performance

performance is a skill for Claude Code, Codex from cwklurks/ship-score. It costs 0 tokens per session (7,544 once invoked), scanned A, original, MIT.

A checklist for reviewing a website’s speed and resource use during a production-readiness audit. It includes checks such as whether images use an optimization solution instead of unprocessed image tags.

In plain words
What is it for?
Use it as part of a Ship Score audit to inspect image handling and other performance-related implementation details.
Why use it?
It helps identify implementation choices that can make pages heavier or slower before release. The excerpt does not identify all seven checks, so its full coverage cannot be described here.

Skill for Claude CodeCodex

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/cwklurks/ship-score/performance
Any agent
npx skills add cwklurks/ship-score --skill performance
Clone the repo
git clone --depth 1 https://github.com/cwklurks/ship-score

Made for: Claude Code, Codex.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/cwklurks/ship-score/performance.svg)](https://agentmods.dev/skills/cwklurks/ship-score/performance)
Your own site
<a href="https://agentmods.dev/skills/cwklurks/ship-score/performance"><img src="https://agentmods.dev/badge/skills/cwklurks/ship-score/performance.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,544 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.07544
Opus 5 $0.00000 $0.03772
Sonnet 5 $0.00000 $0.01509
Haiku 4.5 $0.00000 $0.00754

Measured 4d ago against content hash 8f3ffd99bd96, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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.

skills/performance/SKILL.md · 662 lines

How it starts

The opening of the file, as written. The whole thing — 662 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Category — Ship Score Sub-Skill

You are running the Performance category of a Ship Score production readiness audit. Follow every instruction below precisely. Do not add checks beyond the 7 defined here. Do not skip checks. Report exactly what you find.


Context You Receive

The orchestrator passes you:

Framework: [name] ([key])
Signals: [comma-separated detected features]
Root: [absolute path to project root]

Use the key value to select the correct framework-specific search patterns below. If the key is unknown, use the Generic/Vite patterns. Use the Root path for all file searches. If the project has a package.json, use it as the primary dependency manifest.


Checks

Run all 7 checks in order. For each check, follow the verification steps, determine the status, and record the evidence.


Check 1: Image Optimization

Severity: High

What to look for:

Usage of an image optimization solution (framework-provided component or third-party library) instead of raw <img> tags. Optimized images are served in modern formats (WebP/AVIF), resized on demand, and lazy-loaded -- reducing page weight by 30-80%.

Framework-specific verification:

Framework What to grep / check
Next.js (nextjs) Grep source files (.tsx, .jsx) for the next/image component. Pattern: from ['"]next/image['"] or from ["']next/image["'] or import Image near next/image. Also grep for <Image component usage: <Image\b.
Astro (astro) Grep source files (.astro, .tsx, .jsx) for astro:assets or @astrojs/image. Pattern: from ['"]astro:assets['"] or from ['"]@astrojs/image['"] or import.*Image.*from ['"]astro:assets['"]. Also grep for <Image or <Picture component usage.
Nuxt (nuxt) Grep source files (.vue) for <NuxtImg or <nuxt-img or @nuxt/image. Pattern: `<NuxtImg
SvelteKit (svelte) Grep source files (.svelte) for @sveltejs/enhanced-img or svelte-image. Pattern: `enhanced:img
Vite/Generic (vite, node, unknown) Grep package.json for image optimization libraries: sharp, imagemin, @squoosh/lib, vite-plugin-image-optimizer, vite-imagetools, unplugin-imagemin.

Read the full file on GitHub · 662 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.

  1. 4d ago First seen · 662 lines · 0 tokens per session scan A 8f3ffd99bd96

Subscribe to this mod's changes

performance is a skill published in the GitHub repository cwklurks/ship-score (1 stars, last pushed 5mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 7,544 tokens. 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.