claude-skills is a collection of specialized skills that extends Claude Code for full-stack development. Developers use it for programming languages, frameworks, infrastructure, APIs, testing, DevOps, security, data and machine learning, platform tasks, and project workflows.
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.
npx skills add Jeffallan/claude-skills --skill react-expertgit clone --depth 1 https://github.com/Jeffallan/claude-skillsWrote 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.
[](https://agentmods.dev/skills/jeffallan/claude-skills/react-expert)<a href="https://agentmods.dev/skills/jeffallan/claude-skills/react-expert"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/react-expert.svg" alt="Measured on agentmods" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00079 | $0.01221 |
| Opus 5 | $0.00039 | $0.00611 |
| Sonnet 5 | $0.00016 | $0.00244 |
| Haiku 4.5 | $0.00008 | $0.00122 |
Grade A, and why
react-expert 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 8d 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.
Copies of this mod
6 near-identical copies found in the catalogue:
- react-expert — 100% identical, 0 lines differ
- react-expert — 95% identical, 2 lines differ
- react-expert — 95% identical, 2 lines differ
- react-expert — 86% identical, 113 lines differ
- react-expert — 83% identical, 83 lines differ
- react-expert — 83% identical, 83 lines differ
How it starts
The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React Expert
Senior React specialist with deep expertise in React 19, Server Components, and production-grade application architecture.
When to Use This Skill
- Building new React components or features
- Implementing state management (local, Context, Redux, Zustand)
- Optimizing React performance
- Setting up React project architecture
- Working with React 19 Server Components
- Implementing forms with React 19 actions
- Data fetching patterns with TanStack Query or
use()
Core Workflow
- Analyze requirements - Identify component hierarchy, state needs, data flow
- Choose patterns - Select appropriate state management, data fetching approach
- Implement - Write TypeScript components with proper types
- Validate - Run
tsc --noEmit; if it fails, review reported errors, fix all type issues, and re-run until clean before proceeding - Optimize - Apply memoization where needed, ensure accessibility; if new type errors are introduced, return to step 4
- Test - Write tests with React Testing Library; if any assertions fail, debug and fix before submitting
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Server Components | references/server-components.md |
RSC patterns, Next.js App Router |
| React 19 | references/react-19-features.md |
use() hook, useActionState, forms |
| State Management | references/state-management.md |
Context, Zustand, Redux, TanStack |
| Hooks | references/hooks-patterns.md |
Custom hooks, useEffect, useCallback |
| Performance | references/performance.md |
memo, lazy, virtualization |
| Testing | references/testing-react.md |
Testing Library, mocking |
| Class Migration | references/migration-class-to-modern.md |
Converting class components to hooks/RSC |
Key Patterns
Server Component (Next.js App Router)
// app/users/page.tsx — Server Component, no "use client"
import { db } from '@/lib/db';
interface User {
id: string;
name: string;
}
export default async function UsersPage() {
const users: User[] = await db.user.findMany();
return (
<ul>
{users.map((user) => (
<li key={user.id}>{user.name}</li>
))}
</ul>
);
}
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 8d ago First seen · 152 lines · 79 tokens per session scan A 542b344c6b4c
react-expert is a skill published in the GitHub repository Jeffallan/claude-skills (11,347 stars, last pushed 1mo ago), licensed MIT. It adds 79 tokens to every session and 1,221 once invoked, about $0.0004 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 2026-08-30.
Other skills, from other repositories
react-arch
Create the complete frontend architecture for a new entity in the React application. Generates TypeScript types, service class, context provider, custom hook, and registers the provider in main.tsx. Use this skill when the user asks to create a new entity, feature module, or domain area in the frontend.
add-react-i18n
Add react-i18next internationalization to a React NPM library package. Creates isolated i18n instance, translation files, modifies provider and components. Use when the user wants to add multi-language support to a React component library.
react-modal
Create modal dialogs in the frontend using a custom Modal component built on top of Radix UI Dialog. Use this skill whenever the user asks to create, add, or modify a modal, dialog, popup, or confirmation prompt in the React application.
react-alert
Display user-facing alerts, notifications, and feedback messages using toast notifications from the sonner library. Use this skill whenever the user asks to show an alert, notification, success message, error message, warning, or any kind of user feedback popup.
react-architecture
Create the complete frontend architecture for a new entity in the React application. Generates TypeScript types, service class, context provider, custom hook, and registers the provider in main.tsx. Use this skill when the user asks to create a new entity, feature module, or domain area in the frontend.
extract-source-sample
Given the path to a finished content-goose ad-run folder, extract everything that defines that ad — recipe shot list, VO script, characters, voices, world, atom-skills, master mp4 — and emit a source-sample.json in the exact shape the upload-ad-sample skill writes to the Goose Ads library. Also links every character…