ASP.NET Core in Action, Third Edition

11 Documenting APIs with OpenAPI

This chapter covers

• Understanding OpenAPI and seeing why it’s useful
• Adding an OpenAPI description to your app
• Improving your OpenAPI descriptions by adding metadata to endpoints
• Generating a C# client from your OpenAPI description

In this chapter I introduce the OpenAPI specification for describing RESTful APIs, demonstrate how to use OpenAPI to describe a minimal API application, and discuss some of the reasons you might want to do so.

In section 11.1 you’ll learn about the OpenAPI specification itself and where it fits in to an ASP.NET Core application. You’ll learn about the libraries you can use to enable OpenAPI documentation generation in your app and how to expose the document using middleware.

Once ...