perf-profiler

name	perf-profiler
user-invocable	false
description	Runtime performance analysis beyond Lighthouse — bundle size analysis, memory leak detection, HTTP load testing, resource optimization audit, and runtime CPU profiling. Use before launch or when investigating performance issues.
triggers	["performance check","bundle size","memory leak","load test","perf profile"]
category	backend
maturity	stable
tags	["load-testing","bundle-size","memory-leak","cpu-profiling","playwright"]

perf-profiler — Runtime Performance Analysis

Performance profiling beyond Lighthouse: bundle analysis, memory leak detection, load testing, resource analysis, and runtime CPU profiling.

Quick Start

perf-profiler bundle ./dist                    # Bundle size analysis
perf-profiler resources https://example.com    # Resource loading analysis
perf-profiler loadtest https://api.example.com --concurrency 20 --duration 30
perf-profiler memory https://app.example.com --iterations 10
perf-profiler runtime https://app.example.com --duration 10 --interaction scroll
perf-profiler review https://app.example.com --build-dir ./dist --full

Scripts

bundle.cjs — Bundle Size Analyzer

Analyzes JS/CSS files in build output. Reports per-file + gzipped sizes, detects heavy packages (moment→dayjs, lodash→lodash-es), parses source maps for package-level treemap.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/bundle.cjs <build-dir> [--source-maps]

Output: bundle-analysis.json

memory.cjs — Memory Leak Detector

Uses Playwright to navigate a page repeatedly, measuring heap size after each iteration. Linear regression detects consistent growth.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/memory.cjs <url> [--iterations 10] [--actions flow.json]

Custom actions JSON format:

[{"action":"click","selector":"button.open"},{"action":"wait","ms":500},{"action":"click","selector":"button.close"}]

loadtest.cjs — HTTP Load Tester

Zero-dependency concurrent load tester. Measures p50/p95/p99 latency, req/s, error rate.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/loadtest.cjs <url> \
  [--concurrency 10] [--duration 30] [--requests 1000] [--ramp] \
  [--method POST] [--body '{"key":"val"}'] [--header "Content-Type: application/json"]

resources.cjs — Resource Analysis

Monitors all network requests via CDP. Finds render-blocking resources, oversized images, unused CSS, uncompressed assets, third-party audit.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/resources.cjs <url> [--viewport mobile|desktop]

runtime.cjs — Runtime Performance Profiling

CDP-based CPU profiling, long task detection, layout thrashing, frame rate monitoring.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/runtime.cjs <url> [--duration 10] [--interaction scroll|click|idle]

review.cjs — Full Audit Orchestrator

Runs multiple tools and generates a combined scored report.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/review.cjs <url> \
  [--build-dir DIR] [--quick|--full] \
  [--load-concurrency N] [--load-duration S] [--memory-iterations N] \
  [--output-dir DIR] [--compare DIR]

report.cjs — Report Generator

Combines individual analysis JSON files into a scored Markdown + JSON report.

node ${CLAUDE_SKILLS_DIR:-$HOME/.claude-agent/.claude/skills}/perf-profiler/scripts/report.cjs [--input-dir DIR] [--output-dir DIR] [--compare DIR]

Dependencies

• playwright-core + a Chromium binary — see INSTALL.md for setup
• Node.js built-ins only otherwise (no other npm install needed)

Output

All scripts write JSON results to CWD. The report generator combines them into perf-report.json + perf-report.md with a 0-100 score.