frontend-review-performance

frontend-review-performance is a skill for Claude Code, Codex from mizchi/skills. It costs 51 tokens per session (1,481 once invoked), scanned A, original, no licence file.

A checklist for finding slow rendering in React, a JavaScript library for building user interfaces. It uses the React Profiler, a tool that shows which parts of an interface take time to update.

In plain words
What is it for?
Use it to review memoization, useCallback, useMemo, virtual scrolling, useTransition, useDeferredValue, and the separation of canvas or WebGL graphics from normal interface rendering.
Why use it?
It helps explain why a page feels slow and checks whether optimization features are being used correctly. It also covers large lists, deferred updates, and graphics-heavy interfaces.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to review memoization, useCallback, useMemo, virtual scrolling, useTransition, useDeferredValue, and the separation of canvas or WebGL graphics from normal interface rendering.

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

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 frontend-review-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/mizchi/skills/review-performance.svg)](https://agentmods.dev/skills/mizchi/skills/review-performance)
Your own site
<a href="https://agentmods.dev/skills/mizchi/skills/review-performance"><img src="https://agentmods.dev/badge/skills/mizchi/skills/review-performance.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,481 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 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 5.1 $0.00051 $0.01481
Opus 5 $0.00026 $0.00740
Sonnet 5 $0.00010 $0.00296
Haiku 4.5 $0.00005 $0.00148

Measured 9d ago against content hash e6e642009f6e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

frontend-review-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 9d 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.

frontend/review-performance/SKILL.md · 156 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

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. 9d ago First seen · 156 lines · 51 tokens per session scan A e6e642009f6e

Subscribe to this mod's changes

frontend-review-performance is a skill published in the GitHub repository mizchi/skills (325 stars, last pushed 1mo ago), with no licence file. It adds 51 tokens to every session and 1,481 once invoked, about $0.0003 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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