performance-profiler

performance-profiler is a skill for Claude Code from EliasOulkadi/shokunin. It costs 118 tokens per session (2,842 once invoked), scanned A, original, MIT.

A web and backend performance analysis process covering loading speed, responsiveness, layout stability, code size, server work, database queries, caching, and delivery networks. Core Web Vitals are standard measures of how quickly and smoothly a page works for users.

In plain words
What is it for?
Use it to run Lighthouse audits, inspect Core Web Vitals, analyze bundles, profile Node.js or Python backends, find repeated database queries, and check performance budgets.
Why use it?
It helps identify what makes an application slow or unresponsive instead of relying on guesswork.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions OpenCode.

Good fit Use it to run Lighthouse audits, inspect Core Web Vitals, analyze bundles, profile Node.js or Python backends, find repeated database queries, and check performance budgets.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/eliasoulkadi/shokunin/performance-profiler
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.

Any agent
npx skills add EliasOulkadi/shokunin --skill performance-profiler
Clone the repo
git clone --depth 1 https://github.com/EliasOulkadi/shokunin

Made for: Claude Code.

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 performance-profiler

README.md
[![agentmods](https://agentmods.dev/badge/skills/eliasoulkadi/shokunin/performance-profiler/github.svg)](https://agentmods.dev/skills/eliasoulkadi/shokunin/performance-profiler)
Your own site
<a href="https://agentmods.dev/skills/eliasoulkadi/shokunin/performance-profiler"><img src="https://agentmods.dev/badge/skills/eliasoulkadi/shokunin/performance-profiler/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.

agentmods 80×15 button for performance-profiler

Your own site · 80×15
<a href="https://agentmods.dev/skills/eliasoulkadi/shokunin/performance-profiler"><img src="https://agentmods.dev/badge/skills/eliasoulkadi/shokunin/performance-profiler.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,842 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 6 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 55
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 56
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 238
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 192
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 195
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 239
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
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 $0.00118 $0.02842
Opus 5 $0.00059 $0.01421
Sonnet 5 $0.00024 $0.00568
Haiku 4.5 $0.00012 $0.00284

Measured 10d ago against content hash c2540d162410, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

performance-profiler 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 10d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/audit-lighthouse.ps1, scripts/profile-node.ps1), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.pack/skills/performance-profiler/SKILL.md · 305 lines

How it starts

The opening of the file, as written. The whole thing — 305 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Profiler

Find and fix performance issues from frontend to backend. Based on Google Core Web Vitals, Lighthouse, Chrome DevTools, and production patterns from WebPageTest and clinic.js.

Sub-Commands

Command Description
audit Run comprehensive performance audit (frontend + backend)
vitals Audit Core Web Vitals specifically (LCP, INP, CLS, TBT)
lcp Optimize Largest Contentful Paint
inp Fix Interaction to Next Paint (long tasks)
bundle Analyze bundle size and split strategy
backend Profile Node.js/Python backend performance
budget Set and verify performance budgets

Workflow

Step 1: Run Lighthouse audit (exact command)

npx lighthouse https://example.com --preset=desktop --output=html --output-path=./lighthouse-report.html
npx lighthouse https://example.com --preset=desktop --output=json --output-path=./lighthouse.json

Target scores:

Metric Target Severity if missed
Performance > 90 Critical
LCP (Largest Contentful Paint) < 2.5s Critical
INP (Interaction to Next Paint) < 200ms Critical
CLS (Cumulative Layout Shift) < 0.1 Critical
TBT (Total Blocking Time) < 200ms High
FCP (First Contentful Paint) < 1.8s Medium
Speed Index < 3.4s Medium

Step 2: Fix Core Web Vitals

LCP optimization (exact fixes)
<!-- 1. Preload LCP image -->
<link rel="preload" as="image" href="hero.webp" fetchpriority="high">

<!-- 2. LCP image: no lazy loading -->
<img src="hero.webp" width="1200" height="600" fetchpriority="high" alt="">

<!-- 3. Inline critical CSS in <head> -->
<style>
  .hero { display: grid; min-height: 100dvh; }
  .hero img { width: 100%; height: auto; aspect-ratio: 2/1; }
</style>

<!-- 4. Defer non-critical CSS -->
<link rel="preload" href="styles.css" as="style" onload="this.onload=null;this.rel='stylesheet'">

<!-- 5. Self-host fonts with font-display: swap -->
@font-face {
  font-family: 'Geist';
  src: url('/fonts/geist.woff2') format('woff2');
  font-display: swap;
}

Read the full file on GitHub · 305 lines

Files

What ships with it

4 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.

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. 10d ago First seen · 305 lines · 118 tokens per session scan A c2540d162410

Subscribe to this mod's changes

performance-profiler is a skill published in the GitHub repository EliasOulkadi/shokunin (113 stars, last pushed 1mo ago), licensed MIT. It adds 118 tokens to every session and 2,842 once invoked, about $0.0006 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.