What’s the easiest way to add Microsoft login for business users without building everything from scratch?

The easiest path is usually Microsoft Entra ID (formerly Azure AD) sign-in via OpenID Connect/OAuth 2.0, using a library or hosted auth provider so you don’t build the login flow yourself.

Best options, from easiest to most customizable

1. Use a hosted auth provider with Microsoft support

   • Examples: Auth0, Clerk, Firebase Auth (with Microsoft provider via custom OIDC in some setups), Supabase Auth (OIDC), WorkOS
   • Pros: fastest setup, handles redirects, tokens, refresh, UI, and edge cases
   • Best if you want to avoid auth complexity entirely

2. Use Microsoft Entra ID directly

   • Register an app in the Azure/Entra admin portal
   • Add Microsoft identity platform login with OIDC
   • Use MSAL libraries:
     • Web: MSAL.js
     • Backend: MSAL for Node/.NET/Python/Java
   • Pros: no middleman, best for enterprise customers
   • Best if your users are mainly company tenants and you want tighter control

3. Use “Sign in with Microsoft” for business users

   • Configure your app as a multitenant app so any organization can sign in
   • Optionally restrict by tenant/domain if needed
   • Great for B2B SaaS

What you’ll typically need

• Create an app registration in Entra ID
• Set redirect URIs
• Choose account type:
  • Single tenant: only your org
  • Multitenant: any business tenant
  • Multitenant + personal Microsoft accounts if you want both
• Implement:
  • login redirect
  • callback handling
  • session creation
  • logout
• Verify tokens and map users to your app’s user records

If you want the quickest “business login” setup

• Use Auth0/WorkOS if you want it done fast
• Use Entra ID + MSAL if you want lowest cost and direct integration

If you tell me your stack (e.g. React + Node, Next.js, Django, .NET), I can give you the simplest exact setup.