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/playcanvas/create-playcanvas/build-appnpx skills add playcanvas/create-playcanvas --skill build-appgit clone --depth 1 https://github.com/playcanvas/create-playcanvasWrote 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/playcanvas/create-playcanvas/build-app)<a href="https://agentmods.dev/skills/playcanvas/create-playcanvas/build-app"><img src="https://agentmods.dev/badge/skills/playcanvas/create-playcanvas/build-app.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 5.1 | $0.00054 | $0.00466 |
| Opus 5 | $0.00027 | $0.00233 |
| Sonnet 5 | $0.00011 | $0.00093 |
| Haiku 4.5 | $0.00005 | $0.00047 |
Grade A, and why
build-app 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 6d 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
1 near-identical copy found in the catalogue:
- build-app — 100% identical, 12 lines differ
How it starts
The opening of the file, as written. The whole thing — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Build an Engine application
Read package.json and the application entry point before changing its structure. Choose the
authoring surface from the code being edited:
- read references/react.md for
@playcanvas/reactimports and JSX; - read references/web-components.md for
pc-*elements or@playcanvas/web-componentsimports; - read references/direct-engine.md for direct
playcanvasbootstrap code without a wrapper-owned lifecycle.
Installed dependencies alone are insufficient when a project contains more than one surface. Preserve the surface that owns the current entry point and lifecycle.
Render at an intentional density
PlayCanvas defaults graphicsDevice.maxPixelRatio to 1 for predictable fill-rate cost. In a
quality-oriented browser app, set it deliberately after the application exists and before its
initial automatic resize; Math.min(window.devicePixelRatio, 2) is a practical high-DPI starting
point. Keep 1 only as a measured performance decision, and resize the canvas again after changing
the value.
Verify the real backbuffer in a browser: for automatic resolution, canvas.width / canvas.clientWidth
and the height ratio should match the chosen pixel ratio. CSS dimensions and a screenshot filepath
do not prove rendering density.
For every surface:
- verify version-sensitive APIs against installed declarations or source;
- keep one owner for application creation, assets, entities, update callbacks, and teardown;
- prefer the surface's declarative or lifecycle primitives before reaching into the Engine;
- put per-entity and per-frame behavior in an Engine
Scriptwhen page or view state is not its natural owner; - clamp the per-frame delta before advancing gameplay, timers, physics, or a state clock, so a backgrounded tab or a slow frame cannot inject one large integration step;
- clean up external events and resources in the lifecycle that created them.
What ships with it
3 files 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.
- 6d ago First seen · 42 lines · 54 tokens per session scan A 36cb0b469f56
build-app is a skill published in the GitHub repository playcanvas/create-playcanvas (53 stars, last pushed yesterday), licensed MIT. It adds 54 tokens to every session and 466 once invoked, about $0.0003 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.
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