REST APIs are a critical part of coding infrastructure designed to easily integrate applications. 

But what exactly are REST APIs, and how do they work?

In the past, we’ve thoroughly discussed what APIs are and the various types of API calls that exist. But as a reminder, an API (application programming interface) is a series of rules that guides communication between applications and devices. The API takes a request from a user, communicates with the server, and then delivers the response to that request.

A REST API is an API that features representational state transfer design. This format provides greater flexibility for developers.

The Characteristics of REST Design

There are six primary design principles associated with REST APIs.They are as follows:

• Uniform interface: Any API requests for the same resource must always look the same, regardless of the source of the request. Resources should always contain all information the client would need when making the request without being too large.
• Client-server decoupling: Client and server applications in REST design must always be independent of each other. The client application cannot interact with the server application, and the server application cannot modify the client application in any way.
• Statelessness: Each request must include all information needed to process it. No server-side sessions are required. Server applications cannot store any data related to requests from clients.
• Cacheability: Resources should be cacheable on either side (client or server) as a means of improving performance for the client and scalability for the server. Any server response must include information about whether caching of the delivered resource is allowed.
• Layered system architecture: Calls and responses in REST APIs go through multiple layers, which means the client and server might not connect directly. Neither client nor server should be able to determine whether it is communicating with the end application or some form of intermediary.
• Code on demand: In some cases, responses to API calls may contain executable code, in which case they should only run on demand.

How Do REST APIs Work?

REST APIs take in requests for a resource (any type of data or information) and then send back all relevant information about that resource in a clear, simple format for the person or program using the API (the client).

REST APIs are used all over the internet. Any internet user will almost certainly have encountered one at some point, whether they know it or not.

Here are a few examples of REST APIs and how they operate when implemented.

• YouTube: YouTube’s REST API can deliver information about specific videos, returning information such as a video name, date of publication, view count, link or account. Using the YouTube REST API, a user could also post videos to a personal YouTube channel or add videos to a playlist.
• Twitter: Twitter has its own API that allows third-party applications to read and write data. It can be implemented to write, post or share tweets and read profiles, as well as downloading and analyzing large amounts of tweets grouped by subject.
• Spotify: Spotify has a web API that enables requests for information about songs, artists, albums and playlists. It can also be used for adding songs to playlists, playing music, and shuffling songs, among other features.

The Benefits of Using REST APIs

There are several main benefits to the use of REST APIs in programming:

• Flexibility: This is far and away the biggest benefit associated with using REST APIs. These tools are highly flexible, capable of handling a wide range of requests and delivering data back to users in many formats. Creative programmers can employ REST APIs for just about any purpose to deliver a better user experience.
• Simplicity: Because REST APIs incorporate web technologies that are already implemented, they are simple to create and use. 
• Scalability: The combination of simplicity and flexibility makes REST APIs highly scalable. These APIs can be used to communicate between any software, regardless of the sizes or capabilities of those pieces of software. Even as an application grows and collects more data, the REST API will be able to still process requests quickly and accurately.

Using Boomi for REST API Management

Boomi API Management assists developers throughout the entire lifecycle of an API for development, implementation, management, and security. We make API management as simple as possible for applications of all types.

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