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    Perf Budget Auditor

    Perf Budget Auditor

    by JustHandled Labs

    Audit your frontend build against a performance budget and catch size regressions before you ship. Flags total bundle over budget, initial bundle over budget, individual chunks over a threshold, oversized image assets, source maps shipped to production, and large unminified JavaScript. Reads a webpack or Vite-style stats.json plus a perf-budget.json you control.

    Updated Jun 2026
    Security scanned
    Cursor

    $12

    · or 60 credits

    30-day refund guarantee

    Secure checkout via Stripe

    Included in download

    • Detect oversized JavaScript bundles and assets during CI/CD or local builds
    • Identify leaked source maps and unminified code in production artifacts
    • terminal, file_read automation included
    • Ready for Cursor
    • Instant install

    Sample input

    Audit my dist folder against our performance budget and let me know if the build is safe to deploy.

    Sample output

    Perf Budget Audit Results

    • Severity: HIGH | Rule: INITIAL_JS_BUDGET
    • File: dist/assets/index-D4f2a.js (450KB)
    • Message: Exceeds initial budget of 200KB.
    • Remediation: Use dynamic imports to code-split non-critical modules or check for duplicate dependencies.

    About This Skill

    What it does

    Perf Budget Auditor is a specialized developer tool designed to automatically detect frontend performance regressions before they reach production. It scans build artifacts, manifests (stats.json), and asset folders to identify oversized bundles, unoptimized images, leaked source maps, and unminified JavaScript.

    Why use this skill

    Manually checking file sizes after every build is tedious and error-prone. This skill automates the audit process by comparing your build output against defined performance budgets (perf-budget.json). It provides actionable remediation guidance rather than just raw numbers, helping developers pinpoint exactly which chunks or assets are bloating the application.

    Supported tools

    • Standard web build folders (dist, build, out)
    • Webpack/Rollup/Vite manifest files (stats.json)
    • Custom performance budget configurations
    • Common frontend assets (JS, CSS, WASM, Images)

    Output Expected

    You will receive a structured report detailing the inspected scope, specific rule violations, severity levels, and precise file paths. Each finding includes "evidence" (e.g., actual size vs. budget) and clear remediation steps to fix the bloat.

    Use Cases

    • Detect oversized JavaScript bundles and assets during CI/CD or local builds
    • Identify leaked source maps and unminified code in production artifacts
    • Enforce performance budgets using custom thresholds or stats.json manifests
    • Get actionable remediation steps for specific bundle size regressions

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    Security Scanned

    Passed automated security review

    Permissions

    Terminal / Shell
    Read Files

    Allowed Hosts

    www.agensi.io

    File Scopes

    perf-budget-auditor/**
    **/stats.json
    **/perf-budget.json
    **/dist/**/*
    **/build/**/*
    **/*.bundle.js

    Read-only. Parses stats and budget JSON with the standard library and inspects output file sizes. Ships default thresholds, overridable via perf-budget.json. It does not execute the build or read environment variables.

    Tags

    web-perf
    frontend
    build-tools
    performance
    javascript

    Works with any agent that can read a build directory and run a local Python script (Claude Code, Cursor, Codex CLI, and other SKILL.md-compatible agents). Standard library only, no install step. It reads build manifests and output file sizes; it does not run the bundler. Read-only.

    Creator

    JustHandled Labs

    JustHandled Labs creates focused agent skills and workflow packs for Claude, Codex, Cursor, and AI-assisted builders. Each tool is designed around a real repeatable task: cleaner commits, better PRs, stronger handoffs, safer repo hygiene, clearer documentation, and less copy-paste chaos. The goal is not generic AI productivity. The goal is specific workflows that are easier to run, review, and repeat. Maintained by H.J. Westerfield, with a background in communications, editing, project coordination, customer support, and practical AI systems. JustHandled Labs builds tools for people who want useful automation without theatrical complexity.

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