Nuxt Auth Utils

Add Authentication to Nuxt applications with secured & sealed cookies sessions.

• Release Notes
• Demo with OAuth
• Demo with Passkeys

Features

• Hybrid Rendering support (SSR / CSR / SWR / Prerendering)
• 20+ OAuth Providers
• Password Hashing
• WebAuthn (passkey)
• useUserSession() Vue composable
• Tree-shakable server utils
• <AuthState> component
• Extendable with hooks

It has few dependencies (only from UnJS), run on multiple JS environments (Node, Deno, Workers) and is fully typed with TypeScript.

Requirements

This module only works with a Nuxt server running as it uses server API routes (nuxt build).

This means that you cannot use this module with nuxt generate.

You can anyway use Hybrid Rendering to pre-render pages of your application or disable server-side rendering completely.

Quick Setup

1. Add nuxt-auth-utils in your Nuxt project

npx nuxi@latest module add auth-utils

2. Add a NUXT_SESSION_PASSWORD env variable with at least 32 characters in the .env.

# .env
NUXT_SESSION_PASSWORD=password-with-at-least-32-characters

Nuxt Auth Utils generates one for you when running Nuxt in development the first time if no NUXT_SESSION_PASSWORD is set.

3. That's it! You can now add authentication to your Nuxt app ✨

Vue Composable

Nuxt Auth Utils automatically adds some plugins to fetch the current user session to let you access it from your Vue components.

User Session

<script setup>
const { loggedIn, user, session, fetch, clear } = useUserSession()
</script>

<template>
  <div v-if="loggedIn">
    <h1>Welcome {{ user.login }}!</h1>
    <p>Logged in since {{ session.loggedInAt }}</p>
    <button @click="clear">Logout</button>
  </div>
  <div v-else>
    <h1>Not logged in</h1>
    <a href="/auth/github">Login with GitHub</a>
  </div>
</template>

TypeScript Signature:

interface UserSessionComposable {
  /**
   * Computed indicating if the auth session is ready
   */
  ready: ComputedRef<boolean>
  /**
   * Computed indicating if the user is logged in.
   */
  loggedIn: ComputedRef<boolean>
  /**
   * The user object if logged in, null otherwise.
   */
  user: ComputedRef<User | null>
  /**
   * The session object.
   */
  session: Ref<UserSession>
  /**
   * Fetch the user session from the server.
   */
  fetch: () => Promise<void>
  /**
   * Clear the user session and remove the session cookie.
   */
  clear: () => Promise<void>
}

[!IMPORTANT] Nuxt Auth Utils uses the /api/_auth/session route for session management. Ensure your API route middleware doesn't interfere with this path.

Server Utils

The following helpers are auto-imported in your server/ directory.

Session Management

// Set a user session, note that this data is encrypted in the cookie but can be decrypted with an API call
// Only store the data that allow you to recognize a user, but do not store sensitive data
// Merges new data with existing data using unjs/defu library
await setUserSession(event, {
  // User data
  user: {
    login: 'atinux'
  },
  // Private data accessible only on server/ routes
  secure: {
    apiToken: '1234567890'
  },
  // Any extra fields for the session data
  loggedInAt: new Date()
})

// Replace a user session. Same behaviour as setUserSession, except it does not merge data with existing data
await replaceUserSession(event, data)

// Get the current user session
const session = await getUserSession(event)

// Clear the current user session
await clearUserSession(event)

// Require a user session (send back 401 if no `user` key in session)
const session = await requireUserSession(event)

You can define the type for your user session by creating a type declaration file (for example, auth.d.ts) in your project to augment the UserSession type:

// auth.d.ts
declare module '#auth-utils' {
  interface User {
    // Add your own fields
  }

  interface UserSession {
    // Add your own fields
  }

  interface SecureSessionData {
    // Add your own fields
  }
}

export {}

[!IMPORTANT] Since we encrypt and store session data in cookies, we're constrained by the 4096-byte cookie size limit. Store only essential information.

OAuth Event Handlers

All handlers can be auto-imported and used in your server routes or API routes.

The pattern is defineOAuth<Provider>EventHandler({ onSuccess, config?, onError? }), example: defineOAuthGitHubEventHandler.

The helper returns an event handler that automatically redirects to the provider authorization page and then calls onSuccess or onError depending on the result.

The config can be defined directly from the runtimeConfig in your nuxt.config.ts:

export default defineNuxtConfig({
  runtimeConfig: {
    oauth: {
      // provider in lowercase (github, google, etc.)
      <provider>: {
        clientId: '...',
        clientSecret: '...'
      }
    }
  }
})

It can also be set using environment variables:

• NUXT_OAUTH_<PROVIDER>_CLIENT_ID
• NUXT_OAUTH_<PROVIDER>_CLIENT_SECRET

Provider is in uppercase (GITHUB, GOOGLE, etc.)

Supported OAuth Providers

• Auth0
• Authentik
• AWS Cognito
• Battle.net
• Discord
• Dropbox
• Facebook
• GitHub
• GitLab
• Google
• Instagram
• Keycloak
• Linear
• LinkedIn
• Microsoft
• PayPal
• Polar
• Seznam
• Spotify
• Steam
• TikTok
• Twitch
• VK
• WorkOS
• X (Twitter)
• XSUAA
• Yandex

You can add your favorite provider by creating a new file in src/runtime/server/lib/oauth/.

Example

Example: ~/server/routes/auth/github.get.ts

export default defineOAuthGitHubEventHandler({
  config: {
    emailRequired: true
  },
  async onSuccess(event, { user, tokens }) {
    await setUserSession(event, {
      user: {
        githubId: user.id
      }
    })
    return sendRedirect(event, '/')
  },
  // Optional, will return a json error and 401 status code by default
  onError(event, error) {
    console.error('GitHub OAuth error:', error)
    return sendRedirect(event, '/')
  },
})

Make sure to set the callback URL in your OAuth app settings as <your-domain>/auth/github.

If the redirect URL mismatch in production, this means that the module cannot guess the right redirect URL. You can set the NUXT_OAUTH_<PROVIDER>_REDIRECT_URL env variable to overwrite the default one.

Password Hashing

Nuxt Auth Utils provides password hashing utilities like hashPassword and verifyPassword to hash and verify passwords by using scrypt as it is supported in many JS runtime.

const hashedPassword = await hashPassword('user_password')

if (await verifyPassword(hashedPassword, 'user_password')) {
  // Password is valid
}

You can configure the scrypt options in your nuxt.config.ts:

export default defineNuxtConfig({
  modules: ['nuxt-auth-utils'],
  auth: {
    hash: {
      scrypt: {
        // See https://github.com/adonisjs/hash/blob/94637029cd526783ac0a763ec581306d98db2036/src/types.ts#L144
      }
    }
  }
})

WebAuthn (passkey)

WebAuthn (Web Authentication) is a web standard that enhances security by replacing passwords with passkeys using public key cryptography. Users can authenticate with biometric data (like fingerprints or facial recognition) or physical devices (like USB keys), reducing the risk of phishing and password breaches. This approach offers a more secure and user-friendly authentication method, supported by major browsers and platforms.

To enable WebAuthn you need to:

1. Install the peer dependencies:

npx nypm i @simplewebauthn/server@11 @simplewebauthn/browser@11

2. Enable it in your nuxt.config.ts

export default defineNuxtConfig({
  auth: {
    webAuthn: true
  }
})

Example

In this example we will implement the very basic steps to register and authenticate a credential.

The full code can be found in the playground. The example uses a SQLite database with the following minimal tables:

CREATE TABLE users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  email TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS credentials (
  userId INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
  id TEXT UNIQUE NOT NULL,
  publicKey TEXT NOT NULL,
  counter INTEGER NOT NULL,
  backedUp INTEGER NOT NULL,
  transports TEXT NOT NULL,
  PRIMARY KEY ("userId", "id")
);

• For the users table it is important to have a unique identifier such as a username or email (here we use email). When creating a new credential, this identifier is required and stored with the passkey on the user's device, password manager, or authenticator.
• The credentials table stores:
  • The userId from the users table.
  • The credential id (as unique index)
  • The credential publicKey
  • A counter. Each time a credential is used, the counter is incremented. We can use this value to perform extra security checks. More about counter can be read here. For this example, we won't be using the counter. But you should update the counter in your database with the new value.
  • A backedUp flag. Normally, credentials are stored on the generating device. When you use a password manager or authenticator, the credential is "backed up" because it can be used on multiple devices. See this section for more details.
  • The credential transports. It is an array of strings that indicate how the credential communicates with the client. It is used to show the correct UI for the user to utilize the credential. Again, see this section for more details.

The following code does not include the actual database queries, but shows the general steps to follow. The full example can be found in the playground: registration, authentication and the database setup.

// server/api/webauthn/register.post.ts
import { z } from 'zod'
export default defineWebAuthnRegisterEventHandler({
  // optional
  async validateUser(userBody, event) {
    // bonus: check if the user is already authenticated to link a credential to his account
    // We first check if the user is already authenticated by getting the session
    // And verify that the email is the same as the one in session
    const session = await getUserSession(event)
    if (session.user?.email && session.user.email !== body.userName) {
      throw createError({ statusCode: 400, message: 'Email not matching curent session' })
    }

    // If he registers a new account with credentials
    return z.object({
      // we want the userName to be a valid email
      userName: z.string().email() 
    }).parse(userBody)
  },
  async onSuccess(event, { credential, user }) {
    // The credential creation has been successful
    // We need to create a user if it does not exist
    const db = useDatabase()

    // Get the user from the database
    let dbUser = await db.sql`...`
    if (!dbUser) {
      // Store new user in database & its credentials
      dbUser = await db.sql`...`
    }

    // we now need to store the credential in our database and link it to the user
    await db.sql`...`

    // Set the user session
    await setUserSession(event, {
      user: {
        id: dbUser.id
      },
      loggedInAt: Date.now(),
    })
  },
})

// server/api/webauthn/authenticate.post.ts
export default defineWebAuthnAuthenticateEventHandler({
  // Optionally, we can prefetch the credentials if the user gives their userName during login
  async allowCredentials(event, userName) {
    const credentials = await useDatabase().sql`...`
    // If no credentials are found, the authentication cannot be completed
    if (!credentials.length)
      throw createError({ statusCode: 400, message: 'User not found' })

    // If user is found, only allow credentials that are registered
    // The browser will automatically try to use the credential that it knows about
    // Skipping the step for the user to select a credential for a better user experience
    return credentials
    // example: [{ id: '...' }]
  },
  async getCredential(event, credentialId) {
    // Look for the credential in our database
    const credential = await useDatabase().sql`...`

    // If the credential is not found, there is no account to log in to
    if (!credential)
      throw createError({ statusCode: 400, message: 'Credential not found' })

    return credential
  },
  async onSuccess(event, { credential, authenticationInfo }) {
    // The credential authentication has been successful
    // We can look it up in our database and get the corresponding user
    const db = useDatabase()
    const user = await db.sql`...`

    // Update the counter in the database (authenticationInfo.newCounter)
    await db.sql`...`

    // Set the user session
    await setUserSession(event, {
      user: {
        id: user.id
      },
      loggedInAt: Date.now(),
    })
  },
})

[!IMPORTANT] Webauthn uses challenges to prevent replay attacks. By default, this module does not make use if this feature. If you want to use challenges (which is highly recommended), the storeChallenge and getChallenge functions are provided. An attempt ID is created and sent with each authentication request. You can use this ID to store the challenge in a database or KV store as shown in the example below.

export default defineWebAuthnAuthenticateEventHandler({
  async storeChallenge(event, challenge, attemptId) {
    // Store the challenge in a KV store or DB
    await useStorage().setItem(`attempt:${attemptId}`, challenge)
  },
  async getChallenge(event, attemptId) {
    const challenge = await useStorage().getItem(`attempt:${attemptId}`)

    // Make sure to always remove the attempt because they are single use only!
    await useStorage().removeItem(`attempt:${attemptId}`)

    if (!challenge)
      throw createError({ statusCode: 400, message: 'Challenge expired' })

    return challenge
  },
  async onSuccess(event, { authenticator }) {
    // ...
  },
})

On the frontend it is as simple as:

<script setup lang="ts">
const { register, authenticate } = useWebAuthn({
  registerEndpoint: '/api/webauthn/register', // Default
  authenticateEndpoint: '/api/webauthn/authenticate', // Default
})
const { fetch: fetchUserSession } = useUserSession()

const userName = ref('')
async function signUp() {
  await register({ userName: userName.value })
    .then(fetchUserSession) // refetch the user session
}

async function signIn() {
  await authenticate(userName.value)
    .then(fetchUserSession) // refetch the user session
}
</script>

<template>
  <form @submit.prevent="signUp">
    <input v-model="userName" placeholder="Email or username" />
    <button type="submit">Sign up</button>
  </form>
  <form @submit.prevent="signIn">
    <input v-model="userName" placeholder="Email or username" />
    <button type="submit">Sign in</button>
  </form>
</template>

Take a look at the WebAuthnModal.vue for a full example.

Demo

A full demo can be found on https://todo-passkeys.nuxt.dev using Drizzle ORM and NuxtHub.

The source code of the demo is available on https://github.com/atinux/todo-passkeys.

Extend Session

We leverage hooks to let you extend the session data with your own data or log when the user clears the session.

// server/plugins/session.ts
export default defineNitroPlugin(() => {
  // Called when the session is fetched during SSR for the Vue composable (/api/_auth/session)
  // Or when we call useUserSession().fetch()
  sessionHooks.hook('fetch', async (session, event) => {
    // extend User Session by calling your database
    // or
    // throw createError({ ... }) if session is invalid for example
  })

  // Called when we call useUserSession().clear() or clearUserSession(event)
  sessionHooks.hook('clear', async (session, event) => {
    // Log that user logged out
  })
})

Server-Side Rendering

You can make authenticated requests both from the client and the server. However, you must use useRequestFetch() to make authenticated requests during SSR if you are not using useFetch()

<script setup lang="ts">
// When using useAsyncData
const { data } = await useAsyncData('team', () => useRequestFetch()('/api/protected-endpoint'))

// useFetch will automatically use useRequestFetch during SSR
const { data } = await useFetch('/api/protected-endpoint')
</script>

There's an open issue to include credentials in $fetch in Nuxt.

Hybrid Rendering

When using Nuxt routeRules to prerender or cache your pages, Nuxt Auth Utils will not fetch the user session during prerendering but instead fetch it on the client-side (after hydration).

This is because the user session is stored in a secure cookie and cannot be accessed during prerendering.

This means that you should not rely on the user session during prerendering.

<AuthState> component

You can use the <AuthState> component to safely display auth-related data in your components without worrying about the rendering mode.

One common use case if the Login button in the header:

<template>
  <header>
    <AuthState v-slot="{ loggedIn, clear }">
      <button v-if="loggedIn" @click="clear">Logout</button>
      <NuxtLink v-else to="/login">Login</NuxtLink>
    </AuthState>
  </header>
</template>

If the page is cached or prerendered, nothing will be rendered until the user session is fetched on the client-side.

You can use the placeholder slot to show a placeholder on server-side and while the user session is being fetched on client-side for the prerendered pages:

<template>
  <header>
    <AuthState>
      <template #default="{ loggedIn, clear }">
        <button v-if="loggedIn" @click="clear">Logout</button>
        <NuxtLink v-else to="/login">Login</NuxtLink>
      </template>
      <template #placeholder>
        <button disabled>Loading...</button>
      </template>
    </AuthState>
  </header>
</template>

If you are caching your routes with routeRules, please make sure to use Nitro >= 2.9.7 to support the client-side fetching of the user session.

Configuration

We leverage runtimeConfig.session to give the defaults option to h3 useSession.

You can overwrite the options in your nuxt.config.ts:

export default defineNuxtConfig({
  modules: ['nuxt-auth-utils'],
  runtimeConfig: {
    session: {
      maxAge: 60 * 60 * 24 * 7 // 1 week
    }
  }
})

Our defaults are:

{
  name: 'nuxt-session',
  password: process.env.NUXT_SESSION_PASSWORD || '',
  cookie: {
    sameSite: 'lax'
  }
}

You can also overwrite the session config by passing it as 3rd argument of the setUserSession and replaceUserSession functions:

await setUserSession(event, { ... } , {
  maxAge: 60 * 60 * 24 * 7 // 1 week
})

Checkout the SessionConfig for all options.

More

• nuxt-authorization: Authorization module for managing permissions inside a Nuxt app, compatible with nuxt-auth-utils

Development

# Install dependencies
npm install

# Generate type stubs
npm run dev:prepare

# Develop with the playground
npm run dev

# Build the playground
npm run dev:build

# Run ESLint
npm run lint

# Run Vitest
npm run test
npm run test:watch

# Release new version
npm run release