react

react is a skill for Claude Code, Codex from MatrixAges/polywise. It costs 28 tokens per session (1,278 once invoked), scanned A, original, MIT.

A guide to building React user-interface components, including component structure, state handling, performance choices, and splitting large modules into smaller files.

In plain words
What is it for?
Use it when creating or changing React components, pages, interface logic, stateful views, or component-level performance behavior.
Why use it?
It gives developers consistent ways to organize React screens and avoid unnecessary updates or oversized components.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/matrixages/polywise/react
Any agent
npx skills add MatrixAges/polywise --skill react
Clone the repo
git clone --depth 1 https://github.com/MatrixAges/polywise

Made for: Claude Code, Codex.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/matrixages/polywise/react.svg)](https://agentmods.dev/skills/matrixages/polywise/react)
Your own site
<a href="https://agentmods.dev/skills/matrixages/polywise/react"><img src="https://agentmods.dev/badge/skills/matrixages/polywise/react.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,278 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00028 $0.01278
Opus 5 $0.00014 $0.00639
Sonnet 5 $0.00006 $0.00256
Haiku 4.5 $0.00003 $0.00128

Measured today against content hash e63c57c1a45d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react 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 today.

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.

.opencode/skills/react/SKILL.md · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React Development Guide

This skill provides a comprehensive guide for building React components in the project, focusing on performance, state management thresholds, and modular organization.

1. Component Architecture

1.1 Standard Component Pattern

Every component should follow the standard export pattern to ensure responsiveness (MobX) and performance (Memoization).

import { observer } from 'mobx-react-lite'

const Index = (props: IProps) => {
	const { data } = props

	return (
		<div className='flex flex-col p-4'>
			{/* Content */}
		</div>
	)
}

// ✅ Mandatory: For components needing state responsiveness or performance optimization, use $app.handle wrapper
export default new $app.handle(Index).by(observer).by($app.memo).get()

// ✅ Optional: For simple presentational components, directly use $app.memo
export default $app.memo(Index)

1.2 Module Splitting (Fractal Architecture)

Large modules must be split according to fractal patterns to maintain high maintainability and clear scope.

  • Local Components: Use components/ folder within the module directory. Component names should be concise (e.g., Item.tsx, Header.tsx).
  • Loop Extraction: Components rendered in loops (e.g., content inside .map()) must be extracted to separate component files to optimize diff rendering performance.
  • File Organization:
    module/
    ├── index.tsx                # Entry and layout
    ├── types.ts                 # Local type definitions
    ├── components/              # Local sub-components
    │   ├── List.tsx
    │   ├── Item.tsx             # Loop item component extraction
    │   └── index.ts             # Internal unified export
    ├── models/                  # (Optional) Local MobX models
    │   └── Local.ts
    └── styles/                  # (Optional) CSS Modules
        └── index.module.css
    

1.3 Props Management Pattern

To maintain component cleanliness and reference stability, follow these patterns for declaring and passing Props:

Read the full file on GitHub · 160 lines

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. today First seen · 160 lines · 28 tokens per session scan A e63c57c1a45d

Subscribe to this mod's changes

react is a skill published in the GitHub repository MatrixAges/polywise (659 stars, last pushed 2mo ago), licensed MIT. It adds 28 tokens to every session and 1,278 once invoked, about $0.0001 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 2026-09-04.

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