Agent skill

Perf Profiling

by 312362115 in 312362115/claude

前后端性能分析技能:定位瓶颈、跑 benchmark、对比优化前后效果. An agent skill from 312362115/claude.

MITAuto-check passedFrontend & Design

Install Perf Profiling

skills CLI
$ npx skills add 312362115/claude --skill perf-profiling -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install 312362115/claude perf-profiling --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/312362115/claude.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/perf-profiling .claude/skills/perf-profiling && rm -rf skills-src

Use ~/.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/

Facts

Skill name
perf-profiling
GitHub stars
107
Token cost
~1.1k tokens
SKILL.md length
177 words
Files
1
Skills in repo
20
Repo updated
First seen
Licence
MIT

At a glance

前后端性能分析技能:定位瓶颈、跑 benchmark、对比优化前后效果. An agent skill from 312362115/claude.

  • Tasks that involve Web performance
  • SKILL.md covers 第一步:明确分析目标, 前端性能分析, 后端性能分析 and 第四步:优化与对比, plus 2 more sections
  • Calls node, npx and python

What it does

Perf Profiling is an agent skill from 312362115/claude. 前后端性能分析技能:定位瓶颈、跑 benchmark、对比优化前后效果。 前端覆盖 Core Web Vitals(LCP/FID/CLS)、Lighthouse 审计、Bundle 分析。 后端覆盖 API 响应时间、数据库查询性能、内存/CPU profiling。 核心原则:基于数据定位瓶颈,不做无依据的"优化"。 触发词:性能优化、太慢了、性能分析、LCP、首屏、响应时间慢、profiling、benchmark。 触发场景:性能相关需求验收、用户反馈慢、性能指标超标、重构后性能回归验证。

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Frontend & Design, covering Web performance. The licence is MIT.

When your agent uses it

  • Tasks that involve Web performance

Example prompts

  • “/perf-profiling”

Requirements

  • Python 3
  • Node.js

What it can do on your machine

Read from SKILL.md and the folder at commit 2d4fa49. 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

    Shell commands in SKILL.md call:

    • node
    • npx
    • python
    • curl
    • pip

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md. Its commands use npx, curl and pip, which can reach the network depending on how they are called.

    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

Perf Profiling loads about 1.1k tokens when it runs. Until then it costs about 67 tokens; SKILL.md has 177 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~67
When it runs · the whole SKILL.md, loaded when a task matches
~1.1k

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

The full file from 312362115/claude at commit 2d4fa49, republished under its MIT licence (© 312362115). 177 words, ~1,104 tokens.

Download SKILL.mdSave it as .claude/skills/perf-profiling/SKILL.md (or your agent's skills folder).
name
perf-profiling
description
前后端性能分析技能:定位瓶颈、跑 benchmark、对比优化前后效果。 前端覆盖 Core Web Vitals(LCP/FID/CLS)、Lighthouse 审计、Bundle 分析。 后端覆盖 API 响应时间、数据库查询性能、内存/CPU profiling。 核心原则:基于数据定位瓶颈,不做无依据的"优化"。 触发词:性能优化、太慢了、性能分析、LCP、首屏、响应时间慢、profiling、benchmark。 触发场景:性能相关需求验收、用户反馈慢、性能指标超标、重构后性能回归验证。
version
1.0.0
last_updated
2026-04-08
repository
https://github.com/312362115/claude

性能分析(Perf Profiling)

优化的前提是度量。不知道慢在哪,就不知道该优化哪。 每次优化都要有"前"和"后"的数据对比,否则不算优化。


第一步:明确分析目标

性能问题
  │
  ├─ 前端性能?(页面加载慢、交互卡顿、首屏慢)
  │   └─ 前端分析流程
  │
  ├─ 后端性能?(API 响应慢、数据库查询慢、CPU/内存高)
  │   └─ 后端分析流程
  │
  └─ 不确定?
      └─ 先用浏览器 DevTools Network 面板判断瓶颈在前端还是后端

用 AskUserQuestion 确认:

  • 具体症状:哪里慢?慢到什么程度?(要数据,不要"感觉")
  • 性能基线:当前是多少?目标是多少?
  • 复现条件:特定页面?特定数据量?特定并发?

前端性能分析

2.1 Core Web Vitals 度量
指标含义达标需改进差
LCP最大内容绘制≤2.5s≤4s>4s
INP交互到下一次绘制≤200ms≤500ms>500ms
CLS累计布局偏移≤0.1≤0.25>0.25

度量工具:

bash
# Lighthouse CLI(如果可用)
npx lighthouse <url> --output=json --output-path=./lighthouse-report.json

# 或用 Playwright 采集性能数据
# 通过 MCP playwright 工具访问页面并执行 performance API
2.2 Bundle 分析
bash
# Webpack
npx webpack-bundle-analyzer stats.json

# Vite
npx vite-bundle-visualizer

# Next.js
ANALYZE=true next build

关注点:

  • 总 bundle 大小(gzip 后)
  • 最大的几个依赖占比
  • 有没有重复打包的依赖
  • 是否做了 code splitting
2.3 前端常见瓶颈与优化方向
瓶颈诊断方式优化方向
首屏大图/大资源阻塞 LCPLighthouse / Network 瀑布图懒加载、压缩、CDN、preload 关键资源
JS Bundle 过大Bundle 分析Code splitting、tree shaking、动态导入
未优化图片Lighthouse 图片审计WebP/AVIF、响应式图片、压缩
布局抖动导致 CLSLighthouse CLS 审计固定尺寸占位、字体预加载
大量 DOM 操作Performance timeline虚拟列表、减少重排、requestAnimationFrame
第三方脚本阻塞Network + Coverage延迟加载、异步加载、移除不必要的三方脚本

后端性能分析

3.1 API 响应时间度量
bash
# 简单测量(单次)
time curl -s -o /dev/null -w "%{time_total}" <api-url>

# 并发测试(如 wrk 可用)
wrk -t4 -c100 -d30s <api-url>

# 或用 Node.js 脚本测量
node -e "
const start = Date.now();
fetch('<api-url>').then(() => console.log(Date.now() - start + 'ms'));
"

记录关键指标:

  • p50 / p95 / p99 响应时间
  • 吞吐量(req/s)
  • 错误率
3.2 数据库查询分析
sql
-- MySQL/PostgreSQL 查询分析
EXPLAIN ANALYZE <your-query>;
javascript
// Node.js ORM 慢查询日志
// Prisma: 在 PrismaClient 初始化时开启
const prisma = new PrismaClient({ log: ['query', 'warn', 'error'] });

// Sequelize: 开启 benchmark
const sequelize = new Sequelize({ benchmark: true, logging: console.log });

关注点:

  • 全表扫描(缺索引)
  • N+1 查询
  • 未使用的索引
  • 慢查询(>100ms)
3.3 Node.js / Python Profiling

Node.js:

bash
# CPU profiling
node --prof app.js
node --prof-process isolate-xxx.log > processed.txt

# 内存快照
node --inspect app.js
# 然后在 Chrome DevTools 中 Take Heap Snapshot

Python:

bash
# cProfile
python -m cProfile -s cumtime app.py

# memory_profiler
pip install memory_profiler
python -m memory_profiler app.py
3.4 后端常见瓶颈与优化方向
瓶颈诊断方式优化方向
数据库查询慢EXPLAIN ANALYZE加索引、优化查询、减少 N+1
序列化/反序列化开销profiling减少响应字段、分页、缓存
外部 API 调用阻塞timing 日志并行调用、缓存、超时控制
内存泄漏内存快照对比排查未释放的引用、闭包
CPU 密集计算CPU profilingWorker 线程、缓存计算结果
连接池耗尽连接池监控调整池大小、检查连接泄漏

第四步:优化与对比

4.1 优化前记录基线

在做任何改动之前,必须记录当前性能数据:

markdown
## 性能基线(优化前)

| 指标 | 值 | 测量条件 |
|------|-----|---------|
| LCP | 3.8s | 首页,Chrome,4G 模拟 |
| API /users 响应 | p95: 450ms | 100 并发,30s |
| 数据库查询 | 320ms | users 表 10 万行 |
4.2 优化后对比

每次优化后,用相同条件重新测量,对比前后:

markdown
## 优化效果对比

| 指标 | 优化前 | 优化后 | 改善 |
|------|--------|--------|------|
| LCP | 3.8s | 1.9s | -50% ✅ |
| API /users p95 | 450ms | 120ms | -73% ✅ |
| Bundle 大小 | 2.1MB | 890KB | -58% ✅ |
4.3 输出性能报告

完整性能分析后,输出报告到 docs/specs/ 或直接在对话中给出:

markdown
# 性能分析报告:<模块/页面>

## 问题描述
用户反馈/指标异常的具体描述

## 分析结论
瓶颈在哪,为什么慢

## 优化措施
| # | 措施 | 预期效果 | 实际效果 |
|---|------|---------|---------|

## 性能对比
基线 vs 优化后

## 后续建议
还可以进一步优化的方向

分析准则

  • 数据驱动:不凭直觉优化。先度量,找到瓶颈,再优化,再度量
  • 优先级:先优化影响最大的瓶颈(80/20 法则)
  • 工具按项目选:不强制某个工具,项目里有什么用什么,缺什么建议安装什么
  • 不过度优化:达到目标就停。从 3s 优化到 2s 和从 2s 优化到 1.5s 的成本完全不同
  • 回归保护:性能优化不能破坏功能。优化后必须跑测试确认功能正常

与其他 skill 的关系

task-execute 执行中发现性能问题 → perf-profiling(分析定位)
refactoring 重构后 → perf-profiling(回归验证,确认性能没退化)
release 发版前 → perf-profiling(性能相关需求的验收)

© 312362115, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/perf-profiling of 312362115/claude.

Open the folder on GitHubat commit 2d4fa49

Compare with similar skills

Perf 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.

Perf Profiling compared with similar skills
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Perf Profiling this skill312362115/claude107—~1.1kAutomated safety check: PassMIT
React Doctormakeplane/plane61k12 repos~657Automated safety check: PassAGPL-3.0
Fixing Motion Performanceibelick/ui-skills9.5k5 repos~1.4kAutomated safety check: PassMIT
GSAP Performance Tuninggreensock/gsap-skills16k4 repos~1kAutomated safety check: PassMIT
React Frontend Development Guidelinesdiet103/claude-code-infrastructure-showcase10k2 repos~2.9kAutomated safety check: PassMIT
Web Quality Auditaddyosmani/web-quality-skills2.9k—~2.6kAutomated safety check: PassMIT

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Questions about Perf Profiling

What does Perf Profiling do?

前后端性能分析技能:定位瓶颈、跑 benchmark、对比优化前后效果. An agent skill from 312362115/claude. Perf Profiling is an agent skill from 312362115/claude.

When should I use Perf Profiling?

Perf Profiling fits situations like: tasks that involve Web performance.

How do I install Perf Profiling in Claude Code?

Run `npx skills add 312362115/claude --skill perf-profiling -a claude-code`. Or copy the skill folder (skills/perf-profiling in 312362115/claude) into .claude/skills/perf-profiling in your project. Claude Code loads it when a task matches its description.

How do I install Perf Profiling in Codex?

Run `npx skills add 312362115/claude --skill perf-profiling -a codex`. Or copy the skill folder (skills/perf-profiling in 312362115/claude) into .agents/skills/perf-profiling in your project. Codex loads it when a task matches its description.

Can I use Perf 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 312362115/claude --skill perf-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/perf-profiling, .gemini/skills/perf-profiling, .github/skills/perf-profiling and .opencode/skills/perf-profiling in your project.

What does Perf Profiling need to run?

Going by SKILL.md and its folder, Perf Profiling needs the command-line tools its instructions call (node, npx, python, curl and pip). Our summary lists: Python 3; Node.js.

Does Perf Profiling access the network?

SKILL.md contains no URLs. Its commands use npx, curl and pip, which can reach the network depending on how they are called. This is read from the text; nothing was executed.

Is Perf Profiling 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 Perf Profiling use?

Perf 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 Perf Profiling use?

About 1.1k tokens (SKILL.md is roughly 4.4k 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 Perf Profiling?

Skills that share tags, products or a category with Perf Profiling: React Doctor (makeplane/plane, 61k stars), Fixing Motion Performance (ibelick/ui-skills, 9.5k 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 Perf Profiling?

312362115 (a GitHub user) maintains it in 312362115/claude, which has 107 GitHub stars. The repository holds 20 skills in this directory. The repository was last updated on May 14, 2026.

Source: 312362115/claude on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.