To proceed through this book, you will need a computer running Windows (10 or 11) and an internet connection. It is best if your computer has at least 16 GB of memory, and, of course, you’ll need room on your disk for the software and for the code you will write.

You can create APIs on any platform (e.g., Linux) and use any development environment (e.g., Visual Studio Code instead of Visual Studio). This book, however, will focus on Visual Studio and Windows as they are the most popular and arguably the most powerful way to create .NET APIs.

The code files for this book are available in the book’s GitHub repository: https://github.com/PacktPublishing/Programming-APIs-with-C-Sharp-and-.NET.

When you are creating a decoupled application, your principal parts are:

• The front end
• The back end
• The middleware

A typical front end might be a web application, a mobile application, or other ways of displaying data.

A typical backend might be a database or another service.

The middleware sits between the front end and the back end. The most important middleware is the API. The job of the API is to ensure that the front end and back end are decoupled – that is, you can modify one without affecting the other. This is simply good programming practice and will save you hours (or months) of rewriting should either of these change (which they will!).

Typically, the backend and the frontend are created by different teams, though, of course, you can have one developer creating it all. We’re also going to restrict our backend to a simple database, though any source of data can be a backend. Finally, we’re not going to build a full frontend (that would be a distraction from the point of this book) but, rather, we’re going to use a tool, Postman, to mimic a frontend. There will be more on Postman throughout this book.

You can create your backend, API, and frontend on any operating system you like. For this book, we’ll be creating all three on Windows, using Visual Studio 2022, the latest Postman, and Dapper as a simple Object Relational Mapper (ORM) to make our lives easier. There are a few other simple tools we’ll be using, so let’s get you set up.

Downloading the free software you need

To get started, if you don’t have Visual Studio installed, go to https://visualstudio.com and click on Downloads (this site changes frequently but the basic steps remain the same). You have three choices of which version to download: Community, Professional, and Enterprise. The Community version is free and will provide all you need to follow along in this book.

When you click on your choice, Visual Studio Setup will download to your downloads directory. Double-click on it and click on Yes at the security prompt. The installer will update itself and then will begin the installation. This can take a little while, but don’t go away as you have some selections to make.

Note

If you have Visual Studio installed but for some reason want to install the Community Edition as well, that is no problem as they can run side by side.

A menu will appear similar to Figure 1.1 (if it does not, click Modify).

Figure 1.1 – Setting up Visual Studio: please note that this screenshot intends to show the layout, so text readability is not essential

Be sure that ASP.NET and web development is checked. Scroll down and check Data storage and processing (if you are short on disk space, skip this one). Once you are satisfied, click on Install while downloading and then click on Modify.

SQL Server will be installed for you, as will SQL Server Management Studio (SSMS). You will typically interact with SQL Server through SSMS. We will look at how to work with this tool, and all the others, as we go.

Your next tool is Dapper. This is a small, lightweight ORM (often called a micro-ORM) that does one important part of the work of the much bigger SQL platform, Entity Framework, but with much less overhead. Specifically, Dapper will map queries to objects.

Since our needs will be minimal, Dapper will be more than enough. You can read more about Dapper here: https://www.learndapper.com/.

We will mimic our user interface with Postman, which we will also use for end-to-end testing. You can get the latest version of Postman at https://postman.com/downloads. You can also access Postman through your browser, but we’ll be using the downloaded version.

Postman is surprisingly powerful, and we will review how we will use it as we go along. That said, we will only scratch the surface of what you can do with this tool, so at some point, you may want to read the documentation.

We will be using Swagger for documentation (see Chapter 4), and the built-in logger functionality for (surprise!) logging errors and issues that will not be surfaced to the user, but which will be useful for you as the programmer.

In this chapter, you saw what software you will need, how to download it, and how to install it. All of the software we’ll be using in this book is free. In the next chapter, we will see the example application that we’ll build to illustrate a meaningful use of an API.

Be sure to download and install all of the software described if you want to follow along as we create the API.