analyze-performance

analyze-performance is a skill for Claude Code, Codex from wasabeef/claude-code-cookbook. It costs 46 tokens per session (1,763 once invoked), scanned A, original, no licence file.

A web-performance analysis helper based on Core Web Vitals, which are measurements of loading speed, responsiveness, and visual stability.

In plain words
What is it for?
Use it to analyze page speed, review Core Web Vitals, improve LCP—the time until the main content appears—and find performance issues.
Why use it?
It helps identify speed and user-experience problems that may make a web page feel slow or unstable.

Skill for Claude CodeCodex

Part of the cook-en plugin — 18 skills, 39 commands shipped together

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.

agentmods
npx agentmods add skills/wasabeef/claude-code-cookbook/analyze-performance
Any agent
npx skills add wasabeef/claude-code-cookbook --skill analyze-performance
Clone the repo
git clone --depth 1 https://github.com/wasabeef/claude-code-cookbook

Made for: Claude Code, Codex.

Or install cook-en, the plugin that ships this one along with the rest of its 18 skills, 39 commands.

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 analyze-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/wasabeef/claude-code-cookbook/analyze-performance.svg)](https://agentmods.dev/skills/wasabeef/claude-code-cookbook/analyze-performance)
Your own site
<a href="https://agentmods.dev/skills/wasabeef/claude-code-cookbook/analyze-performance"><img src="https://agentmods.dev/badge/skills/wasabeef/claude-code-cookbook/analyze-performance.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,763 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00046 $0.01763
Opus 5 $0.00023 $0.00881
Sonnet 5 $0.00009 $0.00353
Haiku 4.5 $0.00005 $0.00176

Measured 4d ago against content hash 0b4955d5cf49, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

analyze-performance 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 4d 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.

plugins/en/skills/analyze-performance/SKILL.md · 178 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 4d ago First seen · 178 lines · 46 tokens per session scan A 0b4955d5cf49

Subscribe to this mod's changes

analyze-performance is a skill published in the GitHub repository wasabeef/claude-code-cookbook (1,132 stars, last pushed 4mo ago), with no licence file. It adds 46 tokens to every session and 1,763 once invoked, about $0.0002 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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