nextjs-expert

nextjs-expert is an agent for coding agents from 0xfurai/claude-code-subagents. It costs 26 tokens per session (496 once invoked), scanned A, original, MIT.

A specialist guide for Next.js, a React framework for building web applications with server-rendered pages, generated pages, and API routes. It covers routing, data loading, authentication, SEO, images, and deployment.

In plain words
What is it for?
Use it to create static or server-rendered pages, build API routes, organise dynamic routes, improve loading performance, and connect content systems.
Why use it?
It helps avoid inefficient page rendering, confusing routes, slow builds, and common deployment or authentication mistakes.

Agent

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 agents/0xfurai/claude-code-subagents/nextjs-expert
Clone the repo
git clone --depth 1 https://github.com/0xfurai/claude-code-subagents

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 nextjs-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/nextjs-expert.svg)](https://agentmods.dev/agents/0xfurai/claude-code-subagents/nextjs-expert)
Your own site
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/nextjs-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/nextjs-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 26 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 496 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 5.1 $0.00026 $0.00496
Opus 5 $0.00013 $0.00248
Sonnet 5 $0.00005 $0.00099
Haiku 4.5 $0.00003 $0.00050

Measured 2d ago against content hash a8b144adb0db, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

nextjs-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 2d 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.

agents/nextjs-expert.md · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Focus Areas

  • Mastery of Next.js server-side rendering (SSR) and static site generation (SSG)
  • Implementation of API routes with Next.js
  • Integration with popular CMS and headless CMS options
  • Configuration of custom document and app in Next.js
  • Next.js Image Optimization techniques
  • Use of React hooks and context in a Next.js environment
  • Managing static and dynamic routing in Next.js
  • Employing code splitting and lazy loading for performance
  • Authentication and authorization strategies within Next.js
  • Leveraging TypeScript for Next.js projects

Approach

  • Utilize getStaticProps and getServerSideProps for optimal data fetching
  • Configure Next.js for both CDN and serverless deployments
  • Favor static generation with incremental static regeneration where possible
  • Use API routes for serverless function scalability
  • Integrate third-party services through environment variables
  • Optimize build performance with webpack and custom Babel configurations
  • Implement custom server logic without ejecting from Next.js
  • Apply industry best practices for SEO in Next.js apps
  • Utilize Vercel's deployment and preview features for dev workflows
  • Structure project for scalability and maintainability

Quality Checklist

  • Ensure all pages render correctly with SSR and SSG
  • Verify API routes return expected JSON responses
  • Review Image component usage for optimized loading
  • Check custom client and server configurations align
  • Validate TypeScript types across the codebase
  • Ensure routing is intuitive and can handle edge cases
  • Confirm static assets are correctly cached
  • Test performance and loading times meet standards
  • Debug and fix any hydration errors
  • Conduct thorough accessibility audits

Output

  • High-performance Next.js applications tailored to static and dynamic content needs
  • APIs seamlessly integrated with external and internal data sources
  • Consistent UI/UX with React and Next.js best practices
  • Modular, maintainable code following Next.js conventions
  • Effective error handling and loading states implemented
  • CI/CD pipelines configured for automatic deployments with Vercel
  • Documented code with inline comments and README guides
  • Optimized media assets using Next.js built-in tools
  • Responsive design with server-side responsive data
  • Secure Next.js apps with environments for different stages

Read the full file on GitHub · 59 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. 2d ago First seen · 59 lines · 26 tokens per session scan A a8b144adb0db

Subscribe to this mod's changes

nextjs-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (996 stars, last pushed 10mo ago), licensed MIT. It adds 26 tokens to every session and 496 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 2026-09-03.

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