better-auth Skill

Framework-agnostic authentication and authorization framework for TypeScript. Works with any framework - Next.js, Nuxt, SvelteKit, Remix, Astro, Hono, Express.

When to Use

Use better-auth when you need:

  • Email/password authentication
  • Social OAuth (GitHub, Google, etc.)
  • Two-factor authentication (2FA)
  • Passkeys (WebAuthn)
  • Magic links
  • Multi-tenancy / Organizations
  • Framework flexibility

Quick Start

Invoke the Skill

"Use better-auth to add authentication to my Next.js app with:
- Email/password signup
- GitHub OAuth
- PostgreSQL with Drizzle"

What You Get

The skill will help you:

  1. Install and configure better-auth
  2. Set up database schema
  3. Create auth server instance
  4. Mount API routes
  5. Create client instance
  6. Implement sign-up/sign-in UI
  7. Add session management
  8. Protect routes

Common Use Cases

Basic Email/Password Auth

"Use better-auth to implement email/password authentication with:
- Auto sign-in after signup
- Email verification
- Password reset flow"

Social OAuth

"Use better-auth to add GitHub and Google OAuth to my app"

Two-Factor Authentication

"Use better-auth to add 2FA with TOTP codes and trusted devices"

Multi-Tenant Application

"Use better-auth to build multi-tenant app with:
- Organizations
- Team member invitations
- Role-based permissions"

Key Features

Authentication Methods

  • Email/Password - Traditional signup/signin
  • Social OAuth - GitHub, Google, Apple, Discord, Facebook, etc.
  • Magic Links - Passwordless email authentication
  • Passkeys - WebAuthn biometric authentication
  • 2FA/TOTP - Two-factor authentication
  • Email OTP - One-time password codes

Framework Support

  • Next.js (App Router & Pages Router)
  • Nuxt
  • SvelteKit
  • Remix
  • Astro
  • Hono
  • Express
  • Any Node.js framework

Database Support

  • PostgreSQL
  • MySQL
  • SQLite
  • MongoDB

ORM Adapters

  • Drizzle
  • Prisma
  • Kysely
  • MongoDB native

Example Implementations

Next.js App Router

"Use better-auth to set up authentication for Next.js 14 App Router with:
- Email/password
- GitHub OAuth
- PostgreSQL + Drizzle
- Protected routes middleware
- Server actions for auth"

SvelteKit

"Use better-auth to implement auth in SvelteKit with:
- Magic link authentication
- Session management
- Protected routes"

Multi-Framework

"Use better-auth to create auth system that works with both:
- Next.js frontend
- Hono API backend
- Shared PostgreSQL database"

Advanced Features

Session Management

"Use better-auth to implement:
- Server-side session validation
- Client-side session hooks
- Custom session expiration
- Remember me functionality"

Rate Limiting

"Use better-auth to add rate limiting to prevent:
- Brute force attacks
- Signup spam
- API abuse"

Email Verification

"Use better-auth to require email verification:
- Send verification emails
- Handle verification tokens
- Block unverified users"

Best Practices

Environment Variables

Always use environment variables for:

  • BETTER_AUTH_SECRET - Secret key (min 32 chars)
  • BETTER_AUTH_URL - Application URL
  • OAuth client IDs and secrets

Security

The skill ensures:

  • HTTPS in production
  • Secure cookie settings
  • CORS configuration
  • Password requirements
  • Session security

Database Migrations

After adding plugins:

npx @better-auth/cli generate
npx @better-auth/cli migrate

Plugins

Available Plugins

  • twoFactor - TOTP 2FA
  • username - Username authentication
  • magicLink - Passwordless email
  • passkey - WebAuthn biometric
  • organization - Multi-tenancy
  • emailOTP - One-time passwords
  • anonymous - Guest users

Adding Plugins

"Use better-auth to add these plugins:
- Two-factor authentication
- Organization support
- Magic link signin"

Troubleshooting

Common Issues

“Unable to find auth instance”

  • Check auth.ts location (root, lib/, utils/)
  • Verify export name

Database connection errors

  • Verify credentials
  • Check database is running
  • Ensure correct adapter

CORS errors

  • Configure corsOptions
  • Match client/server URLs

Resources

Quick Examples

Minimal Setup:

"Use better-auth for basic email/password auth with SQLite"

Production Setup:

"Use better-auth for production with:
- GitHub + Google OAuth
- Email verification
- 2FA support
- PostgreSQL
- Rate limiting
- Proper error handling"

Enterprise Setup:

"Use better-auth for enterprise app with:
- Multi-tenancy
- SSO integration
- Role-based access control
- Audit logging
- Custom session management"

Next Steps

Bottom Line: better-auth provides production-ready authentication that works with any TypeScript framework. Just invoke the skill and describe your auth requirements.