react-performance-optimization

react-performance-optimization is an agent for Claude Code from davepoon/buildwithclaude. It costs 47 tokens per session (297 once invoked), scanned A, original, MIT.

A React performance analysis and optimization agent for finding slow rendering, large bundles, memory leaks, and poor Core Web Vitals. Core Web Vitals are browser measurements of loading speed, responsiveness, and visual stability.

In plain words
What is it for?
Use it to inspect React and browser performance, optimize components and bundles, add lazy loading and code splitting, investigate memory use, and analyze regressions.
Why use it?
It helps identify the specific causes of a slow React app and compare performance before and after changes.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agents-development-architecture plugin — 12 agents shipped together

Good fit Use it to inspect React and browser performance, optimize components and bundles, add lazy loading and code splitting, investigate memory use, and analyze regressions.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/davepoon/buildwithclaude/react-performance-optimization
About the project

davepoon/buildwithclaude is a discovery hub and plugin marketplace for Claude Code extensions, including agents, commands, hooks, skills, plugins, MCP servers, and marketplace collections. Developers use it to browse, search, and find installation instructions for tools that extend Claude-related workflows. Catalogue entries include agents, plugins, commands, and skills from this collection.

davepoon/buildwithclaude · 3,421 stars · on GitHub · buildwithclaude.com

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/davepoon/buildwithclaude

Made for: Claude Code.

Or install agents-development-architecture, the plugin that ships this one along with the rest of its 12 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for react-performance-optimization

README.md
[![agentmods](https://agentmods.dev/badge/agents/davepoon/buildwithclaude/react-performance-optimization.svg)](https://agentmods.dev/agents/davepoon/buildwithclaude/react-performance-optimization)
Your own site
<a href="https://agentmods.dev/agents/davepoon/buildwithclaude/react-performance-optimization"><img src="https://agentmods.dev/badge/agents/davepoon/buildwithclaude/react-performance-optimization.svg" alt="Measured on agentmods" height="20"></a>
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 297 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00047 $0.00297
Opus 5 $0.00023 $0.00148
Sonnet 5 $0.00009 $0.00059
Haiku 4.5 $0.00005 $0.00030

Measured 4d ago against content hash 56fe19815cd6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

react-performance-optimization scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/agents-development-architecture/agents/react-performance-optimization.md · 26 lines

What it actually says

You are a React Performance Optimization specialist focusing on identifying, analyzing, and resolving performance bottlenecks in React applications. Your expertise covers rendering optimization, bundle analysis, memory management, and Core Web Vitals.

When invoked:

Use this agent when dealing with React performance issues including slow loading applications, janky user interactions, large bundle sizes, memory leaks, poor Core Web Vitals scores, or performance regression analysis.

Process:

  1. Analyze current performance using React DevTools Profiler, Chrome DevTools, and Lighthouse
  2. Identify specific bottlenecks in rendering, bundle size, memory usage, or network performance
  3. Implement targeted optimizations using React.memo, useMemo, useCallback, code splitting, and lazy loading
  4. Measure performance improvements with before/after comparisons
  5. Provide specific, measurable solutions with concrete implementation examples

Provide:

  • Performance analysis report with metrics
  • Component memoization strategies with React.memo and useMemo
  • Code splitting implementation using React.lazy and Suspense
  • Bundle optimization techniques including tree shaking and dynamic imports
  • Memory leak identification and cleanup patterns
  • Core Web Vitals optimization recommendations
  • Before/after performance comparison data
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 26 lines · 47 tokens per session scan A 56fe19815cd6

Subscribe to this mod's changes

react-performance-optimization is an agent published in the GitHub repository davepoon/buildwithclaude (3,421 stars, last pushed today), licensed MIT. It adds 47 tokens to every session and 297 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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