> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/nuxt/nuxt/llms.txt
> Use this file to discover all available pages before exploring further.

# plugins/

> Nuxt has a plugins system to use Vue plugins and more at the creation of your Vue application.

Nuxt automatically reads the files in the `app/plugins/` directory and loads them at the creation of the Vue application.

<Note>
  All plugins inside are auto-registered, you don't need to add them to your `nuxt.config` separately.
</Note>

<Note>
  You can use `.server` or `.client` suffix in the file name to load a plugin only on the server or client side.
</Note>

## Registered Plugins

Only files at the top level of the directory (or index files within any subdirectories) will be auto-registered as plugins.

```bash theme={null}
plugins/
  foo.ts      // scanned
  bar/
    baz.ts    // not scanned
    foz.vue   // not scanned
    index.ts  // currently scanned but deprecated
```

Only `foo.ts` and `bar/index.ts` would be registered.

To add plugins in subdirectories, you can use the [`app/plugins`](/api/nuxt-config#plugins-1) option in `nuxt.config.ts`:

```ts nuxt.config.ts theme={null}
export default defineNuxtConfig({
  plugins: [
    '~/plugins/bar/baz',
    '~/plugins/bar/foz',
  ],
})
```

## Creating Plugins

The only argument passed to a plugin is [`nuxtApp`](/api/composables/use-nuxt-app).

```ts plugins/hello.ts theme={null}
export default defineNuxtPlugin((nuxtApp) => {
  // Doing something with nuxtApp
})
```

### Object Syntax Plugins

It is also possible to define a plugin using an object syntax, for more advanced use cases. For example:

```ts plugins/hello.ts theme={null}
export default defineNuxtPlugin({
  name: 'my-plugin',
  enforce: 'pre', // or 'post'
  async setup (nuxtApp) {
    // this is the equivalent of a normal functional plugin
  },
  hooks: {
    // You can directly register Nuxt app runtime hooks here
    'app:created' () {
      const nuxtApp = useNuxtApp()
      // do something in the hook
    },
  },
  env: {
    // Set this value to `false` if you don't want the plugin to run when rendering server-only or island components.
    islands: true,
  },
})
```

<Note>
  If you are using the object-syntax, the properties are statically analyzed to produce a more optimized build. So you should not define them at runtime.
</Note>

## Registration Order

You can control the order in which plugins are registered by prefixing with 'alphabetical' numbering to the file names.

```bash theme={null}
plugins/
  01.myPlugin.ts
  02.myOtherPlugin.ts
```

In this example, `02.myOtherPlugin.ts` will be able to access anything that was injected by `01.myPlugin.ts`.

This is useful in situations where you have a plugin that depends on another plugin.

<Note>
  In case you're new to 'alphabetical' numbering, remember that filenames are sorted as strings, not as numeric values. For example, `10.myPlugin.ts` would come before `2.myOtherPlugin.ts`. This is why the example prefixes single digit numbers with `0`.
</Note>

## Loading Strategy

### Parallel Plugins

By default, Nuxt loads plugins sequentially. You can define a plugin as `parallel` so Nuxt won't wait until the end of the plugin's execution before loading the next plugin.

```ts plugins/my-plugin.ts theme={null}
export default defineNuxtPlugin({
  name: 'my-plugin',
  parallel: true,
  async setup (nuxtApp) {
    // the next plugin will be executed immediately
  },
})
```

### Plugins With Dependencies

If a plugin needs to wait for another plugin before it runs, you can add the plugin's name to the `dependsOn` array.

```ts plugins/depending-on-my-plugin.ts theme={null}
export default defineNuxtPlugin({
  name: 'depends-on-my-plugin',
  dependsOn: ['my-plugin'],
  async setup (nuxtApp) {
    // this plugin will wait for the end of `my-plugin`'s execution before it runs
  },
})
```

## Using Composables

You can use [composables](/directory-structure/composables) as well as [utils](#) within Nuxt plugins:

```ts app/plugins/hello.ts theme={null}
export default defineNuxtPlugin((nuxtApp) => {
  const foo = useFoo()
})
```

However, keep in mind there are some limitations and differences:

<Info>
  **If a composable depends on another plugin registered later, it might not work.**

  Plugins are called in order sequentially and before everything else. You might use a composable that depends on another plugin which has not been called yet.
</Info>

<Info>
  **If a composable depends on the Vue.js lifecycle, it won't work.**

  Normally, Vue.js composables are bound to the current component instance while plugins are only bound to [`nuxtApp`](/api/composables/use-nuxt-app) instance.
</Info>

## Providing Helpers

If you would like to provide a helper on the [`NuxtApp`](/api/composables/use-nuxt-app) instance, return it from the plugin under a `provide` key.

<CodeGroup>
  ```ts plugins/hello.ts theme={null}
  export default defineNuxtPlugin(() => {
    return {
      provide: {
        hello: (msg: string) => `Hello ${msg}!`,
      },
    }
  })
  ```

  ```ts plugins/hello-object-syntax.ts theme={null}
  export default defineNuxtPlugin({
    name: 'hello',
    setup () {
      return {
        provide: {
          hello: (msg: string) => `Hello ${msg}!`,
        },
      }
    },
  })
  ```
</CodeGroup>

You can then use the helper in your components:

```vue app/components/Hello.vue theme={null}
<script setup lang="ts">
// alternatively, you can also use it here
const { $hello } = useNuxtApp()
</script>

<template>
  <div>
    {{ $hello('world') }}
  </div>
</template>
```

<Info>
  Note that we highly recommend using [`composables`](/directory-structure/composables) instead of providing helpers to avoid polluting the global namespace and keep your main bundle entry small.
</Info>

## Typing Plugins

If you return your helpers from the plugin, they will be typed automatically; you'll find them typed for the return of `useNuxtApp()` and within your templates.

<Note>
  If you need to use a provided helper *within* another plugin, you can call [`useNuxtApp()`](/api/composables/use-nuxt-app) to get the typed version. But in general, this should be avoided unless you are certain of the plugins' order.
</Note>

For advanced use-cases, you can declare the type of injected properties like this:

```ts index.d.ts theme={null}
declare module '#app' {
  interface NuxtApp {
    $hello (msg: string): string
  }
}

declare module 'vue' {
  interface ComponentCustomProperties {
    $hello (msg: string): string
  }
}

export {}
```

## Vue Plugins

If you want to use Vue plugins, like [vue-gtag](https://github.com/MatteoGabriele/vue-gtag) to add Google Analytics tags, you can use a Nuxt plugin to do so.

First, install the Vue plugin dependency, then create a plugin file:

```ts app/plugins/vue-gtag.client.ts theme={null}
import VueGtag, { trackRouter } from 'vue-gtag-next'

export default defineNuxtPlugin((nuxtApp) => {
  nuxtApp.vueApp.use(VueGtag, {
    property: {
      id: 'GA_MEASUREMENT_ID',
    },
  })
  trackRouter(useRouter())
})
```

## Vue Directives

Similarly, you can register a custom Vue directive in a plugin.

```ts plugins/my-directive.ts theme={null}
export default defineNuxtPlugin((nuxtApp) => {
  nuxtApp.vueApp.directive('focus', {
    mounted (el) {
      el.focus()
    },
    getSSRProps (binding, vnode) {
      // you can provide SSR-specific props here
      return {}
    },
  })
})
```

<Warning>
  If you register a Vue directive, you *must* register it on both client and server side unless you are only using it when rendering one side. If the directive only makes sense from a client side, you can always move it to `~/plugins/my-directive.client.ts` and provide a 'stub' directive for the server in `~/plugins/my-directive.server.ts`.
</Warning>