What is performance-audit?

A measurement-first guide for finding performance problems in code editors, game previews, and running games.

Use it to reproduce jank, measure frame time and FPS, inspect draw calls and allocations, and fix costly scene or rendering work.

It replaces guesses about slow code with a measured baseline, so changes target the part causing frame drops, memory growth, rerendering, or excessive drawing.

How andvolodko/html5-game-editor configures Cursor

Reuse

Borrowing it

Nothing to install: this file belongs to andvolodko/html5-game-editor. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/andvolodko/html5-game-editor/master/.cursor/skills/performance-audit/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/andvolodko/html5-game-editor

Made for: Cursor.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/performance-audit/github.svg)](https://agentmods.dev/skills/andvolodko/html5-game-editor/performance-audit)

Your own site

<a href="https://agentmods.dev/skills/andvolodko/html5-game-editor/performance-audit"><img src="https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/performance-audit/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/andvolodko/html5-game-editor/performance-audit"><img src="https://agentmods.dev/badge/skills/andvolodko/html5-game-editor/performance-audit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,526 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00060	$0.01526
Opus 5.5	$0.00024	$0.00610
Sonnet 5.5	$0.00012	$0.00305
Haiku 4.5	$0.00006	$0.00153

Measured 2mo ago against content hash 55f7563c346e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

performance-audit 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 2mo 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.

.cursor/skills/performance-audit/SKILL.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Audit

Measurement-first workflow. Do not change architecture on a hunch.

Architecture constraints: docs/architecture.md (Performance) and .cursor/rules/core.mdc. Editor viewport rules: .cursor/rules/editor-ui.mdc.

When to use this skill

Editor Scene/Preview jank, hitching, or memory growth.
Game runtime FPS drops, GC spikes, or high Performance Meter stats.
A change is suspected of rebuilding the whole scene graph or re-rendering React every ticker frame.
User asks to “optimize” without a measured hot path.

Do not use this to sprinkle caches through unrelated modules.

Before changing code

Reproduce the slow case with a concrete scene (demo games/editor-features-demo/assets/scenes/perfomance-test.json exists for load; also hybrid.json / world3d.json / Spine scenes).
Identify the hot path (editor viewport vs Preview/GameRuntime vs Asset Browser vs Inspector).
Establish a baseline (FPS, frame time, draw calls, display object counts, allocations). Guessing is not a baseline.
Read the existing sync model: EditorViewportController is incremental; SceneRenderer.clear is load/recovery only (packages/scene/src/scene-renderer.ts).

This repo does not use Zustand. Editor UI subscribes via useEditorState → editor.getStoreVersion() (apps/editor/src/hooks/useEditorState.ts).

Audit workflow

reproduce
→ identify hot path
→ establish baseline
→ inspect architecture
→ implement smallest safe optimization
→ verify behavior
→ compare before/after
→ add regression test where practical

1. Reproduce and classify

Surface	Typical cost
Editor Scene	Pixi/Three update + gizmos + selection chrome
Preview / game	`GameRuntime.tick` → scripts `update` → `renderer.render`
React shell	`editor.subscribe` notifying every panel
Assets	import, thumbnail decode, preview hosts
Persistence	`JSON.stringify` of the whole scene (save, not per frame)

Read the full file on GitHub · 127 lines

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.

2mo ago First seen · 127 lines · 60 tokens per session scan A 55f7563c346e

Subscribe to this mod's changes

performance-audit is a skill published in the GitHub repository andvolodko/html5-game-editor (14 stars, last pushed 1mo ago), licensed MIT. It adds 60 tokens to every session and 1,526 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 2026-08-31.

2d 3d Debugging Game development editor game-development game-editor game-engine

performance-audit next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
performance-auditandvolodko/html5-game-editor	Skill	14	1mo ago	MIT	A	60	Cursor
tune-performanceSummerEngine/summer-engine-agent	Skill	59	1mo ago	MIT	A	94	Claude Code
diagnosing-perf-regressionsSummerEngine/summer-engine-agent	Skill	59	1mo ago	MIT	A	58	Claude Code
debugging-game-feelSummerEngine/summer-engine-agent	Skill	59	1mo ago	MIT	A	53	Claude Code
performance-optimizationgamedev-skills/awesome-gamedev-agent-skills	Skill	6.9k	9d ago	Apache-2.0	A	121	Claude Code
godot-debuggingjame581/GodotPrompter	Skill	929	5d ago	MIT	A	26	Claude Code
beehavejame581/GodotPrompter	Skill	929	5d ago	MIT	A	35	Claude Code

html5-game-editor: Skill for Cursor