Understanding and Using REST APIs: A Complete Guide

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There are various application programming interfaces (APIs). They make developers’ jobs easier, but few coders make an effort to learn more about these interfaces. Why so?

It often comes down to how busy teams of developers are, which results in time constraints and prioritization – learning more about what defines REST APIs sometimes doesn’t make the cut and may not be relevant to everyone. However, there’s a reason to know about it. Fully understanding an API is beneficial if you wish to design or work with one.

This post will uncover what’s under the hood of REST APIs and how their design principles have shaped them into the powerful applications they are today.

API Overview

Here are four brief things you should know about APIs:

1. An application programming interface (API) is a set of definitions and protocols.
2. They’re needed for creating and integrating applications.
3. It’s a contract between an information supplier and an information user.
4. With its help, you outline the content that the client (the call) and the producer (the response) should provide.

Let’s take a weather service as an example. The API design may require the user to provide a zip code and the producer to respond with a two-part response, the first of which is the highest temperature and the second is the lowest temperature.

This way, programs can communicate with one another, say, retrieve information, or execute a function via an API. An API lets you convey the request to the system to comprehend it and respond. It’s agents between users (clients) and the resources (servers) they want to access.

Suppose a user performs API requests or loads an online store. You need a quick response, so apply Magento page speed optimization techniques or the ones that work best for your CMS.

Why Do You Need an API?

1. You can use it to exchange resources and information and specify who has access to what.
2. It provides you with security, control, and authentication.
3. You don’t have to understand the software’s inner workings, such as how and where the resource is fetched. It enables services to communicate in a standard way, even if they employ various technologies.

REST API Overview

Being RESTful relates to a software architecture approach known as “Representational State Transfer”. Its most typical application is to standardize and universalize the use of web services.

These web services provide textual representations of their web resources to be read and processed via a stateless protocol. A client can do the standardized and well-known operations, which are based on HTTP protocols, such as:

• fetch;
• edit;
• delete.

What is the Process Like?

REST perceives data, such as an image, video, or text, as a resource. A client accesses a specific URL, sends a request to complete the necessary function, and gets the server response.

RESTful APIs and software don’t rely on any technology or programming breakthroughs. First introduced in 2000, REST is based on the idea of imposing specific constraints on an API to improve performance, scalability, and simplicity.

Distinguishing Characteristics of the Restful Architectural Style

Some APIs, such as SOAP or XML-RPC, impose a rigid structure on developers. On the other hand, REST APIs can be written in almost any programming language and support a wide range of data formats.

They should adhere to the six REST design principles (also known as architectural constraints) listed below:

1. Uniform Interface

This principle requires all API requests to be the same for the same resource regardless of the request origin.

The REST API should ensure that the same data, such as a user’s name or email address, is associated with only one uniform resource identification (URI).

Resources should contain all of the needed information while not being excessively huge.

2. Separating the Client and the Server

REST API design requires client and server apps to be independent. The only available information to the client application is the URI of the requested resource. There’s no other way to communicate with the server application.

The same happens to a server application. It shouldn’t change the client program other than providing the required data over HTTP.

3. Stateless Client-Server Communication

Because REST APIs are stateless, each request should include all the data needed to process it. It means there is no need for server-side sessions.

Server applications shouldn’t store any data associated with a client request, so the session state must be kept solely by the client application.

4. Cacheable Data

Client-side or server-side caching of resources should be used wherever possible. If caching is permitted for the provided resource, server responses should include that information. On the client-side, the goal is to increase performance while boosting server scalability.

5. Layered System Architecture

RESTful architecture mandates a layered design structure. Such layers work as intermediaries to ensure the API is simple to comprehend and scale. A defined architecture while executing a command means that each layer performs a role before passing the data to the next.

The connected layers ensure that the client and server apps don’t interact directly. They communicate with one another instead of every other program component, enhancing the API’s overall security.

What can you do with the layers? If the API’s scope changes, you can add, update, or remove them without affecting other interface components.

6. Code on Demand (Optional)

REST APIs typically deliver static resources. However, REST provides extended client functionality by downloading and running code in applets or scripts. The code should only run on-demand in these situations.

This benefits the client as the downloaded code reduces the number of pre-implemented features required. All the client needs to do is execute the code that servers transmit.

To Conclude

APIs are essential for delivering data, capabilities, and services and improving customer experience. But the API design has moved to more lightweight and flexible versions that are suited to mobile apps and geo-distributed networks. And that’s where REST APIs can help.

They’re ideal for mobile apps, social networking sites, and various other applications. Businesses rely on REST APIs to generate revenue and expand their services.

REST API adoption will continue to be one of the most cost-effective ways to support the next generation of business apps. Once you’ve understood how to use it, you can develop the next big thing.

Need more help? Check out the Zentao blog. They have more articles on project management tools, software management, building cross-functional teams, and so much more.

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Author bio :

Alex Husar, chief technology officer at Onilab with 8+ years of experience in developing PWAs, Magento migration, and Salesforce development. He graduated from the Czech Technical University and obtained a bachelor’s degree in Computer Software Engineering. Alex’s expertise includes both full-stack dev skills and a strong ability to provide project-critical guidance to the whole team.