oauth21-token-endpoint

To implement an OAuth 2.1 token endpoint with PKCE verification, you must enforce POST-only, form-encoded requests over HTTPS, verify the PKCE code challenge against the stored verifier, and return compliant token responses with no-store caching headers.

An OAuth 2.1 token endpoint needs to support authorization_code, refresh_token, and client_credentials grant types, each requiring proper client authentication, specific request validation, and correctly formatted token response issuance.

CORS support for an OAuth 2.1 token endpoint involves configuring cross-origin headers to allow browser-based clients to securely POST form-encoded token requests while maintaining TLS enforcement and strict error handling.

A compliant OAuth 2.1 token response requires Cache-Control no-store headers to prevent caching, must be transmitted exclusively over HTTPS with TLS enforcement, and formatted correctly per the standard.

An OAuth 2.1 token endpoint requires POST-only form-encoded requests to securely transmit client credentials and authorization codes, preventing sensitive data from being exposed in URL query parameters or cached logs.

The client_credentials grant type on an OAuth 2.1 token endpoint focuses on machine-to-machine client authentication and does not utilize PKCE verification, which is specifically enforced for authorization_code grant requests.