Next.js 16 Expert

Production-ready React framework with Server Components, streaming, and Turbopack.

Agent Workflow (MANDATORY)

Before ANY implementation, launch in parallel:

1. fuse-ai-pilot:explore-codebase – Analyze existing routes, components, and patterns
2. fuse-ai-pilot:research-expert – Verify latest Next.js 16 docs via Context7/Exa
3. mcp__context7__query-docs – Check breaking changes v15→v16

After implementation, run fuse-ai-pilot:sniper for validation.

Overview

When to Use

• Building new React applications with server-first architecture
• Need Server Components for optimal performance and SEO
• Implementing streaming and progressive rendering
• Migrating from Next.js 14/15 to version 16
• Using proxy.ts for route protection (replaces middleware)
• Leveraging Turbopack for faster development builds

Why Next.js 16

Breaking Changes from v15

Critical Migration Points

1. proxy.ts replaces middleware.ts – Full Node.js runtime, not Edge
2. Turbopack ONLY – Webpack completely deprecated and removed
3. use cache directive – Replaces Partial Prerendering (PPR)
4. React 19 required – New hooks and View Transitions API
5. Async params/searchParams – Must await dynamic route params

SOLID Architecture

Module-Based Structure

Pages are thin entry points importing from feature modules:

• app/page.tsx → imports from modules/public/home/
• app/dashboard/page.tsx → imports from modules/auth/dashboard/
• modules/cores/ → Shared services, utilities, configurations

File Conventions

• page.tsx – Route UI component
• layout.tsx – Shared UI wrapper
• loading.tsx – Suspense loading state
• error.tsx – Error boundary
• not-found.tsx – 404 handling

Core Concepts

Server Components (Default)

All components are Server Components by default. Use 'use client' directive only when needed for interactivity, hooks, or browser APIs.

Caching Strategy

• use cache – Mark async functions for caching
• cacheTag() – Tag cached data for targeted revalidation
• cacheLife() – Control cache duration (stale, revalidate, expire)
• revalidateTag() – Invalidate cached data on-demand

Data Fetching

Server Components fetch data directly. Use fetch() with native caching or database queries. No need for getServerSideProps or getStaticProps.

Reference Guide

Best Practices

1. Server Components first – Only add 'use client' when necessary
2. Colocate data fetching – Fetch data where it’s used
3. Streaming with Suspense – Wrap slow components in Suspense
4. proxy.ts over middleware – Full Node.js runtime for auth
5. Cache explicitly – Use use cache for expensive operations
6. Parallel routes – Load independent UI sections simultaneously

Performance

Build Optimization

• Turbopack – Incremental compilation, instant HMR
• React Compiler – Automatic memoization
• Tree shaking – Unused code elimination
• Code splitting – Automatic route-based splitting

Runtime Optimization

• Streaming – Progressive HTML rendering
• Partial hydration – Only hydrate interactive components
• Image optimization – Automatic WebP/AVIF conversion
• Font optimization – Zero layout shift with next/font