performance-profiling

performance-profiling is a skill for Claude Code from bugrabilge/bilge-development-kit. It costs 17 tokens per session (757 once invoked), scanned A, a copy of performance-profiling, MIT.

A guide to measuring software performance before changing it, finding the bottleneck, applying a focused fix, and measuring again.

In plain words
What is it for?
Use it to investigate page loading, browser responsiveness, bundle size, runtime, memory, and network performance.
Why use it?
It helps prevent guesses and optimisations that do not improve the actual problem.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to investigate page loading, browser responsiveness, bundle size, runtime, memory, and network performance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bugrabilge/bilge-development-kit/performance-profiling
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 bugrabilge/bilge-development-kit --skill performance-profiling
Clone the repo
git clone --depth 1 https://github.com/bugrabilge/bilge-development-kit

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-profiling

README.md
[![agentmods](https://agentmods.dev/badge/skills/bugrabilge/bilge-development-kit/performance-profiling/github.svg)](https://agentmods.dev/skills/bugrabilge/bilge-development-kit/performance-profiling)
Your own site
<a href="https://agentmods.dev/skills/bugrabilge/bilge-development-kit/performance-profiling"><img src="https://agentmods.dev/badge/skills/bugrabilge/bilge-development-kit/performance-profiling/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-profiling

Your own site · 80×15
<a href="https://agentmods.dev/skills/bugrabilge/bilge-development-kit/performance-profiling"><img src="https://agentmods.dev/badge/skills/bugrabilge/bilge-development-kit/performance-profiling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 17 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 757 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 91% copy Near-identical to another mod 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 $0.00017 $0.00757
Opus 5 $0.00009 $0.00378
Sonnet 5 $0.00003 $0.00151
Haiku 4.5 $0.00002 $0.00076

Measured 5d ago against content hash 5e58efdd8fd9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

performance-profiling 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/lighthouse_audit.py), 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.

Origin

This is a copy

91% identical to performance-profiling — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/performance-profiling/SKILL.md · 144 lines

How it starts

The opening of the file, as written. The whole thing — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Profiling

Measure, analyze, optimize - in that order.

🔧 Runtime Scripts

Execute these for automated profiling:

Script Purpose Usage
scripts/lighthouse_audit.py Lighthouse performance audit python scripts/lighthouse_audit.py https://example.com

1. Core Web Vitals

Targets

Metric Good Poor Measures
LCP < 2.5s > 4.0s Loading
INP < 200ms > 500ms Interactivity
CLS < 0.1 > 0.25 Stability

When to Measure

Stage Tool
Development Local Lighthouse
CI/CD Lighthouse CI
Production RUM (Real User Monitoring)

2. Profiling Workflow

The 4-Step Process

1. BASELINE → Measure current state
2. IDENTIFY → Find the bottleneck
3. FIX → Make targeted change
4. VALIDATE → Confirm improvement

Profiling Tool Selection

Problem Tool
Page load Lighthouse
Bundle size Bundle analyzer
Runtime DevTools Performance
Memory DevTools Memory
Network DevTools Network

3. Bundle Analysis

What to Look For

Issue Indicator
Large dependencies Top of bundle
Duplicate code Multiple chunks
Unused code Low coverage
Missing splits Single large chunk

Optimization Actions

Finding Action
Big library Import specific modules
Duplicate deps Dedupe, update versions
Route in main Code split
Unused exports Tree shake

4. Runtime Profiling

Performance Tab Analysis

Pattern Meaning
Long tasks (>50ms) UI blocking
Many small tasks Possible batching opportunity
Layout/paint Rendering bottleneck
Script JavaScript execution

Memory Tab Analysis

Pattern Meaning
Growing heap Possible leak
Large retained Check references
Detached DOM Not cleaned up

Read the full file on GitHub · 144 lines

Files

What ships with it

1 file 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. 5d ago First seen · 144 lines · 17 tokens per session scan A 5e58efdd8fd9

Subscribe to this mod's changes

performance-profiling is a skill published in the GitHub repository bugrabilge/bilge-development-kit (10 stars, last pushed 4mo ago), licensed MIT. It adds 17 tokens to every session and 757 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to performance-profiling, differing in 2 lines, and is treated as a copy.

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