree
What type of game?
│
├── 2D Game
│ ├── Full game engine features? → Phaser
│ └── Raw rendering power? → PixiJS
│
├── 3D Game
│ ├── Full engine (physics, XR)? → Babylon.js
│ └── Rendering focused? → Three.js
│
└── Hybrid / Canvas
└── Custom → Raw Canvas/WebGL
Comparison
| Framework | Type | Best For |
|---|---|---|
| Phaser 4 | 2D | Full game features |
| PixiJS 8 | 2D | Rendering, UI |
| Three.js | 3D | Visualizations, lightweight |
| Babylon.js 7 | 3D | Full engine, XR |
2. WebGPU Adoption
Browser Support
| Browser | Support |
|---|---|
| Chrome | ✅ Since v113 |
| Edge | ✅ Since v113 |
| Firefox | ✅ Since v131 |
| Safari | ✅ Since 18.0 |
| Total | ~73% global |
Decision
- New projects: Use WebGPU with WebGL fallback
- Legacy support: Start with WebGL
- Feature detection: Check
navigator.gpu
3. Performance Principles
Browser Constraints
| Constraint | Strategy |
|---|---|
| No local file access | Asset bundling, CDN |
| Tab throttling | Pause when hidden |
| Mobile data limits | Compress assets |
| Audio autoplay | Require user interaction |
Optimization Priority
- Asset compression - KTX2, Draco, WebP
- Lazy loading - Load on demand
- Object pooling - Avoid GC
- Draw call batching - Reduce state changes
- Web Workers - Offload heavy computation
4. Asset Strategy
Compression Formats
| Type | Format |
|---|---|
| Textures | KTX2 + Basis Universal |
| Audio | WebM/Opus (fallback: MP3) |
| 3D Models | glTF + Draco/Meshopt |
Loading Strategy
| Phase | Load |
|---|---|
| Startup | Core assets, <2MB |
| Gameplay | Stream on demand |
| Background | Prefetch next level |
5. PWA for Games
Benefits
- Offline play
- Install to home screen
- Full screen mode
- Push notifications
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.
- 5d ago First seen · 151 lines · 20 tokens per session scan A 1431bf2f5a70
web-games is a skill published in the GitHub repository vudovn/ag-kit (8,170 stars, last pushed 5d ago), licensed MIT. It adds 20 tokens to every session and 782 once invoked, about $0.0001 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 2026-08-30.
Other skills, from other repositories
gameobject-component-destroy
Destroy one or more Components from a target GameObject. Missing (null) components are skipped — they cannot be destroyed. Use 'gameobject-find' and 'gameobject-component-get' to identify the components first.
unity-version-split
Split a C# file into Unity 6.5+ and pre-Unity 6.5 variants. Use when a file needs different implementations for different Unity versions due to API changes (e.g., EntityId vs int, GetEntityId vs GetInstanceID).
unity-addressables
Manage Addressables groups, entries, profiles and content builds (com.unity.addressables, reflection-based).
playtest-report
Generates a structured playtest report template or analyzes existing playtest notes into a structured format. Use this to standardize playtest feedback collection and analysis.
unity-manual-component
Manually add, configure, reorder, and copy components on GameObjects using Unity Editor UI. For one-off Inspector workflows that do not need REST automation.
godot-signals-groups
Build event-driven, decoupled Godot 4.7 gameplay with signals and node groups: declare and emit custom signals, connect with Callables (incl. bind/one-shot), and broadcast to many nodes via groups and callgroup. Use when wiring node communication in a Godot project, replacing tight references with signals…