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Manuel Aparicio
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REST APIs for Data Exchanges


Application Programming Interfaces (APIs) surround all-new era technology. Yet, many questions are girdling up all tech advances. From data connections to search engines and eCommerce. How can we enhance robust and worldwide systems? Largely thanks to APIs. While the term may not ring a bell, APIs are in our daily lives. Beyond phones, it applies to any device allowing users to request and receive answers. This broad field includes computers and even certain home appliances. Depending on the chosen protocol to retrieve resources, you get different APIs. Today, we'll learn more about REST APIs. Buckle up!

What is an API?

An Application Programming Interface (API) gateway grants access to an app's features and data. Further, API creation is one of the back-end dev's pillars. So, if you create an app and want it accessible to third-party apps, you'll need to create an API. To make things easier, let's explain APIs in simple terms:

Let's say you're in a restaurant. You can't (or shouldn't) walk into the kitchen and start cooking yourself. Most likely, you place your order via a server, who delivers it to the kitchen staff to prepare it. In this scenario, the kitchen staff is the backend, the menu is the database, and the waiter is the API. You choose from the menu (database), and the waiter (API) sends the info to the kitchen (back end).

The kitchen will prepare a meal and, before reaching your hands, it will go through the waiter again. In sum, an API is a ruleset specifying backend interactions. APIs allow selecting specific input from data and receiving a final-user-focused answer. 

What is a REST API?

Most APIs worldwide are Representational State Transfer (REST) APIs. This category entails a detailed set of rules to build APIs. Its architectural style is well-known for simplicity, performance, and scalability. The REST API concept rose in 2000 as part of Roy Fielding's doctorate. In his dissertation, he talked about REST in the context of the 1994 HTTP Object Model, back into HTTP 1.1. Nowadays, Fielding is an eminence in computer architecture, besides being the co-founder of the Apache HTTP Server. 

What are REST API responses?

Once you make a request, you'll get a response from a server. Yet, at this point is essential to know a couple of things. A vital concept surrounding the request's response is the status code. This three-digit number lets you know if the request was a success or a failure. The numbers can also tell if the error lies on the server, the site, or you.

Security of REST APIs

REST APIs don't have security features, yet they do support them. To generate reliability, you must enable authentication before sending any response. When dealing with sensitive information, consider using verified authentication methods.

API Keys: API keys provide identification and authorization. A key is a unique value that allows users to confirm requests. You can use these to restrict some or all the API methods, but they're not totally secure. Google offers a comprehensive guide on why and when to use API keys.

OAuth 2.0 and JSON Web Tokens: This protocol grants limited resource access while not exposing credentials. Since it requires passwords and tokens, it's a more secure method. In this field, large businesses, like Amazon, Instagram, and WordPress, use OAuth.2.0. JWTs look for secure transactions in a compact and self-contained manner. These rely on three components: a header, a payload, and a signature. 

Principles of REST APIs

You must follow some principles to design an API under REST’s architecture. 

1. Client-Server Model. The client and the server are two separate things. Here, the API acts as a connector between them. In turn, the server manages the info while the client provides input to get an output.

2. Statelessness. REST APIs must be able to process requests without relying upon other tools. Every submission needs to contain all the required info to process.

3. Layered System. APIs have a layered system. Here, clients don't know (nor have to know) how the server's structure works. This feature enhances the servers' dynamism.

4. Uniform Interface. APIs provide uniform interfaces regardless of the backend. In turn, clients can interact with them as needed. Each resource in the API should have a unique Uniform Resource Identifier.

5. Cacheable Resources. All resources returned by an API call should be cacheable. It ensures local saving on the clients' side instead of server requirements.

6. Code-On-Demand. REST APIs may include executable code, such as JavaScript, as part of a request's response. While optional, this code gives users more flexibility and customization.

REST vs SOAP API Protocols

Simple Object Access Protocol (SOAP) it's a much older service than REST. To sum it up, SOAP ensures data exchange among platforms or diverse languages. How does it compare to REST?

1. Usability. REST is more straightforward and accessible than SOAP and requires less coding. Besides, REST's way of sending data is more readable as it uses XML or JSON.

2. Security. Contrariwise, SOAP has better security features than REST. SOAP provides digital signatures for message integrity checks. It also offers WSS standards for message-level signature & encryption support. Lastly, it delivers SAML support for federated identity management. 

3. Scalability. RESTful APIs' popularity relies on their simplicity and statelessness. These traits make it easier to scale APIs as the number of users and requests increases. Plus, RESTful increases traffic by adding more servers to the system. Nonetheless, SOAP messages are often larger than REST messages. These size issues can turn into slower performance and increased network traffic. SOAP can be scalable but may take more effort and infrastructure than REST.


APIs serve as a portal through which third-party apps can access a product's data and features. In this manner, they're crucial to building large and scalable apps. Even though there are many types of APIs, REST has become the most used. If you want to add third-party resources to your project, a REST API is a must!