Next.js 16 + Better Auth + Drizzle Template

A modern, production-ready Next.js 16 starter template featuring robust authentication, database management, and optimized route organization.

🚀 Features

• Next.js 16 (App Router): Utilizing the latest React 19 features and Turbopack.
• Better Auth: Comprehensive authentication system with session management.
• Automated Migrations: Database migrations are automatically applied on application launch.
• Drizzle ORM: Type-safe database interactions with PostgreSQL.
• Route Groups & Security Proxy:
  • (authenticated): Private routes protected by a server-side layout proxy.
  • (guest): Public-only routes (Login/Register) with auto-redirect for logged-in users.
• Path Aliases: Standardized @/* imports for clean and reliable module resolution.
• Biome: Ultra-fast linting and formatting.
• Tailwind CSS 4: Modern styling with native CSS variable support.

📁 Project Structure

├── app/
│   ├── (authenticated)/  # Protected routes (requires login)
│   │   ├── layout.tsx    # Security Proxy & Permission check
│   │   └── page.tsx      # Dashboard / Home
│   ├── (guest)/          # Public routes (login, register)
│   │   ├── layout.tsx    # Guest-only redirect logic
│   │   ├── login/
│   │   └── register/
│   ├── api/auth/         # Better Auth API handlers
│   └── layout.tsx        # Root layout
├── components/           # UI Components (shadcn/ui)
├── lib/
│   ├── db/               # Drizzle schema and client
│   ├── auth.ts           # Server-side Auth config
│   └── auth-client.ts    # Client-side Auth hook
└── drizzle/              # Generated migrations

🛠️ Getting Started

1. Environment Setup

Copy .env.example to .env.local and fill in your credentials:

cp .env.example .env.local

2. Database

Start the local database using Docker:

bun db:up

Generate migrations after making changes to your schema:

bun db:generate

Note: Migrations are automatically applied when the application starts (via instrumentation.ts). You can also run them manually using bun db:migrate.

3. Development

Install dependencies and run the server:

bun install
bun dev

Open http://localhost:3000 to see your app.

📜 Available Scripts

• bun dev: Start development server with Turbopack.
• bun lint:fix: Run Biome to fix linting and formatting.
• bun db:generate: Generate migration files from your schema.
• bun db:migrate: Manually apply migrations to the database.
• bun db:studio: Open Drizzle Studio to explore your data.

🔒 Security & Permissions

The app/(authenticated)/layout.tsx file acts as a centralized security proxy. It checks for a valid session before rendering any children.

A commented-out placeholder is available in the layout to implement role-based access control (RBAC):

// const userRole = session.user.role;
// if (!allowedRoles.includes(userRole)) redirect('/dashboard?error=denied');