Effective Strategies 7 min read

Everything You Need to Know About APIs

This article will discuss APIs, including what they are, how they work, their types, their importance, their benefits, and finally, an example to show how an API can be created.

Everything You Need to Know About APIs

You must have always heard the saying from time to time, “communication is the key”. Whether it be a relationship between two people or a group of engineers working on a project, communication is an important characteristic. We humans communicate through language; similarly, applications we use daily, like social media platforms, communicate through software called Application Programming Interface (API). Therefore, we need to see how the APIs have brought about an impact on the applications.

In this article, we will discuss everything about APIs, including what they are, how they work, their types, their importance, their benefits, and finally, an example to show how an API can be created.

What is an API?

Before diving too much into technical details, let’s first understand what an API is. An API is a set of rules that enables software applications to communicate with one another and is known as an API (Application Programming Interface). It sets up the ground for data transmission between different applications. For example, when you log in to your Netflix account, the login API sends your login credentials to the server, retrieves your profile information, and displays your watched movies, TV shows, etc.

They are used in almost every application that is built because it is easy and faster to implement and allow rapid data transmission and access to the applications. It is simply the connection between two pieces of software.

Let’s see how APIs are even capable of doing that.

How Does an API Work?

Let's start with an example for better understanding. Suppose you are a tour guide who needs to show your customers different locations around the city. You know the locations, but you do not have access to transportation. From this example, we can say that the driver acts as a middleman who takes you and your customers to different locations. In this case, we can say that the API can be considered the driver.

Similarly, an API is an intermediary between an application user and the server. An API engages communication between the server and the application whenever a user asks for a request. API retrieves the specific information the user asks for and delivers it to the application to be displayed to the user. The image below explains the flow of the request:

The Flow of the API Request

What are the Different Types of APIs?

Three main types of APIs are categorized based on user access: Private APIs, Partner APIs, and Public APIs. Public APIs are further subdivided into two, Open APIs and Commercial APIs.

Types of API

Private APIs

A Private API, or Internal API, is used within an organization or enterprise to connect its systems and data. The developers working within the organization make use of them to connect their various departmental applications. For example, a private API can connect sales with marketing systems. In short, the organization holds power over those APIs and is only restricted within their premises.

Partner APIs

Partner APIs are used by an organization's business partners bound under the agreement contract. Software integration occurs between these two organizations, where the publisher and partner agree on the terms. A partner API enhances the service's worth and creates a sales channel for upselling.

Public APIs

Third-party developers or common people can use public APIs. These kinds of APIs can increase the revenue stream, assist in reaching wider audiences and boosting traffic, and a wide range of business initiatives without requiring a closed or written agreement relationship between the user and the publisher. These are subdivided into two, Open and Commercial.

Open APIs

These APIs do not have any restrictions that limit the user according to their usage. The developers access available documentation that can be used to test and build applications, and there is no fee associated with using them.

Commercial APIs

These APIs require a subscription fee to use them. However, publishers frequently provide a free trial for users to test and review the product so that the customer can decide whether or not to buy a subscription.

Some Protocols Used by APIs

Different web services exchange data using standardized API protocols. This makes it possible to access numerous different systems using a variety of programming languages and operating systems. Some of the widely used API protocols are:

Remote Procedure Call (RPC)

RPC enables resource exchange principles to be used in web APIs. A client and a server interact where the client remotely calls a server method, and the server then runs the process.

Service Object Access Protocol (SOAP)

This protocol is designed for exchanging structured data in a distributed, decentralized setting. Applications that comply with these requirements can communicate with the system using SMTP (Simple Mail Transfer Protocol) or HTTP (Hypertext Transfer Protocol). SOAP is most widely used in corporate web-based applications to guarantee data security. For example, SOAP APIs are used in financial payment gateways, telecommunication services, CRM solutions, and identity protection.

Representational State Transfer (REST)

REST APIs are also referred to as RESTful APIs. The use of REST APIs in Web Services has become more widespread lately. It is considered an alternative to SOAP since many developers find it difficult to use because they have to write a lot of code to complete a task. In addition, accessing data and resources is simpler with REST because it operates so programmers can use HTTP functions to send and receive requests, such as GET, PUT, POST, and DELETE methods.

One of the reasons REST is such a popular choice for building public APIs these days is its ability to support a variety of data formats for storage and exchange. These systems can send messages in plain text, Javascript, YAML, XML, and JSON, whereas SOAP can only send messages in XML.


GraphQL is a query language for APIs. It allows customers to provide specifics about the required data. It simplifies adding data from multiple sources, allowing the developer to make only one API call to obtain the desired information. It was created in response to the demand for more efficient data loading, quicker feature development, and improved mobile adaptability.

Benefits of Using APIs

APIs have brought various business potentials and shown a scalable path to their workflows. Some of them are mentioned below:

●     Integration: The connection between various software systems allowing scalable businesses.

●     Adds value proposition: Allows developers to integrate services already provided by the top companies like Twitter, Google, and Amazon API services to make their applications more interactive and attractive.

●     Promotes innovation: Allows developers to develop new applications on top of the existing resources.

●     Automation: Less human effort and intervention required, basically acts as a service to be used.

●     Adaptability: The ability to adapt to the changes in data integration and migration in various applications, allowing the flexibility of services.

A Step-by-Step Guide to Designing an API Using Apidog

Apidog is an API documentation and testing tool that assists developers in designing, documenting, debugging, testing, and mocking their APIs. It is intended to make creating and managing APIs easier by providing an intuitive and user-friendly interface. Apidog is available in cloud-based and self-hosted versions and supports various programming languages and API frameworks.

Following are the simple steps to create an API using Apidog:

Step 1: Creating a New Project

Open the Apidog application and create a new API endpoint.

Creating a New Project

Step 2: Select the Desired API Request

Select the API request verb you want to perform, like GET, POST, PUT, DELETE, etc.

Select the Desired API Request

Suppose, for this example, we will be creating a POST request. Now we will enter the details in the Name field - stating the purpose of this API, like, Adding a new pet to the store, and adding a tag to identify the query, pet, as highlighted in the image below.

Create a Post Request

Step 3: Adding the Desired Fields

Next, we will add the fields we need to POST under the field name and set their required data types.

Add the Desired Fields

For the sake of completion, some of the fields are added to show you what the result would look like after you are done adding the fields.

Finish Post API Request

Step 4: Generating the JSON for Fields

Now that we have created our desired fields, we need to generate our JSON for the API that will consist of the values of the set fields. To do that, you would need to click on Add Example as highlighted below:

Generate the JSON for Fields

It will then pop up a window for you to add values. Although, if you want to test whether your API works, Apidog has provided the option of Generate Automatically, which will assign random values to the fields.

Generate Automatically
Add Example on Apidog

Step 5: Run Your API Request

Lastly, click Run to check if your API request has been performed successfully. You will receive the following result:

Run Your API Request

Congratulations! You have successfully created a POST request API endpoint.

Final Words

In this article, we have demonstrated everything you need to know about API from scratch. Its significance in the current technological landscape, followed by an example shown through Apidog, has made the user journey for API development, debugging, testing, mocking, and publishing API documentation easier, more interactive, and feasible. And lastly, the growing demand for resource exchange and communication channels among business and consumer software applications nowadays.

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