React Best Practices
ryokun6/ryos
React performance optimization guidelines from Vercel Engineering (vercel-labs/agent-skills).
Performance profiling principles. An agent skill from xenitV1/Antigravity-Workflows.
Install Performance Profiling
$ npx skills add xenitV1/Antigravity-Workflows --skill performance-profiling -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install xenitV1/Antigravity-Workflows performance-profiling --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/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/performance-profiling .claude/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .claude/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profilingType 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 xenitV1/Antigravity-Workflows --skill performance-profiling -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install xenitV1/Antigravity-Workflows performance-profiling --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/performance-profiling .agents/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .agents/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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 xenitV1/Antigravity-Workflows --skill performance-profiling -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install xenitV1/Antigravity-Workflows performance-profiling --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/performance-profiling .cursor/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .cursor/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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/xenitV1/Antigravity-Workflows.git --path skills/performance-profiling--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 xenitV1/Antigravity-Workflows --skill performance-profiling -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install xenitV1/Antigravity-Workflows performance-profiling --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/performance-profiling .gemini/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .gemini/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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 xenitV1/Antigravity-Workflows performance-profilingInstalls 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 xenitV1/Antigravity-Workflows --skill performance-profiling -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/performance-profiling .github/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .github/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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 xenitV1/Antigravity-Workflows --skill performance-profiling -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install xenitV1/Antigravity-Workflows performance-profiling --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/xenitV1/Antigravity-Workflows.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/performance-profiling .opencode/skills/performance-profiling && 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-profiling" agent skill from https://github.com/xenitV1/Antigravity-Workflows/tree/main/skills/performance-profiling into .opencode/skills/performance-profiling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "performance-profiling", 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-profiling- GitHub stars
- 130
- Used in
- 7 other repos
- Token cost
- ~772 tokens
- SKILL.md length
- 278 words
- Files
- 2 (incl. scripts)
- Skills in repo
- 42
- Repo updated
- First seen
- Licence
- MIT
At a glance
Performance profiling principles. An agent skill from xenitV1/Antigravity-Workflows.
- Works in 7 steps: Core Web Vitals → Profiling Workflow → Bundle Analysis → …
- Tasks that involve Performance optimization
- SKILL.md covers 🔧 Runtime Scripts, 1. Core Web Vitals, 2. Profiling Workflow and 3. Bundle Analysis, plus 4 more sections
- Runs Python scripts from its folder; calls python
What it does
Performance Profiling is an agent skill from xenitV1/Antigravity-Workflows. Performance profiling principles. Measurement, analysis, and optimization techniques.
Its SKILL.md is about 770 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including scripts (for example `scripts/lighthouse_audit.py`).
It sits in Frontend & Design, covering Performance optimization and Web performance. The licence is MIT.
When your agent uses it
- Tasks that involve Performance optimization
- Tasks that involve Web performance
Example prompts
- “/performance-profiling”
Requirements
- Python 3
- Pre-approved tools (allowed-tools): Read, Glob, Grep, Bash
Workflow steps
7 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit f0a1fa7. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
ReadGlobGrepBash
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 1 file in scripts/ (Python), which the agent can run.
Shell commands in SKILL.md call:
python
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 Profiling loads about 772 tokens when it runs. Until then it costs about 27 tokens; SKILL.md has 278 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: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Read, Glob, Grep, Bash
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); the scripts in this folder are not scanned.
SKILL.md
The full file from xenitV1/Antigravity-Workflows at commit f0a1fa7, republished under its MIT licence (© xenitV1). 278 words, ~772 tokens.
Download SKILL.mdSave it as
.claude/skills/performance-profiling/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.- name
- performance-profiling
- description
- Performance profiling principles. Measurement, analysis, and optimization techniques.
- allowed-tools
- Read, Glob, Grep, Bash
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 improvementProfiling 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 |
5. Common Bottlenecks
By Symptom
| Symptom | Likely Cause |
|---|---|
| Slow initial load | Large JS, render blocking |
| Slow interactions | Heavy event handlers |
| Jank during scroll | Layout thrashing |
| Growing memory | Leaks, retained refs |
6. Quick Win Priorities
| Priority | Action | Impact |
|---|---|---|
| 1 | Enable compression | High |
| 2 | Lazy load images | High |
| 3 | Code split routes | High |
| 4 | Cache static assets | Medium |
| 5 | Optimize images | Medium |
7. Anti-Patterns
| ❌ Don't | ✅ Do |
|---|---|
| Guess at problems | Profile first |
| Micro-optimize | Fix biggest issue |
| Optimize early | Optimize when needed |
| Ignore real users | Use RUM data |
Remember: The fastest code is code that doesn't run. Remove before optimizing.
© xenitV1, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 1 other file (scripts) in skills/performance-profiling of xenitV1/Antigravity-Workflows.
- SKILL.md
- scripts/lighthouse_audit.py
Open the folder on GitHubat commit f0a1fa7
Used in 7 other repositories
We found 16 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 7 other GitHub owners. This page covers the copy in xenitV1/Antigravity-Workflows, which our catalogue first saw on October 7, 2026.
- davila7/claude-code-templatescli-tool/components/skills/development/performance-profiling
- aiskillstore/marketplaceskills/sickn33/performance-profiling
- sickn33/agentic-awesome-skillsskills/performance-profilingplugins/agentic-awesome-skills/skills/performance-profiling+1 more
- agent-skills-hub/agent-skills-hubskills/performance-profiling
- lingxling/awesome-skills-cnantigravity-awesome-skills/skills/performance-profilingantigravity-awesome-skills/plugins/agentic-awesome-skills/skills/performance-profiling+1 more
- benjaminasterA/antigravity-awesome-skillsskills/performance-profiling
- henryalouf/ruflow.agents/skills/performance-profiling.agents/skills/antigravity-awesome-skills/skills/performance-profiling+4 more
Compare with similar skills
Performance Profiling 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 Profiling this skillxenitV1/Antigravity-Workflows | 130 | 7 repos | ~772 | Automated safety check: Notes | MIT | |
| React Best Practicesryokun6/ryos | 1.3k | — | ~2k | Automated safety check: Pass | MIT | |
| React Best Practicespoteto/noodle | 420 | — | ~1.4k | Automated safety check: Pass | MIT | |
| Vercel React Best Practicesgambitph/Stackable | 350 | — | ~2k | Automated safety check: Pass | MIT | |
| OptimizeMadAppGang/claude-code | 283 | — | ~4.7k | Automated safety check: Pass | MIT | |
| Electron DevTools Trace Analysiskeybase/client | 9.3k | — | ~809 | Automated safety check: Pass | BSD-3-Clause |
Similar skills
React Best Practices
poteto/noodle
React performance optimization guidelines. An agent skill from poteto/noodle.
Vercel React Best Practices
gambitph/Stackable
React performance optimization guidelines from Vercel Engineering.
Optimize
MadAppGang/claude-code
On-demand performance and optimization analysis. An agent skill from MadAppGang/claude-code.
Electron DevTools Trace Analysis
keybase/client
Analyzes Chrome or Electron DevTools Performance trace exports with Python scripts to find where render time actually goes, without opening DevTools.
Performance
midudev/100cosas.dev
Optimize web performance for faster loading and better user experience.
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Related
Categories
Questions about Performance Profiling
What does Performance Profiling do?
Performance profiling principles. An agent skill from xenitV1/Antigravity-Workflows. Performance Profiling is an agent skill from xenitV1/Antigravity-Workflows. Performance profiling principles.
When should I use Performance Profiling?
Performance Profiling fits situations like: tasks that involve Performance optimization; tasks that involve Web performance.
How do I install Performance Profiling in Claude Code?
Run `npx skills add xenitV1/Antigravity-Workflows --skill performance-profiling -a claude-code`. Or copy the skill folder (skills/performance-profiling in xenitV1/Antigravity-Workflows) into .claude/skills/performance-profiling in your project. Claude Code loads it when a task matches its description.
How do I install Performance Profiling in Codex?
Run `npx skills add xenitV1/Antigravity-Workflows --skill performance-profiling -a codex`. Or copy the skill folder (skills/performance-profiling in xenitV1/Antigravity-Workflows) into .agents/skills/performance-profiling in your project. Codex loads it when a task matches its description.
Can I use Performance Profiling 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 xenitV1/Antigravity-Workflows --skill performance-profiling -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-profiling, .gemini/skills/performance-profiling, .github/skills/performance-profiling and .opencode/skills/performance-profiling in your project.
What does Performance Profiling need to run?
Going by SKILL.md and its folder, Performance Profiling needs Python for the scripts in its folder and the command-line tools its instructions call (python). Our summary lists: Python 3. Its frontmatter pre-approves these tools: Read, Glob, Grep, Bash.
Does Performance Profiling 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 Profiling safe to install?
Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Performance Profiling use?
Performance Profiling is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Performance Profiling use?
About 772 tokens (SKILL.md is roughly 3.1k 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 Profiling?
Skills that share tags, products or a category with Performance Profiling: React Best Practices (ryokun6/ryos, 1.3k stars), React Best Practices (poteto/noodle, 420 stars), Vercel React Best Practices (gambitph/Stackable, 350 stars) and Optimize (MadAppGang/claude-code, 283 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Performance Profiling?
xenitV1 (a GitHub user) maintains it in xenitV1/Antigravity-Workflows, which has 130 GitHub stars. The repository holds 42 skills in this directory. The repository was last updated on January 14, 2026.
Source: xenitV1/Antigravity-Workflows on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.