A Quick Guide to the Most Common API Styles

An API (Application Programming Interface) is a piece of software that allows for two apps to exchange information. They allow us to simplify IT architecture, streamline processes and share data sets faster.

Nowadays, many options can be used to design or implement APIs. Before rushing into choosing one specific technology, it is essential to explore and understand the main API styles.

Picking a style is a design choice meant to manage the way an API is developed. The decision should be made based on the needs of both the developers and the users.

The most important thing to keep in mind is that there is no “best style.” We compiled a list of styles that are good to keep in mind when starting to develop an API.

The main API styles

APIs come in different shapes and sizes. Public ones have no limit on who can use them, while partner ones require developers to have specific licenses in order to gain access. They can also be created for internal use within an organization to optimize the development of in-house goods. Because of the versatility of APIs, there are also plenty of styles they come in. Let’s take a look at the five most common API styles.

1. REST

REST (representational state transfer) is an architectural style, which combines a client/server architecture with additional constraints that define a uniform interface. API developers can implement it in a variety of ways.

When a client request is made through a RESTful API, it transfers a representation of the state of the resource to the endpoint. This information is then delivered as one of several formats through HTTP: JSON, PHP, and XLT, among others.

When it comes to the HTTP request, headers and parameters are essential for this particular style. They contain crucial identifier information about the request’s metadata, authorization, cookies, and more.

REST is a set of versatile rules which can be implemented as needed, making REST APIs faster and more adaptable than other APIs. Due to reduced security requirements, browser client compatibility, accessibility data health, and more, this particular style is considered the most common on the Internet. It is also considered more straightforward to use than the following style, Simple Object Access Protocol.

2. SOAP

SOAP is a communication protocol system that connects processes using different operating systems to communicate through HTTP and XML. SOAP APIs are designed to handle records like accounts and passwords.

Unlike the REST pattern, SOAP is mainly based on HTTP and XML data format only and follows preset standards such as messaging structure, a set of encoding rules, and a convention for providing procedure requests and responses.

One of the most important SOAP features is built-in error handling. If you encounter a problem with your request, the response contains valuable error information. The report even provides standardized codes, which makes automating the correction process more accessible.

With SOAP, you are not limited to using only HTTP transport. You can also use SMTP (Simple Mail Transfer Protocol) when working with Python and PHP languages.

3. GraphQL

GraphQL is a language for querying databases from client-side applications. It’s typically used over HTTP, where you can POST a “query” to an endpoint instead of hitting different HTTP endpoints for various resources. GraphQL offers more flexibility and enables the client to request precise data.

A GraphQL server creates a pre-made model of the data which can be requested. In other words, the framework serves as a middle ground between the client and the server while defining how to access the information.

The model, also known as schema, defines what queries are allowed to be made, what types of information can be collected, and how they interact. You can create a GraphQL schema in any programming language.

Through the schema, the client can validate the query and make sure the server will be able to respond. A GraphQL query closely matches the result, which eliminates the possibility of receiving erroneous data or none at all.

4. Falcor

Falcor is somewhat similar to GraphQL. It introduces a virtual layer that is used to trace frontend requests to backend services.

At its basic, the style creates a virtual JSON resource, which is used as a container. This virtual resource is published under a URL address. Then, various backends and data sources are linked into the container. The virtual JSON resource is designed to be extended over time.

Clients don’t have to retrieve the entire resource. They can identify which part of the resource is of interest and select it for retrieval.

5. gRPC

This style is an implementation of Remote Procedure Call. RPC is an architectural style for distributed systems. The central concept of RPC is the procedures. They don’t need to run on the local machine and are able to run on a remote machine in the system. In this case, calling a remote procedure is similar to calling a local one.

This type of style is language-neutral, platform-neutral, and faster than other styles. It uses Protocol Buffers (protobufs) to serialize the service- and message-data intro binary stream and the HTTP/2 standard for optimized binary transfers.

The most common usage for gRPC includes gathering services into a microservices style architecture or connecting mobile devices to backend services.

Plenty of Options

When it comes to choosing an API style, it all boils down to what you prefer and what you want to achieve. This is just a quick guide to get you started on your API research. We recommend starting with the most common ones: REST and SOAP.

Most developers prefer RESTful architecture simply because it uses less bandwidth and is easier to understand than other styles. RESTful APIs have been widely adopted and are considered an essential part of the Internet. However, SOAP is also valuable for very particular situations, like ensuring that your transactions are unreachable by third parties.

Want to learn more about the two most widely used API styles? Read about the REST vs. SOAP debate here and continue your research into the world of APIs.