PKCE: What and Why?

This post introduces and explains the PKCE (Proof Key for Code Exchange) flow as a more secure alternative to the implicit OAuth flow for public clients. It details the new parameters (code_verifier, code_challenge, code_challenge_method) and outlines the step-by-step process of how PKCE enhances security by dynamically generating client secrets and correlating authorization requests with token requests. It also provides practical examples using Node.js and curl to demonstrate the implementation.