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Plugins and Middleware

Learn how to migrate from Nuxt 2 to Nuxt 3 plugins and middleware.

Plugins

Plugins now have a different format, and take only one argument (nuxtApp).

export default (ctx, inject) => {
  inject('injected', () => 'my injected function')
})
Read more in Docs > Guide > Directory Structure > Plugins.
Read more about the format of nuxtApp.

Migration

  1. Migrate your plugins to use the defineNuxtPlugin helper function.
  2. Remove any entries in your nuxt.config plugins array that are located in your plugins/ folder. All files in this directory at the top level (and any index files in any subdirectories) will be automatically registered. Instead of setting mode to client or server, you can indicate this in the file name. For example, ~/plugins/my-plugin.client.ts will only be loaded on client-side.

Route Middleware

Route middleware has a different format.

export default function ({ store, redirect }) {
  // If the user is not authenticated
  if (!store.state.authenticated) {
    return redirect('/login')
  }
}

Much like Nuxt 2, route middleware placed in your ~/middleware folder is automatically registered. You can then specify it by name in a component. However, this is done with definePageMeta rather than as a component option.

navigateTo is one of a number of route helper functions.

Read more in Docs > Guide > Directory Structure > Middleware.

Migration

  1. Migrate your route middleware to use the defineNuxtRouteMiddleware helper function.
  2. Any global middleware (such as in your nuxt.config) can be placed in your ~/middleware folder with a .global extension, for example ~/middleware/auth.global.ts.