Authentication Patterns — Complete Implementation Guide

Authentication Patterns — Complete Guide Overview

Authentication patterns verify user identity through sessions, tokens, OAuth, SAML, or biometrics before granting access to protected API resources.

Session-Based Authentication — Complete Server-Side Guide

Session-based authentication stores user sessions server-side with a cookie identifier, providing immediate revocation and simple implementation for web applications.

Token-Based Authentication — Complete Stateless Auth Guide

Token-based authentication uses signed tokens to prove identity without server-side session storage, enabling stateless, scalable API authentication.

JWT Authentication — Complete JSON Web Token Guide

JWT authentication uses signed JSON tokens containing claims about the user, enabling stateless, self-contained identity verification across distributed systems.

JWT Access and Refresh Tokens — Complete Session Management Guide

JWT access and refresh token pattern combines short-lived access tokens with long-lived refresh tokens for secure, seamless API authentication.

OAuth 2.0 Authorization Code Flow — Complete Delegated Auth Guide

OAuth 2.0 authorization code flow delegates user authentication to a provider, issuing tokens to third-party apps without exposing user credentials.

OAuth 2.0 Client Credentials — Complete Server-to-Server Auth Guide

OAuth 2.0 client credentials flow enables secure server-to-server authentication where applications authenticate using their own identity without user context.

OAuth 2.0 PKCE — Complete Mobile and SPA Auth Guide

OAuth 2.0 PKCE extends authorization code flow with a dynamically generated secret, preventing authorization code interception attacks on mobile and SPA clients.

OpenID Connect — Complete Identity Authentication Guide

OpenID Connect adds user authentication to OAuth 2.0 with ID tokens containing verified identity claims, enabling single sign-on across applications.

SAML Authentication — Complete Enterprise SSO Guide

SAML authentication enables enterprise single sign-on by exchanging XML-based assertions between identity providers and service providers for federated identity management.

API Keys — Complete Service Authentication Guide

API keys authenticate services and applications using unique identifiers passed in request headers, enabling simple, scalable machine-to-machine authentication.

HTTP Basic Authentication — Complete API Auth Guide

HTTP Basic Authentication sends username and password in each request header, providing simple API authentication that must be paired with HTTPS encryption.

Multi-Factor Authentication — Complete MFA Implementation Guide

Multi-factor authentication adds a second verification layer beyond passwords, requiring something you know plus something you have or are to access your API.

Passwordless Authentication — Complete No-Password Login Guide

Passwordless authentication uses magic links, one-time codes, or biometrics instead of passwords, reducing phishing risk and improving user experience.

Social Login — Complete OAuth Social Authentication Guide

Social login lets users authenticate with existing accounts from Google, GitHub, Facebook, or Apple using OAuth 2.0 and OpenID Connect protocols.

LDAP Integration — Complete Directory Authentication Guide

LDAP integration authenticates users against enterprise directories like Active Directory, enabling centralized user management for corporate API access.

Token Storage — Complete Secure Client-Side Storage Guide

Token storage strategies determine how access and refresh tokens are stored client-side, balancing security against XSS and CSRF attack risks.

Auth Middleware — Complete Authentication Enforcement Guide

Auth middleware centralizes token validation, user lookup, and permission checks across all API endpoints, preventing authentication gaps and code duplication.

CSRF Protection — Complete Anti-Forgery Patterns Guide

CSRF protection in authentication patterns prevents attackers from using authenticated sessions to perform unauthorized actions through hidden requests.

Authentication Project — Complete Multi-Strategy Auth Implementation

Apply all authentication patterns by building a production-grade API supporting JWT, OAuth 2.0, social login, MFA, and API keys simultaneously.