AI Coding Skills for Next.js

Builds a production-ready Next.js 15 app with App Router, Server Components, authentication, Prisma database, and a full dashboard UI from a description or brief. Triggers on: "next.js app", "nextjs app", "build a web app", "saas dashboard", "build a dashboard", "next.js project", "scaffold nextjs", "react web app with backend", "full-stack web app", "admin panel", "create a next app", "build a saas", "web application", "nextjs starter".

Structure Next.js projects with Feature-Sliced Design layers, domain-grouped slices, and strict import hierarchy. Use when organizing features into FSD layers, enforcing slice boundaries, or keeping page.tsx thin. (triggers: src/features/**, src/entities/**, src/widgets/**, FSD, Feature Sliced Design, slices, segments)

Senior Front-End Developer expertise in ReactJS, NextJS, JavaScript, TypeScript, HTML, CSS, and modern UI/UX frameworks

Optimize images, fonts, scripts, and metadata for Next.js performance and Core Web Vitals. Use when configuring next/image for LCP, next/font for zero layout shift, next/script loading strategies, or generateMetadata for SEO.

Expert in TypeScript, Node.js, Next.js App Router, React, Shadcn UI, Radix UI and Tailwind

Secure token storage (HttpOnly Cookies) and Middleware patterns. Use when implementing authentication, secure session storage, or auth middleware in Next.js. (triggers: middleware.ts, **/auth.ts, **/login/page.tsx, cookie, jwt, session, localstorage, auth)

Implement secure Next.js Server Actions for mutations, forms, and optimistic UI. Use when building actions, form flows, auth checks, or revalidation after writes.

Comprehensive Next.js, React, Redux, and TypeScript development guidelines covering SOLID principles, component architecture, and best practices.

Best practices for multi-language handling, locale routing, and detection strategies across App and Pages Router. Use when adding i18n, locale routing, or language detection in Next.js.

Write Jest or Vitest unit tests with React Testing Library and Playwright E2E tests for Next.js projects. Use when testing components with RTL, mocking APIs with MSW, or creating Playwright user flow tests. (triggers: **/*.test.{ts,tsx}, cypress/**, tests/**, jest.config.*, vitest, playwright, msw, testing-library)

Select and implement SSG, SSR, ISR, Streaming, or Partial Prerendering strategies in Next.js App Router. Use when choosing a rendering mode for a page, configuring generateStaticParams, or enabling PPR. (triggers: **/page.tsx, **/layout.tsx, generateStaticParams, dynamic, dynamicParams, PPR, streaming)

Configure Next.js cache layers, invalidation, and cache-component APIs. Use when choosing `fetch` caching, `use cache`, tags, or stale-data debugging in Next.js.

Build secure, reusable data access patterns with DTOs, taint checks, and colocated authorization in Next.js. Use when centralizing database queries, transforming raw data to DTOs, adding server-only guards, or preventing sensitive data from reaching Client Components.

Implement Pages Router data fetching with getServerSideProps, getStaticProps, and API routes in Next.js legacy projects. Use when working in a pages/ directory project, adding SSR/SSG data fetching, or creating API routes.

Apply best practices for managing URL, server, and client state in Next.js applications. Use when choosing between URL params, SWR/TanStack Query, Zustand, or Context for state, or when fixing hydration mismatches from localStorage. (triggers: **/hooks/*.ts, **/store.ts, **/components/*.tsx, useState, useContext, zustand, redux)

Master Next.js 14+ App Router with Server Components, streaming, parallel routes, and advanced data fetching. Use when building Next.js applications, implementing SSR/SSG, or optimizing React Server Components.

Secure Next.js App Router with middleware auth, Server Action validation, CSP headers, and taint APIs. Use when adding authentication middleware, validating Server Action inputs with Zod, or preventing secret leakage to client bundles. (triggers: app/**/actions.ts, middleware.ts, action, boundary, sanitize, auth, jose)

Full Sentry SDK setup for Next.js. Use when asked to "add Sentry to Next.js", "install @sentry/nextjs", or configure error monitoring, tracing, session replay, logging, profiling, AI monitoring, or crons for Next.js applications. Supports Next.js 13+ with App Router and Pages Router.