Authentication

Authentication Mastery (Better Auth)

Framework-agnostic TypeScript authentication with Better Auth. Supports email/password, social OAuth, 2FA, passkeys, and enterprise features.

Auth Method Selection

Quick Start

npm install better-auth

BETTER_AUTH_SECRET=<generated-secret-32-chars-min>
BETTER_AUTH_URL=http://localhost:3000

Server Setup

// lib/auth.ts
import { betterAuth } from "better-auth"

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!,
    },
    google: {
      clientId: process.env.GOOGLE_CLIENT_ID!,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET!,
    }
  }
})

Client Setup

// lib/auth-client.ts
import { createAuthClient } from "authentication/client"

export const authClient = createAuthClient({
  baseURL: process.env.NEXT_PUBLIC_BETTER_AUTH_URL || "http://localhost:3000"
})

Mount API (Next.js)

// app/api/auth/[...all]/route.ts
import { auth } from "@/lib/auth"
import { toNextJsHandler } from "authentication/next-js"
export const { POST, GET } = toNextJsHandler(auth)

Basic Usage

// Sign up
await authClient.signUp.email({ email, password, name })

// Sign in
await authClient.signIn.email({ email, password })
await authClient.signIn.social({ provider: "github" })

// Session (React hook)
const { data: session } = authClient.useSession()

// Protected route
if (!session) redirect('/login')

Reference Navigation

• Email/Password Auth — Setup, verification, password reset, username auth
• OAuth Providers — Social login, provider config, token management
• Advanced Features — 2FA, passkeys, magic links, organizations, RBAC
• Database Integration — Adapters, schema, migrations for PostgreSQL/MongoDB
• Security Best Practices — Rate limiting, session management, CSRF, secure cookies

Implementation Checklist

• Install better-auth, set env vars
• Create auth server with database config
• Run npx @authentication/cli generate for schema
• Mount API handler in framework
• Create client instance
• Build sign-up/sign-in UI
• Add session management
• Set up protected routes/middleware
• Configure email sending (verification/reset)
• Enable rate limiting for production
• Add plugins as needed (regenerate schema after)

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