🔗 What's OAuth2 Anyway?

Have you ever logged into a website using your Google or Facebook account? Or connected an app to access your GitHub data? If so, you’ve already used OAuth2, whether you knew it or not.

OAuth2 is the world’s most popular, extensible authorization framework. It allows you to integrate a couple of systems together by delegating access to your data from one service to another. But here is the thing - most people don’t really understand how OAuth2 really works.

Personally, I’ve implemented several applications that were using OAuth2. The process was so straightforward that I had no need to stop and think about the protocol itself along the way. That’s by design. OAuth2 is built to be super simple to implement client applications, not to wrestle with complex authentication requirements.

But if we pause and dig deeper, there’s a lot to learn from the software engineering point of view.

In this article, we will uncover the “whys” behind the OAuth2 protocol design and break down the most common authentication grants.