
better-auth
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SKILL.md
name: better-auth description: Implement authentication and authorization with Better Auth - a framework-agnostic TypeScript authentication framework. Features include email/password authentication with verification, OAuth providers (Google, GitHub, Discord, etc.), two-factor authentication (TOTP, SMS), passkeys/WebAuthn support, session management, role-based access control (RBAC), rate limiting, and database adapters. Use when adding authentication to applications, implementing OAuth flows, setting up 2FA/MFA, managing user sessions, configuring authorization rules, or building secure authentication systems for web applications. license: MIT version: 2.0.0
Better Auth Skill
Better Auth is comprehensive, framework-agnostic authentication/authorization framework for TypeScript with built-in email/password, social OAuth, and powerful plugin ecosystem for advanced features.
Quick Start
Installation
Environment Setup
Create .env:
BETTER_AUTH_SECRET=<generated-secret-32-chars-min>
BETTER_AUTH_URL=http://localhost:3000
Basic Server Setup
Create auth.ts (root, lib/, utils/, or under src/app/server/):
export const auth = betterAuth({ database: { // See references/database-integration.md }, emailAndPassword: { enabled: true, autoSignIn: true }, socialProviders: { github: { clientId: process.env.GITHUB_CLIENT_ID!, clientSecret: process.env.GITHUB_CLIENT_SECRET!, } } });
Database Schema
Mount API Handler
Next.js App Router:
export const { POST, GET } = toNextJsHandler(auth);
Other frameworks: See references/email-password-auth.md#framework-setup
Client Setup
Create auth-client.ts:
export const authClient = createAuthClient({ baseURL: process.env.NEXT_PUBLIC_BETTER_AUTH_URL || "http://localhost:3000" });
Basic Usage
// Sign in await authClient.signIn.email({ email: "user@example.com", password: "secure123" });
// OAuth await authClient.signIn.social({ provider: "github" });
// Session const { data: session } = authClient.useSession(); // React/Vue/Svelte const { data: session } = await authClient.getSession(); // Vanilla JS
Feature Selection Matrix
| Feature | Plugin Required | Use Case | Reference |
|---|---|---|---|
| Email/Password | No (built-in) | Basic auth | email-password-auth.md |
| OAuth (GitHub, Google, etc.) | No (built-in) | Social login | oauth-providers.md |
| Email Verification | No (built-in) | Verify email addresses | email-password-auth.md |
| Password Reset | No (built-in) | Forgot password flow | email-password-auth.md |
| Two-Factor Auth (2FA/TOTP) | Yes (twoFactor) | Enhanced security | advanced-features.md |
| Passkeys/WebAuthn | Yes (passkey) | Passwordless auth | advanced-features.md |
| Magic Link | Yes (magicLink) | Email-based login | advanced-features.md |
| Username Auth | Yes (username) | Username login | email-password-auth.md |
| Organizations/Multi-tenant | Yes (organization) | Team/org features | advanced-features.md |
| Rate Limiting | No (built-in) | Prevent abuse | advanced-features.md |
| Session Management | No (built-in) | User sessions | advanced-features.md |
Auth Method Selection Guide
Choose Email/Password when:
- Building standard web app with traditional auth
- Need full control over user credentials
- Targeting users who prefer email-based accounts
Choose OAuth when:
- Want quick signup with minimal friction
- Users already have social accounts
- Need access to social profile data
Choose Passkeys when:
- Want passwordless experience
- Targeting modern browsers/devices
- Security is top priority
Choose Magic Link when:
- Want passwordless without WebAuthn complexity
- Targeting email-first users
- Need temporary access links
Combine Multiple Methods when:
- Want flexibility for different user preferences
- Building enterprise apps with various auth requirements
- Need progressive enhancement (start simple, add more options)
Core Architecture
Better Auth uses client-server architecture:
- Server (
better-auth): Handles auth logic, database ops, API routes - Client (
better-auth/client): Provides hooks/methods for frontend - Plugins: Extend both server/client functionality
Implementation Checklist
- Install
better-authpackage - Set environment variables (SECRET, URL)
- Create auth server instance with database config
- Run schema migration (
npx @better-auth/cli generate) - Mount API handler in framework
- Create client instance
- Implement sign-up/sign-in UI
- Add session management to components
- Set up protected routes/middleware
- Add plugins as needed (regenerate schema after)
- Test complete auth flow
- Configure email sending (verification/reset)
- Enable rate limiting for production
- Set up error handling
Reference Documentation
Core Authentication
- Email/Password Authentication - Email/password setup, verification, password reset, username auth
- OAuth Providers - Social login setup, provider configuration, token management
- Database Integration - Database adapters, schema setup, migrations
Advanced Features
- Advanced Features - 2FA/MFA, passkeys, magic links, organizations, rate limiting, session management
Scripts
scripts/better_auth_init.py- Initialize Better Auth configuration with interactive setup
Resources
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