Best Auth API in 2026

import { ClerkProvider, SignIn } from '@clerk/nextjs';

// middleware.ts
import { clerkMiddleware } from '@clerk/nextjs/server';
export default clerkMiddleware();

// app/sign-in/page.tsx
export default function SignInPage() {
  return <SignIn />;
}

import { auth } from 'express-openid-connect';
import express from 'express';

const app = express();

app.use(auth({
  authRequired: false,
  auth0Logout: true,
  secret: process.env.AUTH0_SECRET,
  baseURL: process.env.BASE_URL,
  clientID: process.env.AUTH0_CLIENT_ID,
  issuerBaseURL: process.env.AUTH0_ISSUER_BASE_URL,
}));

app.get('/profile', (req, res) => {
  res.send(req.oidc.isAuthenticated() ? req.oidc.user : 'Logged out');
});

import { createClient } from '@supabase/supabase-js';

const supabase = createClient(
  process.env.SUPABASE_URL!,
  process.env.SUPABASE_ANON_KEY!
);

// Sign up
const { data, error } = await supabase.auth.signUp({
  email: 'user@example.com',
  password: 'secure-password',
});

// Sign in
const { data: session } = await supabase.auth.signInWithPassword({
  email: 'user@example.com',
  password: 'secure-password',
});

import { initializeApp } from 'firebase/app';
import {
  getAuth,
  createUserWithEmailAndPassword,
  signInWithEmailAndPassword,
} from 'firebase/auth';

const app = initializeApp({
  apiKey: process.env.FIREBASE_API_KEY,
  authDomain: process.env.FIREBASE_AUTH_DOMAIN,
  projectId: process.env.FIREBASE_PROJECT_ID,
});

const auth = getAuth(app);

// Sign up
const user = await createUserWithEmailAndPassword(auth, email, password);

import { betterAuth } from 'better-auth';
import { prismaAdapter } from 'better-auth/adapters/prisma';
import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient();

export const auth = betterAuth({
  database: prismaAdapter(prisma, { provider: 'postgresql' }),
  emailAndPassword: { enabled: true },
  socialProviders: {
    github: {
      clientId: process.env.GITHUB_CLIENT_ID!,
      clientSecret: process.env.GITHUB_CLIENT_SECRET!,
    },
  },
});

// Mount: app.all('/api/auth/*', toNodeHandler(auth));