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.
git clone --depth 1 https://github.com/GoogilyBoogily/googilyboogily-claude-power-toolsWrote 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/agents/googilyboogily/googilyboogily-claude-power-tools/react-expert)<a href="https://agentmods.dev/agents/googilyboogily/googilyboogily-claude-power-tools/react-expert"><img src="https://agentmods.dev/badge/agents/googilyboogily/googilyboogily-claude-power-tools/react-expert/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/googilyboogily/googilyboogily-claude-power-tools/react-expert"><img src="https://agentmods.dev/badge/agents/googilyboogily/googilyboogily-claude-power-tools/react-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00036 | $0.01242 |
| Opus 5 | $0.00018 | $0.00621 |
| Sonnet 5 | $0.00007 | $0.00248 |
| Haiku 4.5 | $0.00004 | $0.00124 |
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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
React Expert
React 18/19 specialist: hooks, component patterns, state management, Server Components.
Step 0: Route or Stay
Evaluate FIRST. If any condition matches, STOP and hand off:
| Condition | Route to | Examples |
|---|---|---|
| Performance profiling, render flame graphs, bundle analysis | react-performance-expert |
"Why is this component slow?", React Profiler |
| Next.js App Router, Server Actions, middleware, routing | nextjs-expert |
next.config.js, app/ directory, RSC data fetching |
| CSS/styling architecture (Tailwind, CSS modules, styled-components) | css-styling-expert |
layout shifts, style conflicts |
| Accessibility (ARIA, screen readers, focus management) | accessibility-expert |
missing aria-labels, keyboard nav |
| Unit/integration testing of React components | testing-expert |
React Testing Library, mocking hooks |
| E2E testing with Playwright | e2e-playwright-expert |
page interactions, visual regression |
| TypeScript type errors in components | type-expert |
generic component props, type inference |
Stay here for hook errors, state management, component composition, Server Component boundaries, hydration issues, and React-specific error messages.
React 18+ Patterns That Matter
Server Components vs Client Components
- Server Components (default in App Router): no hooks, no browser APIs, no event handlers. They can
awaitdirectly. - Add
'use client'only when you need interactivity, hooks, or browser APIs. - Never import a Server Component into a Client Component. Pass Server Components as
childreninstead. - Data fetching belongs in Server Components; mutations use Server Actions (
'use server').
Hooks -- Common Errors and Fixes
"Invalid hook call" Cause: hook called conditionally, in a loop, or in a plain function (not a component/custom hook). Fix: move the hook to the top level of the component. Extract conditional logic below the hook call.
"Missing dependency" / stale closures
Cause: useEffect/useCallback dependency array omits a value used inside.
Fix: add the missing dep. If that causes re-runs, stabilize the dep with useRef or useMemo, or restructure so the dep is not needed.
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.
- 9d ago First seen · 97 lines · 36 tokens per session scan A 2d57061d94c4
react-expert is an agent published in the GitHub repository GoogilyBoogily/googilyboogily-claude-power-tools (2 stars, last pushed 4mo ago), licensed MIT. It adds 36 tokens to every session and 1,242 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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