OAuth 2.0 and OpenID Connect: The Professional Guide

The final release of the ebook OAuth 2.0 and OpenID Connect: The Professional Guide has been published. Get your free copy here!

Born from the initiative of one of the most influential personalities in the world of Identity, the late Vittorio Bertocci, the book analyzes OAuth 2.0 and OpenID Connect, explaining not only how they work but also the motivations that led to the creation of these standards as they are today.

The Origins of the Project

I met Vittorio when I joined Auth0 in 2019. I only knew him as an authoritative expert in the field of Identity, and I knew very little about that topic. Usually, he was in charge of onboarding training for the technical staff, but when I went to Bellevue for my onboarding, another trainer was assigned. However, he came to the office to greet me because he had learned an Italian was in the group of new hires. A clear signal that he was more than just an Identity expert: he was a person full of empathy.

I had the honor of working closely with Vittorio at the beginning of my career at Auth0. Partly for helping him with this book and partly for his review of other developer content my team and I created. This gave me the opportunity to learn a lot, not only about the technical aspects of Identity but also about how to explain complex concepts based on the specific audience. His style, which is rich in metaphors and anecdotes (you will find several in this book), has always fascinated me. His histrionic manner, his marked accent, and his all-Italian gestures establish him in my imagination as a great storyteller.

We started this book project at the end of 2019 and have published it incrementally in two editions. Vittorio had already drawn up the roadmap for the book and shared diagrams and notes with me, but his innumerable commitments led him to postpone its completion.

Vittorio's Premature Passing

His untimely death in October 2023 shocked me, as well as the entire community of Identity professionals. Several times, I received requests for information from developers about the book's completion. Therefore, I thought it was right not to disappoint readers and honor Vittorio's memory by completing the book according to the original roadmap and based on his notes. I tried as much as possible to maintain his style, even if it was unique and unrepeatable. Since this project started, some things have changed, so I had to update some references, even in the already published chapters. In this work of adaptation, updating, and revision, the help of Aaron Parecki and Filip Skokan was invaluable, and my heartfelt thanks go to them.

A Final Note on the Book

One last note before leaving you to read the book. This is not a technical handbook about OAuth 2.0 and OpenID Connect. This book will not give you detailed guidelines on how to use OAuth 2.0 and OpenID Connect in your applications. Or rather, you will learn this too, but more than anything else, this guide will explain to you the reason for the small details of these protocols, why we arrived at them, and how we arrived at them.

Understanding the reason for the technical choices and, therefore, the history behind them will help you better understand OAuth 2.0 and OpenID Connect and gain professional knowledge of them. That said, I hope you will enjoy reading this book!