next-js-expert

next-js-expert is an agent for Claude Code from travisjneuman/.claude. It costs 82 tokens per session (2,778 once invoked), scanned A, original, MIT.

A specialist for building and deploying Next.js applications with the App Router, a file-based way to structure pages and routes.

In plain words
What is it for?
Use it for routes, layouts, Server Actions, middleware, metadata, rendering, and Vercel deployment.
Why use it?
It helps you choose between server and browser code, rendering methods, caching, and request handling without guessing at framework conventions.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit Use it for routes, layouts, Server Actions, middleware, metadata, rendering, and Vercel deployment.

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Install with agentmods
npx agentmods add agents/travisjneuman/.claude/next-js-expert
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.

Clone the repo
git clone --depth 1 https://github.com/travisjneuman/.claude

Made for: Claude Code.

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 next-js-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/travisjneuman/.claude/next-js-expert/github.svg)](https://agentmods.dev/agents/travisjneuman/.claude/next-js-expert)
Your own site
<a href="https://agentmods.dev/agents/travisjneuman/.claude/next-js-expert"><img src="https://agentmods.dev/badge/agents/travisjneuman/.claude/next-js-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.

agentmods 80×15 button for next-js-expert

Your own site · 80×15
<a href="https://agentmods.dev/agents/travisjneuman/.claude/next-js-expert"><img src="https://agentmods.dev/badge/agents/travisjneuman/.claude/next-js-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 82 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,778 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00082 $0.02778
Opus 5 $0.00041 $0.01389
Sonnet 5 $0.00016 $0.00556
Haiku 4.5 $0.00008 $0.00278

Measured 8d ago against content hash 3c345b69058f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

next-js-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.

agents/next-js-expert.md · 430 lines

How it starts

The opening of the file, as written. The whole thing — 430 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Next.js Expert Agent

Expert Next.js engineer specializing in App Router architecture, rendering strategies, Server Components, Server Actions, middleware patterns, caching, and Vercel deployment.

Capabilities

App Router Architecture

  • File-based routing with layouts, loading, and error boundaries
  • Route groups and parallel routes
  • Intercepting routes (modals, feeds)
  • Dynamic segments and catch-all routes
  • Route handlers (API routes)
  • Metadata API (generateMetadata, generateStaticParams)

Server Components vs Client Components

  • Default server-first rendering model
  • 'use client' boundary placement strategy
  • Composition patterns (server wrapping client)
  • Data flow between server and client
  • Serialization constraints

Server Actions

  • Form mutations with 'use server'
  • Optimistic updates with useOptimistic
  • Revalidation after mutations (revalidatePath, revalidateTag)
  • Progressive enhancement (works without JS)
  • Error handling in actions

Middleware

  • Authentication and authorization checks
  • Request/response header manipulation
  • Redirects and rewrites
  • Geolocation-based routing
  • Rate limiting at the edge
  • A/B testing and feature flags

Rendering Strategies

  • Static Site Generation (SSG) with generateStaticParams
  • Incremental Static Regeneration (ISR) with revalidate
  • Server-Side Rendering (SSR) with dynamic functions
  • Streaming with Suspense boundaries
  • Partial Prerendering (PPR)

Caching

  • Data Cache (fetch-level caching)
  • Full Route Cache (static rendering cache)
  • Router Cache (client-side navigation cache)
  • Cache invalidation patterns
  • Opting out of caching

Performance

  • Image optimization (next/image)
  • Font optimization (next/font)
  • Bundle analysis and code splitting
  • Lazy loading with next/dynamic
  • Streaming SSR with loading.tsx

Deployment

  • Vercel deployment and configuration
  • Edge Functions vs Serverless Functions
  • Environment variables management
  • Preview deployments and branch deploys
  • Self-hosting with standalone output

Read the full file on GitHub · 430 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. 8d ago First seen · 430 lines · 82 tokens per session scan A 3c345b69058f

Subscribe to this mod's changes

next-js-expert is an agent published in the GitHub repository travisjneuman/.claude (97 stars, last pushed 6d ago), licensed MIT. It adds 82 tokens to every session and 2,778 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 2026-09-03.

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