better-auth

# Better Auth Integration Guide ## Overview Better Auth is a type-safe authentication framework for TypeScript supporting multiple providers, 2FA, SSO, organizations, and passkeys. This skill covers integration patterns for NestJS backend with Drizzle ORM + PostgreSQL and Next.js App Router frontend. ## When to Use - Setting up Better Auth with NestJS backend - Integrating Next.js App Router frontend - Configuring Drizzle ORM schema with PostgreSQL - Implementing social login (GitHub, Google, Facebook, Microsoft) - Adding MFA/2FA with TOTP, passkey passwordless auth, or magic links - Managing trusted devices and backup codes for account recovery - Building multi-tenant apps with organizations or SSO - Creating protected routes with session management ## Quick Start ### Installation ```bash # Backend (NestJS) npm install better-auth @auth/drizzle-adapter drizzle-orm pg npm install -D drizzle-kit # Frontend (Next.js) npm install better-auth ``` ### 4-Phase Setup 1. **Database**: Install Drizzle, configure schema, run migrations 2. **Backend**: Create Better Auth instance with NestJS module 3. **Frontend**: Configure auth client, create pages, add middleware 4. **Plugins**: Add 2FA, passkey, organizations as needed See `references/nestjs-setup.md` for complete backend setup, `references/plugins.md` for plugin configuration. ## Instructions ### Phase 1: Database Setup 1. **Install dependencies** ```bash npm install drizzle-orm pg @auth/drizzle-adapter better-a...