Guide Key Concepts
Auto-imports
Nuxt auto-imports components, composables, helper functions and Vue APIs.
Nuxt auto-imports components, composables and Vue.js APIs to use across your application without explicitly importing them.
<script setup lang="ts">const count = ref(1) // ref is auto-imported</script>
Thanks to its opiniated directory structure, Nuxt can auto-import your components/
, composables/
and utils/
.
Contrary to a classic global declaration, Nuxt preserves typings, IDEs completions and hints, and only includes what is used in your production code.
server
directory, Nuxt auto-imports exported functions and variables from server/utils/
.imports
section of your nuxt.config
file.Built-in Auto-imports
Nuxt auto-imports functions and composables to perform data fetching, get access to the app context and runtime config, manage state or define components and plugins.
<script setup lang="ts">/* useAsyncData() and $fetch() are auto-imported */const { data, refresh, pending } = await useFetch('/api/hello')</script>
Vue 3 exposes Reactivity APIs like ref
or computed
, as well as lifecycle hooks and helpers that are auto-imported by Nuxt.
<script setup lang="ts">/* ref() and computed() are auto-imported */const count = ref(1)const double = computed(() => count.value * 2)</script>
Vue and Nuxt composables
When you are using the built-in Composition API composables provided by Vue and Nuxt, be aware that many of them rely on being called in the right context.
During a component lifecycle, Vue tracks the temporary instance of the current component (and similarly, Nuxt tracks a temporary instance of nuxtApp
) via a global variable, and then unsets it in same tick. This is essential when server rendering, both to avoid cross-request state pollution (leaking a shared reference between two users) and to avoid leakage between different components.
That means that (with very few exceptions) you cannot use them outside a Nuxt plugin, Nuxt route middleware or Vue setup function. On top of that, you must use them synchronously - that is, you cannot use await
before calling a composable, except within <script setup>
blocks, within the setup function of a component declared with defineNuxtComponent
, in defineNuxtPlugin
or in defineNuxtRouteMiddleware
, where we perform a transform to keep the synchronous context even after the await
.
If you get an error message like Nuxt instance is unavailable
then it probably means you are calling a Nuxt composable in the wrong place in the Vue or Nuxt lifecycle.
Example of breaking code:
// trying to access runtime config outside a composableconst config = useRuntimeConfig()export const useMyComposable = () => { // accessing runtime config here}
Example of working code:
export const useMyComposable = () => { // Because your composable is called in the right place in the lifecycle, // useRuntimeConfig will also work const config = useRuntimeConfig() // ...}
Directory-based Auto-imports
Nuxt directly auto-imports files created in defined directories:
components/
for Vue components.composables/
for Vue composables.utils/
for helper functions and other utilities.
Explicit Imports
Nuxt exposes every auto-import with the #imports
alias that can be used to make the import explicit if needed:
<script setup lang="ts">import { ref, computed } from '#imports'const count = ref(1)const double = computed(() => count.value * 2)</script>
Disabling Auto-imports
If you want to disable auto-importing composables and utilities, you can set imports.autoImport
to false
in the nuxt.config
file.
export default defineNuxtConfig({ imports: { autoImport: false }})
This will disable auto-imports completely but it's still possible to use explicit imports from #imports
.
Auto-imported Components
Nuxt also automatically imports components from your ~/components
directory, although this is configured separately from auto-importing composables and utility functions.
To disable auto-importing components from your own ~/components
directory, you can set components.dirs
to an empty array (though note that this will not affect components added by modules).
export default defineNuxtConfig({ components: { dirs: [] }})
Auto-import from third-party packages
Nuxt also allows auto-importing from third-party packages.
For example, you could enable the auto-import of the useI18n
composable from the vue-i18n
package like this:
export default defineNuxtConfig({ imports: { presets: [ { from: 'vue-i18n', imports: ['useI18n'] } ] }})