nextjs-performance

nextjs-performance is a skill for Claude Code from giuseppe-trisciuoglio/developer-kit. It costs 101 tokens per session (2,959 once invoked), scanned A, original, MIT.

A performance guide for Next.js, a framework for building React websites and web applications. It covers page loading, images, fonts, caching, server-rendered parts, and JavaScript bundle size.

In plain words
What is it for?
Use it to optimize images, fonts, caching, data loading, server components, streaming, code splitting, and search-engine metadata.
Why use it?
It helps find causes of slow pages and poor Core Web Vitals, which are Google's measures of loading speed, responsiveness, and visual stability.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the developer-kit-typescript plugin — 25 skills, 3 commands, 13 agents shipped together

Good fit Use it to optimize images, fonts, caching, data loading, server components, streaming, code splitting, and search-engine metadata.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/giuseppe-trisciuoglio/developer-kit/nextjs-performance
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.

Any agent
npx skills add giuseppe-trisciuoglio/developer-kit --skill nextjs-performance
Clone the repo
git clone --depth 1 https://github.com/giuseppe-trisciuoglio/developer-kit

Made for: Claude Code.

Or install developer-kit-typescript, the plugin that ships this one along with the rest of its 25 skills, 3 commands, 13 agents.

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-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/giuseppe-trisciuoglio/developer-kit/nextjs-performance/github.svg)](https://agentmods.dev/skills/giuseppe-trisciuoglio/developer-kit/nextjs-performance)
Your own site
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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 nextjs-performance

Your own site · 80×15
<a href="https://agentmods.dev/skills/giuseppe-trisciuoglio/developer-kit/nextjs-performance"><img src="https://agentmods.dev/badge/skills/giuseppe-trisciuoglio/developer-kit/nextjs-performance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,959 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 18 Mar 2026
  • Snyk pass 18 Mar 2026
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 $0.00101 $0.02959
Opus 5 $0.00051 $0.01479
Sonnet 5 $0.00020 $0.00592
Haiku 4.5 $0.00010 $0.00296

Measured today against content hash 1c6b81a7cf1c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

nextjs-performance 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 today.

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.

plugins/developer-kit-typescript/skills/nextjs-performance/SKILL.md · 409 lines

How it starts

The opening of the file, as written. The whole thing — 409 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Next.js Performance Optimization

Expert guidance for optimizing Next.js applications with focus on Core Web Vitals, modern patterns, and best practices.

Overview

This skill provides comprehensive guidance for optimizing Next.js applications. It covers Core Web Vitals optimization (LCP, INP, CLS), modern React patterns, Server Components, caching strategies, and bundle optimization techniques. Designed for developers already familiar with React/Next.js who want to implement production-grade optimizations.

When to Use

Use this skill when working on Next.js applications and need to:

  • Optimize Core Web Vitals (LCP, INP, CLS) for better performance and SEO
  • Implement image optimization with next/image for faster loading
  • Configure font optimization with next/font to eliminate layout shift
  • Set up caching strategies using unstable_cache, revalidateTag, or ISR
  • Convert Client Components to Server Components for reduced bundle size
  • Implement Suspense streaming for progressive page loading
  • Analyze and reduce bundle size with code splitting and dynamic imports
  • Configure metadata and SEO for better search engine visibility
  • Optimize API route handlers for better performance
  • Apply Next.js 16 and React 19 modern patterns

Coverage Areas

  • Core Web Vitals optimization (LCP, INP, CLS)
  • Image optimization with next/image
  • Font optimization with next/font
  • Caching strategies (unstable_cache, revalidateTag, ISR)
  • Server Components patterns and Client-to-Server conversion
  • Streaming and Suspense for progressive loading
  • Bundle optimization and code splitting
  • Metadata and SEO configuration
  • Route handlers optimization
  • Next.js 16 + React 19 patterns

Instructions

Before Starting

  1. Analyze current performance with Lighthouse
  2. Identify bottlenecks - check Core Web Vitals in Chrome DevTools or PageSpeed Insights
  3. Determine optimization priority:
    • LCP issues → Focus on images, fonts
    • INP issues → Reduce JS, use Server Components
    • CLS issues → Add dimensions, use next/font

Read the full file on GitHub · 409 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. today First seen · 409 lines · 101 tokens per session scan A 1c6b81a7cf1c

Subscribe to this mod's changes

nextjs-performance is a skill published in the GitHub repository giuseppe-trisciuoglio/developer-kit (343 stars, last pushed yesterday), licensed MIT. It adds 101 tokens to every session and 2,959 once invoked, about $0.0005 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 2026-09-10.

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