Nuxt core

Nuxt 5 Core Fundamentals

Project setup, configuration, routing, SEO, and error handling for Nuxt 5 applications.

Quick Reference

Version Requirements

Package	Minimum	Recommended
nuxt	5.0.0	5.x
vue	3.5.0	3.5.x
nitro	3.0.0	3.x
vite	8.0.0	8.x
typescript	5.0.0	5.x

Key Commands

bunx nuxi@latest init my-app
bun run dev
bun run build
bun run preview
bun run postinstall
bunx nuxi typecheck
bunx nuxi add page about
bunx nuxi add component MyButton
bunx nuxi add composable useAuth

Secure Installation

Scaffolding tools like bunx nuxi init download and execute remote code. Before running, follow supply chain security best practices:

• Block post-install scripts — npm config set ignore-scripts true (or Bun: disabled by default)
• Cooldown period — Wait 7 days for new package versions to be vetted by the community
• Audit before installing — Run socket package score npm <pkg> or use socket npm install <pkg> to check packages

Load the dependency-upgrade skill for full security configuration including Socket CLI integration, cooldown setup, lockfile validation, and CI enforcement.

Directory Structure (Nuxt v5)

my-nuxt-app/
├── app/                    # Default srcDir
│   ├── assets/             # Build-processed assets (CSS, images)
│   ├── components/         # Auto-imported Vue components
│   ├── composables/        # Auto-imported composables
│   ├── layouts/            # Layout components
│   ├── middleware/         # Route middleware
│   ├── pages/              # File-based routing
│   ├── plugins/            # Nuxt plugins
│   ├── utils/              # Auto-imported utility functions
│   ├── app.vue             # Main app component
│   ├── app.config.ts       # App-level runtime config
│   ├── error.vue           # Error page component
│   └── router.options.ts   # Router configuration
│
├── server/                 # Server-side code (Nitro v3)
│   ├── api/                # API endpoints
│   ├── middleware/         # Server middleware
│   ├── plugins/            # Nitro plugins
│   ├── routes/             # Server routes
│   └── utils/              # Server utilities
│
├── shared/                 # Shared code (app + server)
│   ├── utils/              # Auto-imported shared utils
│   └── types/              # Auto-imported shared types
│
├── public/                 # Static assets (served from root)
├── content/                # Nuxt Content files (if using)
├── layers/                 # Nuxt layers
├── modules/                # Local modules
├── .nuxt/                  # Generated files (git ignored)
├── .output/                # Build output (git ignored)
├── nuxt.config.ts          # Nuxt configuration
├── tsconfig.json           # TypeScript configuration
└── package.json            # Dependencies

What's New in Nuxt 5

Area	Nuxt 4	Nuxt 5
Bundler	Vite 6 (esbuild + Rollup)	Vite 8 (Rolldown)
Server engine	Nitro v2 (h3 v1)	Nitro v3 (h3 v2, Web Standard APIs)
Vite config	Separate client/server configs	Vite Environment API
JS runtime	JSX plugin included by default	JSX plugin optional (on-demand)
Client-only placeholder	Empty <div>	HTML comment node
callHook	Always returns Promise	May return void (sync when possible)
clearNuxtState	Sets to undefined	Resets to initial default value
Page component names	Auto-generated	Normalized to match route names
experimental.externalVue	Available	Removed (always mocked)

Configuration

Basic nuxt.config.ts

export default defineNuxtConfig({
  future: {
    compatibilityVersion: 5
  },

  devtools: { enabled: true },

  modules: [
    '@nuxt/ui',
    '@nuxt/content',
    '@nuxt/image'
  ],

  runtimeConfig: {
    apiSecret: process.env.API_SECRET,
    databaseUrl: process.env.DATABASE_URL,

    public: {
      apiBase: process.env.API_BASE || 'https://api.example.com',
      appName: 'My App'
    }
  },

  app: {
    head: {
      title: 'My Nuxt App',
      meta: [
        { charset: 'utf-8' },
        { name: 'viewport', content: 'width=device-width, initial-scale=1' }
      ]
    }
  },

  nitro: {
    preset: 'cloudflare_pages'
  },

  typescript: {
    strict: true,
    typeCheck: true
  }
})

Vite 8 / Rolldown Configuration

Nuxt 5 uses Vite 8 with Rolldown as the bundler. Use rolldownOptions instead of rollupOptions:

export default defineNuxtConfig({
  vite: {
    build: {
      rolldownOptions: {
        output: {
          manualChunks: {
            vendor: ['vue', 'vue-router']
          }
        }
      }
    },

    optimizeDeps: {
      include: []
    }
  }
})

Vite Environment API

Nuxt 5 uses the Vite Environment API for environment-specific config. Use configEnvironment and applyToEnvironment instead of separate client/server configs:

// Module/plugin authors - use Vite plugins instead of extendViteConfig
addVitePlugin(() => ({
  name: 'my-plugin',
  config(config) {
    // Global vite configuration
  },
  configEnvironment(name, config) {
    // Environment-specific config
    if (name === 'client') {
      config.optimizeDeps ||= {}
      config.optimizeDeps.include ||= []
      config.optimizeDeps.include.push('my-package')
    }
  },
  applyToEnvironment(environment) {
    return environment.name === 'client'
  },
}))

Optional JSX Support

@vitejs/plugin-vue-jsx is no longer installed by default. Install it only if needed:

bun add -D @vitejs/plugin-vue-jsx

Nuxt will auto-detect .jsx/.tsx files and prompt installation.

Runtime Config Usage

const config = useRuntimeConfig()
const apiBase = config.public.apiBase
const apiSecret = config.apiSecret

In server routes (v5 change): useRuntimeConfig() no longer accepts event:

// Nuxt 4
export default defineEventHandler((event) => {
  const config = useRuntimeConfig(event)
})

// Nuxt 5
export default defineEventHandler(() => {
  const config = useRuntimeConfig()
})

App Config vs Runtime Config

Feature	App Config	Runtime Config
Location	app.config.ts	nuxt.config.ts
Hot reload	Yes	No
Secrets	No	Yes (server-only)
Use case	UI settings, themes	API keys, URLs

Routing

File-Based Routing

app/pages/
├── index.vue              → /
├── about.vue              → /about
├── users/
│   ├── index.vue          → /users
│   └── [id].vue           → /users/:id
└── blog/
    ├── index.vue          → /blog
    ├── [slug].vue         → /blog/:slug
    └── [...slug].vue      → /blog/* (catch-all)

v5 Change: Page component names are now normalized to match their route names. This ensures consistent <KeepAlive> behavior.

Dynamic Routes

<!-- app/pages/users/[id].vue -->
<script setup lang="ts">
const route = useRoute()
const userId = computed(() => route.params.id)
const { data: user } = await useFetch(`/api/users/${userId.value}`)
</script>

<template>
  <div>
    <h1>{{ user?.name }}</h1>
  </div>
</template>

Navigation

<script setup>
const goToUser = (id: string) => {
  navigateTo(`/users/${id}`)
}
</script>

<template>
  <NuxtLink to="/about">About</NuxtLink>
  <NuxtLink :to="`/users/${user.id}`">View User</NuxtLink>
  <NuxtLink to="/dashboard" prefetch>Dashboard</NuxtLink>
</template>

Route Middleware

// app/middleware/auth.ts
export default defineNuxtRouteMiddleware((to, from) => {
  const { isAuthenticated } = useAuth()

  if (!isAuthenticated.value) {
    return navigateTo('/login')
  }
})

<!-- app/pages/dashboard.vue -->
<script setup lang="ts">
definePageMeta({
  middleware: 'auth'
})
</script>

Global Middleware

// app/middleware/analytics.global.ts
export default defineNuxtRouteMiddleware((to, from) => {
  if (import.meta.client) {
    window.gtag?.('event', 'page_view', {
      page_path: to.path
    })
  }
})

SEO & Meta Tags

useSeoMeta (Recommended)

<script setup lang="ts">
useSeoMeta({
  title: 'My Page Title',
  description: 'Page description for search engines',
  ogTitle: 'My Page Title',
  ogDescription: 'Page description',
  ogImage: 'https://example.com/og-image.jpg',
  ogUrl: 'https://example.com/my-page',
  twitterCard: 'summary_large_image'
})
</script>

Dynamic Meta Tags

<script setup lang="ts">
const { data: post } = await useFetch(`/api/posts/${route.params.slug}`)

useSeoMeta({
  title: () => post.value?.title,
  description: () => post.value?.excerpt,
  ogImage: () => post.value?.image
})
</script>

Error Handling

Error Page

<!-- app/error.vue -->
<script setup lang="ts">
import type { NuxtError } from '#app'

const props = defineProps<{
  error: NuxtError
}>()

const handleError = () => {
  clearError({ redirect: '/' })
}
</script>

<template>
  <div class="error-page">
    <h1>{{ error.statusCode }}</h1>
    <p>{{ error.message }}</p>
    <button @click="handleError">Go Home</button>
  </div>
</template>

Throwing Errors (App-side)

In the Vue part of your app (the app/ directory), createError continues to work:

throw createError({
  statusCode: 404,
  statusMessage: 'Page Not Found',
  fatal: true
})

Error Boundaries (Component-Level)

<template>
  <NuxtErrorBoundary @error="handleError">
    <template #error="{ error, clearError }">
      <div>
        <h2>Something went wrong</h2>
        <p>{{ error.message }}</p>
        <button @click="clearError">Try again</button>
      </div>
    </template>
    <MyComponent />
  </NuxtErrorBoundary>
</template>

clearNuxtState Resets to Defaults (v5 Change)

// Nuxt 4: clearNuxtState sets state to undefined
// Nuxt 5: clearNuxtState resets state to its initial value

const count = useState('counter', () => 42)
count.value = 100

clearNuxtState('counter')
// Nuxt 5: count.value is now 42 (the default), not undefined

Common Anti-Patterns

Using process.env Instead of Runtime Config

// WRONG
const apiUrl = process.env.API_URL

// CORRECT
const config = useRuntimeConfig()
const apiUrl = config.public.apiBase

Missing Middleware Return

// WRONG
export default defineNuxtRouteMiddleware((to) => {
  if (!isAuthenticated.value) {
    navigateTo('/login')  // Missing return!
  }
})

// CORRECT
export default defineNuxtRouteMiddleware((to) => {
  if (!isAuthenticated.value) {
    return navigateTo('/login')
  }
})

Non-Reactive Route Params

// WRONG
const userId = route.params.id

// CORRECT
const userId = computed(() => route.params.id)

Troubleshooting

Build Errors / Type Errors:

rm -rf .nuxt .output node_modules/.vite && bun install && bun run dev

Route Not Found:

• Check file is in app/pages/
• Verify file extension is .vue
• Check for typos in dynamic params [id].vue

Vite Plugin Warnings:

• Use configEnvironment + applyToEnvironment instead of server/client options
• Deprecated extendViteConfig({ server }) will show warnings

JSX Not Working:

• Install @vitejs/plugin-vue-jsx if using .jsx/.tsx files

Related Skills

• nuxt-data: Composables, data fetching, state management
• nuxt-server: Server routes, API patterns (Nitro v3)
• nuxt-production: Performance, testing, deployment, migration

Templates Available

See templates/ directory for:

• Production-ready nuxt.config.ts
• app.vue with proper structure

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Version: 5.0.0 | Last Updated: 2026-03-30 | License: MIT