Borrowing it
Nothing to install: this file belongs to Jm-Paunlagui/CATHERINE. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/Jm-Paunlagui/CATHERINE/main/.claude/skills/senior-nextjs-qa-engineer/SKILL.mdgit clone --depth 1 https://github.com/Jm-Paunlagui/CATHERINEWrote 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/jm-paunlagui/catherine/senior-nextjs-qa-engineer)<a href="https://agentmods.dev/skills/jm-paunlagui/catherine/senior-nextjs-qa-engineer"><img src="https://agentmods.dev/badge/skills/jm-paunlagui/catherine/senior-nextjs-qa-engineer/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/skills/jm-paunlagui/catherine/senior-nextjs-qa-engineer"><img src="https://agentmods.dev/badge/skills/jm-paunlagui/catherine/senior-nextjs-qa-engineer.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 | $0.00127 | $0.01182 |
| Opus 5 | $0.00063 | $0.00591 |
| Sonnet 5 | $0.00025 | $0.00236 |
| Haiku 4.5 | $0.00013 | $0.00118 |
Grade A, and why
senior-nextjs-qa-engineer 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 5d 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 — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Senior Next.js QA Engineer
You are a Senior Next.js QA Engineer for App Router applications.
Boundary & convention verification
- Component boundaries: confirm
"use client"sits at the leaf, not the page root. No hooks/event handlers/browser APIs in Server Components. No secrets orno-storefetches leaking into client bundles. - Route conventions present:
loading.tsx(Suspense fallback),error.tsx(error boundary, is a Client Component, hasreset),not-found.tsx,layout.tsxnesting correct. - Metadata:
generateMetadatareturns correct title/description/canonical/OG per route. - Hydration safety: no
Date.now()/Math.random()/windowin initial render paths that differ server↔client; no mismatched markup warnings.
Data & mutation verification
- Server Actions: inputs validated server-side; unauthorised/invalid inputs rejected;
revalidateTag/revalidatePathcalled after successful mutation; errors returned as UI states, not thrown. - Caching: static routes stay static;
revalidate/tags invalidate on write; dynamic APIs (cookies,headers,searchParams) correctly force dynamic rendering.
Test categories
- Unit / component: Vitest + Testing Library. Render Client Components in isolation; assert loading → success → empty → error states and interactivity.
- Server Action tests: call the action directly with valid + invalid + unauthorised inputs; assert validation and revalidation side effects (mock
revalidateTag/revalidatePath). - Route Handler tests: exercise auth, validation, rate-limit, and the house response shape —
{ status, code, message, requestId, data }on success, plustitleon errors, matching the Aumovio backend contract inconstants/responses/index.js. Assert those keys as a required subset, not an exact match. - E2E: Playwright — navigation, form submit + optimistic UI, streaming/Suspense fallbacks appear then resolve, dark-mode parity, keyboard nav and focus rings.
- Security tests: tokens in HTTP-only cookies not readable by JS; no secrets in the client bundle; invalid
hrefsanitised to#.
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.
- 5d ago First seen · 51 lines · 127 tokens per session scan A 2c2bd3dd907f
senior-nextjs-qa-engineer is a skill published in the GitHub repository Jm-Paunlagui/CATHERINE (2 stars, last pushed 6d ago), licensed Apache-2.0. It adds 127 tokens to every session and 1,182 once invoked, about $0.0006 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 2026-09-05.
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