Nuxt Better Auth

Authentication module for Nuxt 4+ built on Better Auth. Provides composables, server utilities, and route protection.

Alpha Status: This module is currently in alpha (v0.0.2-alpha.19) and not recommended for production use. APIs may change.

When to Use

Installing/configuring @onmax/nuxt-better-auth
Implementing login/signup/signout flows
Protecting routes (client and server)
Accessing user session in API routes
Integrating Better Auth plugins (admin, passkey, 2FA)
Setting up database with NuxtHub
Using clientOnly mode for external auth backends
Adding i18n support with @nuxtjs/i18n

For Nuxt patterns: use nuxt skill For NuxtHub database: use nuxthub skill

Available Guidance

File

Topics

references/installation.md

Module setup, env vars, config files

references/client-auth.md

useUserSession, signIn/signUp/signOut, BetterAuthState, safe redirects

references/server-auth.md

serverAuth, getUserSession, requireUserSession

references/route-protection.md

routeRules, definePageMeta, middleware

references/plugins.md

Better Auth plugins (admin, passkey, 2FA)

references/database.md

NuxtHub integration, Drizzle schema, custom tables with FKs

references/client-only.md

External auth backend, clientOnly mode, CORS

references/types.md

AuthUser, AuthSession, type augmentation

Loading Files

Consider loading these reference files based on your task:

references/installation.md - if installing or configuring the module
references/client-auth.md - if building login/signup/signout flows
references/server-auth.md - if protecting API routes or accessing user session server-side
references/route-protection.md - if using routeRules or definePageMeta for auth
references/plugins.md - if integrating Better Auth plugins (admin, passkey, 2FA)
references/database.md - if setting up database with NuxtHub or Drizzle
references/client-only.md - if using external auth backend with clientOnly mode
references/types.md - if working with AuthUser, AuthSession, or type augmentation

DO NOT load all files at once. Load only what's relevant to your current task.

Key Concepts

Concept

Description

useUserSession()

Client composable - user, session, loggedIn, signIn/Out methods

requireUserSession()

Server helper - throws 401/403 if not authenticated

auth route mode

'user', 'guest', { user: {...} }, or false

serverAuth()

Get Better Auth instance in server routes

Quick Reference

// Client: useUserSession()
const { user, loggedIn, signIn, signOut } = useUserSession()
await signIn.email({ email, password }, { onSuccess: () => navigateTo('/') })

// Server: requireUserSession()
const { user } = await requireUserSession(event, { user: { role: 'admin' } })

// nuxt.config.ts: Route protection
routeRules: {
  '/admin/**': { auth: { user: { role: 'admin' } } },
  '/login': { auth: 'guest' },
  '/app/**': { auth: 'user' }
}

Resources

Token efficiency: Main skill ~300 tokens, each sub-file ~800-1200 tokens

nuxt-better-auth

Nuxt Better Auth

Nuxt Better Auth

When to Use

Available Guidance

Loading Files

Key Concepts

Quick Reference

Resources