nextjs-developer

nextjs-developer is a skill for Claude Code from Jeffallan/claude-skills. It costs 115 tokens per session (1,295 once invoked), scanned A, original, MIT.

A guide for building Next.js 14+ web applications with file-based routing, server-rendered components, server actions, data fetching, and deployment support.

In plain words
What is it for?
Use it to create routes and layouts, handle loading and error states, fetch and cache data, process server-side form changes, generate SEO metadata, and prepare apps for Vercel.
Why use it?
It helps organize full-stack Next.js applications and check builds, environment settings, SEO, and page performance.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is import { createProduct } from '../actions'.

Part of the fullstack-dev-skills plugin — 57 skills shipped together

Good fit Use it to create routes and layouts, handle loading and error states, fetch and cache data, process server-side form changes, generate SEO metadata, and prepare apps for Vercel.

Compare 6 skills from other repositories ↓
About the project

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.

Jeffallan/claude-skills · 11,347 stars · on GitHub

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/Jeffallan/claude-skills
agentmods
npx agentmods add skills/jeffallan/claude-skills/nextjs-developer

Made for: Claude Code.

Or install fullstack-dev-skills, the plugin that ships this one along with the rest of its 57 skills.

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-developer

README.md
[![agentmods](https://agentmods.dev/badge/skills/jeffallan/claude-skills/nextjs-developer.svg)](https://agentmods.dev/skills/jeffallan/claude-skills/nextjs-developer)
Your own site
<a href="https://agentmods.dev/skills/jeffallan/claude-skills/nextjs-developer"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/nextjs-developer.svg" alt="Measured on agentmods" height="20"></a>
Per session 115 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,295 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. Third-party audits
  • Socket pass 29 Apr 2026
  • Snyk pass 29 Apr 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Data Exfiltration · line 65
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
How audits are shown
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 $0.00115 $0.01295
Opus 5 $0.00057 $0.00647
Sonnet 5 $0.00023 $0.00259
Haiku 4.5 $0.00012 $0.00129

Measured 8d ago against content hash a8631cf77897, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

nextjs-developer 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.

Origin

Copies of this mod

2 near-identical copies found in the catalogue:

skills/nextjs-developer/SKILL.md · 146 lines

How it starts

The opening of the file, as written. The whole thing — 146 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Next.js Developer

Senior Next.js developer with expertise in Next.js 14+ App Router, server components, and full-stack deployment with focus on performance and SEO excellence.

Core Workflow

  1. Architecture planning — Define app structure, routes, layouts, rendering strategy
  2. Implement routing — Create App Router structure with layouts, templates, loading/error states
  3. Data layer — Set up server components, data fetching, caching, revalidation
  4. Optimize — Images, fonts, bundles, streaming, edge runtime
  5. Deploy — Production build, environment setup, monitoring
    • Validate: run next build locally, confirm zero type errors, check NEXT_PUBLIC_* and server-only env vars are set, run Lighthouse/PageSpeed to confirm Core Web Vitals > 90

Reference Guide

Load detailed guidance based on context:

Topic Reference Load When
App Router references/app-router.md File-based routing, layouts, templates, route groups
Server Components references/server-components.md RSC patterns, streaming, client boundaries
Server Actions references/server-actions.md Form handling, mutations, revalidation
Data Fetching references/data-fetching.md fetch, caching, ISR, on-demand revalidation
Deployment references/deployment.md Vercel, self-hosting, Docker, optimization

Constraints

MUST DO (Next.js-specific)

  • Use App Router (app/ directory), never Pages Router (pages/)
  • Keep components as Server Components by default; add 'use client' only at the leaf boundary where interactivity is required
  • Use native fetch with explicit cache / next.revalidate options — do not rely on implicit caching
  • Use generateMetadata (or the static metadata export) for all SEO — never hardcode <title> or <meta> tags in JSX
  • Optimize every image with next/image; never use a plain <img> tag for content images
  • Add loading.tsx and error.tsx at every route segment that performs async data fetching

Read the full file on GitHub · 146 lines

Files

What ships with it

5 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.

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 · 146 lines · 115 tokens per session scan A a8631cf77897

Subscribe to this mod's changes

nextjs-developer is a skill published in the GitHub repository Jeffallan/claude-skills (11,347 stars, last pushed 1mo ago), licensed MIT. It adds 115 tokens to every session and 1,295 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 2026-08-30.

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