This is the working repository for ‘The API’ book written by Sergey Konstantinov (email, Linkedin profile, Medium blog).

API-first development is one of the hottest technical topics nowadays since many companies started to realize that API serves as a multiplicator to their opportunities—but it also amplifies the design mistakes as well.

This book is written to share the expertise and describe the best practices in designing and developing APIs. It comprises six sections dedicated to:

• The API design
• API patterns
• backwards compatibility
• HTTP API & REST
• SDK and UI libraries
• API product management.

This is an open-source book distributed under the Creative Commons Attribution-NonCommercial 4.0 International license.

The second edition of the book is finished! This is everything I ever wanted to tell the reader.

There are several areas to improve:

• Add more diagrams
• Add more live code examples (specifically — SearchBox designed in MVP paradigm and using React/Redux).

I am accepting inquiries. Feel free to open issues.

I am NOT accepting pull requests introducing any new content, since I'm willing to be the only author. I would gratefully accept typo fixes, though.

Thanks art.mari.ka for the illustration & inspiration.

Thanks Ilya Subbotin and Fedor Golubev for the valuable feedback.

Thanks Ira Gorelik for the Aqueduct.

Thanks Friedrich Althausen for Vollkorn, Christian Robertson for Roboto Mono, and ParaType for PT Sans.

Thanks Knut Sveidqvist and Mermaid Comminuty for Mermaid.

Thanks Figma, Inc. for Figma and Joey Banks for UI Kit.

Thanks @lual for the coffee icon.

Thanks Oscar Hinrichs for the map.