React Doctor
makeplane/plane
Scans React code for lint, accessibility, bundle size and architecture issues, reports a health score and checks that changes do not lower it.
Performance specialist perspective for the weekly review. An agent skill from mizchi/skills.
Install Performance Expert
$ npx skills add mizchi/skills --skill performance-expert -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install mizchi/skills performance-expert --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/performance-expert .claude/skills/performance-expert && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .claude/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/mizchi/skills/tree/main/performance-expertType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add mizchi/skills --skill performance-expert -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install mizchi/skills performance-expert --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/performance-expert .agents/skills/performance-expert && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .agents/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mizchi/skills --skill performance-expert -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install mizchi/skills performance-expert --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/performance-expert .cursor/skills/performance-expert && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .cursor/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/mizchi/skills.git --path performance-expert--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add mizchi/skills --skill performance-expert -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install mizchi/skills performance-expert --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/performance-expert .gemini/skills/performance-expert && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .gemini/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install mizchi/skills performance-expertInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add mizchi/skills --skill performance-expert -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/performance-expert .github/skills/performance-expert && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .github/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mizchi/skills --skill performance-expert -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install mizchi/skills performance-expert --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mizchi/skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/performance-expert .opencode/skills/performance-expert && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "performance-expert" agent skill from https://github.com/mizchi/skills/tree/main/performance-expert into .opencode/skills/performance-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-expert", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
performance-expert- GitHub stars
- 356
- Token cost
- ~895 tokens
- SKILL.md length
- 423 words
- Files
- 2
- Skills in repo
- 69
- Repo updated
- First seen
- Licence
- None found
At a glance
Performance specialist perspective for the weekly review. An agent skill from mizchi/skills.
- Works in 4 steps: Read… → Read raw/lighthouse.json if it exists,… → Read raw/deps.json and… → …
- Tasks that involve Web performance
- SKILL.md covers Procedure, Output, Core Web Vitals Targets and Performance Degradation…, plus 3 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Performance Expert is an agent skill from mizchi/skills. Performance specialist perspective for the weekly review. Focuses on bundle size, LCP / CLS / INP, avoidable re-work, image and font optimization. Reads audit-bundle and audit-lighthouse raw output when available.
Its SKILL.md is about 900 tokens, which your agent loads only when the skill is triggered. The skill folder holds 1 other file (for example `README.md`).
It sits in Frontend & Design, covering Web performance. The repository describes itself as: Agent skills by mizchi, distributed via APM.
When your agent uses it
- Tasks that involve Web performance
Example prompts
- “/performance-expert”
Workflow steps
4 steps, taken from the first numbered list in SKILL.md.
- Read /.frontend-review/report/latest/raw/bundle.json if it exists, else note "C1 not adopted".
- Read raw/lighthouse.json if it exists, else note "C2 not adopted".
- Read raw/deps.json and raw/similarity.json — heavy duplication or dead dependencies inflate bundles.
- If neither C1 nor C2 is adopted, still comment on what signals are visible from the other scripts: duplication, unused dependencies, heavy…
What it can do on your machine
Read from SKILL.md and the folder at commit 62f5808. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Performance Expert loads about 895 tokens when it runs. Until then it costs about 58 tokens; SKILL.md has 423 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Without a licence we can't republish the file, so here is its outline and opening line. It has 423 words (~895 tokens).
“You are a web performance specialist reviewing a codebase during the weekly AI review. You care about:”
- name
- performance-expert
Files
SKILL.md and 1 other file in performance-expert of mizchi/skills.
- SKILL.md
- README.md
Open the folder on GitHubat commit 62f5808
Compare with similar skills
Performance Expert next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Performance Expert this skillmizchi/skills | 356 | — | ~895 | Automated safety check: Pass | None | |
| React Doctormakeplane/plane | 60k | 12 repos | ~657 | Automated safety check: Pass | AGPL-3.0 | |
| Fixing Motion Performanceibelick/ui-skills | 9.4k | 5 repos | ~1.4k | Automated safety check: Pass | MIT | |
| GSAP Performance Tuninggreensock/gsap-skills | 16k | 4 repos | ~1k | Automated safety check: Pass | MIT | |
| React Frontend Development Guidelinesdiet103/claude-code-infrastructure-showcase | 10k | 2 repos | ~2.9k | Automated safety check: Pass | MIT | |
| Web Quality Auditaddyosmani/web-quality-skills | 2.9k | — | ~2.6k | Automated safety check: Pass | MIT |
Similar skills
Fixing Motion Performance
ibelick/ui-skills
Audits and fixes web animation performance: layout thrashing, work that belongs on the compositor, scroll-linked motion and costly blur effects.
GSAP Performance Tuning
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Guides the agent to keep GSAP animations smooth by animating transforms and opacity, batching DOM reads and writes, and avoiding layout-heavy properties.
React Frontend Development Guidelines
diet103/claude-code-infrastructure-showcase
Guidelines for React 18 and TypeScript apps covering Suspense data fetching, lazy loading, feature folders, MUI v7 styling, TanStack Router and performance.
Web Quality Audit
addyosmani/web-quality-skills
Run an evidence-led web quality audit covering performance, accessibility, SEO, best practices, and agentic browsing.
SEO Google
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Google SEO APIs: Search Console (Search Analytics, URL Inspection, Sitemaps), PageSpeed Insights v5, CrUX field data with 25-week history, Indexing API v3, and GA4 organic traffic.
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Related
Categories
Questions about Performance Expert
What does Performance Expert do?
Performance specialist perspective for the weekly review. An agent skill from mizchi/skills. Performance Expert is an agent skill from mizchi/skills. Performance specialist perspective for the weekly review.
When should I use Performance Expert?
Performance Expert fits situations like: tasks that involve Web performance.
How do I install Performance Expert in Claude Code?
Run `npx skills add mizchi/skills --skill performance-expert -a claude-code`. Or copy the skill folder (performance-expert in mizchi/skills) into .claude/skills/performance-expert in your project. Claude Code loads it when a task matches its description.
How do I install Performance Expert in Codex?
Run `npx skills add mizchi/skills --skill performance-expert -a codex`. Or copy the skill folder (performance-expert in mizchi/skills) into .agents/skills/performance-expert in your project. Codex loads it when a task matches its description.
Can I use Performance Expert in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mizchi/skills --skill performance-expert -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/performance-expert, .gemini/skills/performance-expert, .github/skills/performance-expert and .opencode/skills/performance-expert in your project.
What does Performance Expert need to run?
SKILL.md names no scripts, command-line tools or credentials: Performance Expert is instructions for the agent only.
Does Performance Expert access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Performance Expert safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Performance Expert use?
No licence was found for Performance Expert or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Performance Expert use?
About 895 tokens (SKILL.md is roughly 3.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Performance Expert?
Skills that share tags, products or a category with Performance Expert: React Doctor (makeplane/plane, 60k stars), Fixing Motion Performance (ibelick/ui-skills, 9.4k stars), GSAP Performance Tuning (greensock/gsap-skills, 16k stars) and React Frontend Development Guidelines (diet103/claude-code-infrastructure-showcase, 10k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Performance Expert?
mizchi (a GitHub user) maintains it in mizchi/skills, which has 356 GitHub stars. The repository holds 69 skills in this directory. The repository was last updated on October 2, 2026.
Source: mizchi/skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.