Topic Cluster

HTTP Authentication

Auth flows, authorization semantics, credentials handling, and access control patterns.

HTTP 401 Unauthorized: Authentication Required

Learn what 401 Unauthorized means, why it happens, and how to fix authentication errors. Complete guide with examples for APIs and web applications.

HTTP Status Codes

HTTP 403 Forbidden: Access Denied

Learn what 403 Forbidden means, why access is denied, and how to fix permission errors. Complete guide with examples for APIs and web applications.

HTTP Headers

Authentication-Info Header

Learn how Authentication-Info provides additional authentication data in responses to successful requests. Covers digest authentication and session info.

HTTP Headers

Authorization Header: HTTP Authentication

Learn how the Authorization header works, different authentication schemes (Bearer, Basic, API keys), and security best practices.

HTTP Headers

Cookie Header

Learn how the Cookie header sends stored cookies to servers with each request. Understand cookie transmission, session management, and security considerations.

HTTP Headers

Proxy-Authenticate Header

Learn how the Proxy-Authenticate header challenges clients for credentials when accessing resources through a proxy. Understand proxy authentication schemes.

HTTP Headers

Proxy-Authorization Header

Learn how Proxy-Authorization provides credentials to access resources through a proxy server. Understand proxy authentication schemes and security.

HTTP Headers

Set-Cookie

Learn how the Set-Cookie header instructs browsers to store cookies with attributes like HttpOnly, Secure, SameSite, and expiration settings.

HTTP Headers

WWW-Authenticate

Learn how the WWW-Authenticate header specifies authentication methods required to access protected resources. Understand Basic, Bearer, and Digest schemes.

Guides