Authentication.md

Authentication in SaaS

Choosing the right auth provider is critical for security and user experience.

Top Recommendations

1. Clerk (Recommended)

Clerk is the easiest way to add authentication and user management to your Next.js application. It handles everything from login/signup to organization switching.

Setup:

npm install @clerk/nextjs

Features:

• Pre-built UI components (<SignIn />, <UserProfile />)
• Multi-tenancy (Organizations) support out of the box.
• Webhooks for syncing with your database.

2. NextAuth.js (Auth.js)

The open-source standard for Next.js. Best if you want full control over your data and sessions.

Setup:

npm install next-auth

Strategy: Use the Prisma Adapter to store users directly in your database.

// pages/api/auth/[...nextauth].js
import NextAuth from "next-auth"
import { PrismaAdapter } from "@next-auth/prisma-adapter"
import { PrismaClient } from "@prisma/client"

const prisma = new PrismaClient()

export default NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    // GitHub, Google, etc.
  ],
})

Auth Checklist

• Social Login (Google/GitHub)
• Email/Password with MFA
• Magic Links (Passwordless)
• Session Management
• RBAC (Role Based Access Control)