Nuxt/docs/2.guide/1.concepts/1.auto-imports.md

description
Nuxt auto-imports helper functions, composables and Vue APIs.

Auto-imports

Composables and Helper Functions

Nuxt auto-imports helper functions, composables and Vue APIs to use across your application without explicitly importing them. Based on the directory structure, every Nuxt application can also use auto-imports for its own components, composables and plugins. Components, composables or plugins can use these functions.

Contrary to a classic global declaration, Nuxt preserves typings and IDEs completions and hints, and only includes what is actually used in your production code.

::alert{type=info icon=💡} In the documentation, every function that is not explicitly imported is auto-imported by Nuxt and can be used as-is in your code. You can find a reference for auto-imported composables and utilities in the API section. ::

::alert{type=info} In the server directory, we auto import exported functions and variables from server/utils/. ::

::alert You can also auto-import functions exported from custom folders or third-party packages by configuring the imports section of your nuxt.config file. ::

Built-in Auto-imports

Nuxt 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>
  /* useAsyncData() and $fetch() are auto-imported */
  const { data, refresh, pending } = await useAsyncData('/api/hello', () => $fetch('/api/hello'))
</script>

Vue Auto-imports

Vue 3 exposes Reactivity APIs like ref or computed, as well as lifecycle hooks and helpers that are auto-imported by Nuxt.

<script setup>
  /* ref() and computed() are auto-imported */
  const count = ref(1)
  const double = computed(() => count.value * 2)
</script>

Using 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.

See the full explanation in this comment.

::NeedContribution ::

Example

Example: Breaking code:

// trying to access runtime config outside a composable
const config = useRuntimeConfig()

export const useMyComposable = () => {
  // accessing runtime config here
}

Example: Fixing the error:

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>
  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.

:ReadMore{link="/docs/guide/directory-structure/components"}

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: []
  }
})