Testing OAuth Authorization and Authentication in Postman

Securing APIs is critical, but testing authorization and authentication flows can often feel complex and overwhelming. Understanding how tokens, grants, and signatures interact is essential for any developer or QA engineer working with modern web services. This text-based course guides you through the process of configuring and testing OAuth 1.0 and OAuth 2.0 flows using Postman. You will transition from understanding basic authentication concepts to confidently validating secure endpoints, managing JSON Web Tokens (JWTs), and implementing modern security standards like PKCE. What you'll learn: - Understand the core differences between authentication and authorization, including token-based structures like JWT. - Configure various OAuth 2.0 authorization flows, including Authorization Code, Client Credentials, and modern PKCE patterns. - Test secure connections to real-world APIs from platforms such as Dropbox and Flickr using Postman's built-in tools. - Write automated test scripts in Postman to validate token generation, expiration, and error handling. - Debug failed authentication requests by analyzing headers, payloads, and response codes. You will start with the fundamental definitions of identity protocols before moving into step-by-step written tutorials on configuring Postman environments, executing authorization flows, and writing assertion scripts to automate your security testing. This course is designed for beginner QA engineers, developers, and API testers who want to understand OAuth security without needing prior security testing experience. Start reading today to build a strong foundation in modern API security testing.