better-auth

npm install better-auth

// lib/auth.ts — Better Auth server setup
import { betterAuth } from 'better-auth'
import { prismaAdapter } from 'better-auth/adapters/prisma'
import { prisma } from './db'

export const auth = betterAuth({
  database: prismaAdapter(prisma, { provider: 'postgresql' }),

  emailAndPassword: {
    enabled: true,
    minPasswordLength: 8,
  },

  socialProviders: {
    google: {
      clientId: process.env.GOOGLE_CLIENT_ID!,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET!,
    },
    github: {
      clientId: process.env.GITHUB_CLIENT_ID!,
      clientSecret: process.env.GITHUB_CLIENT_SECRET!,
    },
  },

  session: {
    expiresIn: 60 * 60 * 24 * 7,        // 7 days
    updateAge: 60 * 60 * 24,              // refresh every 24h
  },

  // Plugins for additional features
  plugins: [],
})

// app/api/auth/[...all]/route.ts — Next.js API handler
import { auth } from '@/lib/auth'
import { toNextJsHandler } from 'better-auth/next-js'

export const { GET, POST } = toNextJsHandler(auth)

// lib/auth-client.ts — Client-side auth
import { createAuthClient } from 'better-auth/react'

export const authClient = createAuthClient({
  baseURL: process.env.NEXT_PUBLIC_APP_URL,
})

// React hooks
export const { useSession, signIn, signUp, signOut } = authClient

// components/LoginForm.tsx — Login with email or OAuth
import { signIn } from '@/lib/auth-client'

export function LoginForm() {
  return (
    <div>
      <form onSubmit={async (e) => {
        e.preventDefault()
        const form = new FormData(e.currentTarget)
        await signIn.email({
          email: form.get('email') as string,
          password: form.get('password') as string,
        })
      }}>
        <input name="email" type="email" required />
        <input name="password" type="password" required />
        <button type="submit">Sign In</button>
      </form>

      <button onClick={() => signIn.social({ provider: 'google' })}>
        Continue with Google
      </button>
      <button onClick={() => signIn.social({ provider: 'github' })}>
        Continue with GitHub
      </button>
    </div>
  )
}

// middleware.ts — Next.js route protection
import { auth } from '@/lib/auth'
import { headers } from 'next/headers'

export async function getSession() {
  const session = await auth.api.getSession({
    headers: await headers(),
  })
  return session
}

// In a server component or page
const session = await getSession()
if (!session) redirect('/login')