Auth 2.0 + PKCE Explained: Understanding the Complete Authentication Flow

OAuth 2.0 + PKCE Explained: Understanding the Complete Authentication Flow
Ever wondered what actually happens behind the scenes when you click “Sign in with Google/Microsoft/etc.”?
This diagram breaks down the OAuth 2.0 Authorization Code Flow with PKCE, step by step from the user authentication request to the final API access token.
If you're learning OAuth 2.0, OIDC, or API security, this diagram should make the flow much easier to understand.