Best API Architecture Practices: Server or Client API Calls?

Applications Programming Interface dictates how applications communicate. See the best API architecture practices for server or client calls.

Best API Architecture Practices: Server or Client API calls

What is an API?

An API (Applications Programming Interface) is a software interface that dictates how different applications communicate and share data. Every time you are using an application such as Uber, sending messages on Twitter, or even checking the weather on your smartphone, you are using an API. APIs allow these applications to communicate through calls. They (APIs) dictate the calls that are made, the responses received, and the conventions and data formats used. In this article, we’ll see the best API architecture practices for server or client API calls.

What is Client-Server Architecture?

Most of the applications we use today are based on this model. Here, user devices use a network of centrally located servers to communicate and get all the information that they need. This means that they do not communicate with each other directly but through the server.

In this model, user devices – smartphones, laptops, and other smart devices – are referred to as clients. When a user is accessing an application using these devices, they send requests to the servers to get the information that they need. In return, the server responds with what the applications need. 

There are developers that implement a server-only or client-only architecture when building their APIs. These two work differently, and it is important for all developers to understand the differences between the client-side and server-side.

The Client-Only API Architecture

When designing an API architecture, some developers might find themselves in a situation where they are not sure of which architecture to implement. Some of them go for the client-only architecture. But how does this architecture work?

The client-side is used to refer to everything that the end-user can see such as images, text, and the entire user interface, and every action performed by an application on the user devices. So, one of the top API architecture practices.

For instance, the client-side uses the browser to interpret markup languages such as CSS and HTML. This has forced many developers to implement processes on the client-side and move away from having everything done on the server side.

A good example of client-side processes can be seen when one visits The homepage consists of the videos recommended by YouTube, based on different aspects such as the videos one watches. Here, the browser interprets the JavaScript, CSS, and HTML dictating the appearance of the main YouTube page. This happens on the client-side. 

YouTube: API Architecture Practices

The YouTube page responds to events as well. For example, hovering the mouse cursor over the video thumbnails shows a preview of the video, as well as menu items to add the video to the queue or to watch it later. This is a good example of processes taking place on the client side. These processes are by the code on the webpage without any communication to the server.

When implementing a client-only API architecture, developers need to keep the following options in mind;

  • The client-side architecture allows applications to update and load content without having to reload entire pages. This can be in web applications that implement features such as live chats that need to be active even when the user is opening other pages.
  • Modern browsers come with local storage features that allow developers to cache code generated on the client-side.
  • Developers need to make sure that they have provided workarounds specific to different browsers. This is because the client does all the rendering required.
  • Implementing the client-side architecture means that developers need to catch any errors that might occur and send them to the server. This, when not carefully thought about, can bring issues with error handling.

The Server-Only API Architecture

The server-side is to refer to all the processes that take place on the server. A while back, almost all processes including those discussed above took place on the server. This has so far changed.

The major issue with having all the processes running on the server is that when there is a request to perform any of them, the request has to travel to the server from the client. This process has to repeat for every single request made by the client. This leads to latency.

When implementing a server only API architecture, developers need to consider a number of things, among them; 

  • Most of the rendering is on the server-side. This means that developers rarely depend on JavaScript on the client side, and therefore, they will deal with reduced issues from the client.
  • In case of errors, developers can easily identify and handle them since they are on the server.
  • In case there are issues with content generation, developers can minimize server load by caching such content.
  • Content has to be refreshed as users navigate through an application. Even though this is not wrong, it can bring issues, especially for large projects. 

Depending on the type of your APIs’ business model, you need to make sure that you are choosing the right architecture that meets your requirements. Both these architectures are good, but it depends on the functionalities and operations of your APIs. The right architecture will dictate the success of your APIs.