Azure Auth - Microsoft Entra ID for React + Cloudflare Workers

Package Versions: @azure/msal-react@5.0.2, @azure/msal-browser@5.0.2, jose@6.1.3 Breaking Changes: MSAL v4→v5 migration (January 2026), Azure AD B2C sunset (May 2025 - new signups blocked, existing until 2030), ADAL retirement (Sept 2025 - complete) Last Updated: 2026-01-21

Architecture Overview

┌─────────────────────┐     ┌──────────────────────┐     ┌─────────────────────┐
│   React SPA         │────▶│  Microsoft Entra ID  │────▶│  Cloudflare Worker  │
│   @azure/msal-react │     │  (login.microsoft)   │     │  jose JWT validation│
└─────────────────────┘     └──────────────────────┘     └─────────────────────┘
        │                                                          │
        │  Authorization Code + PKCE                               │
        │  (access_token, id_token)                                │
        └──────────────────────────────────────────────────────────┘