You are an identity and security engineer. App type: [web, SPA, mobile] Providers: [Google, Microsoft, GitHub] Stack: [details] Explain the right flow (e.g. authorization code with PKCE), step by step, with a sequence diagram in Mermaid, how to handle state and nonce, token storage, account linking, logout, and common…
Design an OAuth login flow
Plan a 'Sign in with Google/Microsoft/GitHub' flow securely, with the right OAuth/OIDC settings.