Now Hiring: We're looking for talented individuals to join our team!

If you run an online technology business, you must be familiar with the words API development. Due to its widespread use and outstanding results, “API” has become a popular term in software development.

APIs are everywhere, as we utilize them constantly. The online movie ticket you purchased, the discounted flights you booked, and the recipe from a blogger that you shared on Facebook were all made possible by APIs. You might be wondering how? Well, to know the answer, you’ll need to stick with this post as we’ll give you a brief overview of APIs and what they are. Why do you need an API? How do APIs work? and more.

So let’s get started!

What is an API?

APIs allow data to be exchanged from one software product to another. It connects two computers or programs. An API is a software interface that serves other software. An API is neither a database nor a server, as people believe. It is actually the code that governs the server’s access point.

Let’s use an example to clarify. When booking online, you enter your movie name, credit and debit card info, and print your tickets. What happens between entering your information and getting access? It’s APIs. They work behind the scenes to transmit desired data to other apps. This integration is seamless since you can’t tell when a software role changes.

How Does an API Work?

APIs work by sharing data and information between applications, systems, and devices. It acts as an intermediary layer that processes data transfer. Here’s how an API works:

api development working

  • User Request – In order to retrieve information, a client application makes an API request. This request contains headers, verbs, and something sent from an application to the web server via the API’s URI (User Resource Identifier).
  • Request to the Server – The API makes a call to the web server or external program after getting a valid request.
  • Response to the API – After sending a request to the server, the server responds to the API with the information requested.
  • Transfer Data – The data is transferred to the requesting application via the API.

For example, to book a flight, you must interact with the airline’s website in order to access the database and see if seats are available in your slot. What if the pricing is decided by the date, popularity of the route, flight time, and so on? You must obtain all of that information from the airline’s database, whether you are communicating with it through an online travel service or a website.

If you need to get the data, the application must interact with the airline’s API and give it access to the airline’s data. APIs help you run and deliver the data from the application you are using to the airline’s system. It also takes the responsibility of the airlines to your request and delivers right back to the application you have been using.

Why Do We Need API?

APIs are necessary for the development of robust apps since they facilitate the recovery of functionality and simplify coding for developers. Furthermore, they provide secure connections between servers, which improves security. The application programming interface (API) acts as an intermediary between systems by translating data formats into something the other program easily understands. This helps reduce the incompatibility between systems and eliminates the need for costly software conversions. If you are still on the fence, take a look at the three main reasons that help you answer why you need an API?

  • APIs help companies grow by allowing third-party apps and websites to access their systems.
  • APIs enable data integration across multiple platforms.
  • APIs make data more controllable and accessible.

API Examples

API examples abound in your everyday life, whether you realise it or not. APIs are the primary software architecture that ensures that different software can work together.

You may not have recognised how crucial software collaboration is or how frequently it occurs behind the scenes until today. Let’s see some of the best examples of API:

Google Maps

Google Maps API gives ease to users by providing them with nearly limitless geographical aptitude at their fingertips. You can search nearby restaurants, niche shops, and whatever else is relative to your location. You may have been using this API example more often without realizing it.

Booking Comparisons

Have you ever thought about how travel booking websites can provide you with thousands of flights and destinations and show you the cheapest option? Well, the answer is by using third-party APIs. If you make a flight ticket booking or train ticket booking, they will use APIs to confirm the trip with the provider they sourced it from.

Third-Party Payment Processing

The third-party payment processor APIs enable merchants to accept online payments by credit or debit card without setting up their own merchant accounts. You don’t have to think about setting up or maintaining a merchant account. Simply create an account with a third-party payment API and have all your transactions go through them.

Universal Login

With Universal Login, users do not have to go through a time-consuming registration process. Instead, the sign-in process is simplified by delegating the login functionality to third-party services such as Facebook, Google, Twitter, and other websites. Users can sign up through their favourite social media platform


Another example of APIs is a range of bots on Twitter. Twitter bots are accounts that automatically tweet, follow, and send direct messages based on software instructions. All boats on Twitter are powered by the Twitter API, which allows you to execute simple actions like tweeting a certain phrase or following a user.

What Are the Different Types of APIs?

We can classify Web APIs into categories by the desired level of access and use. There are four main types of API that are commonly used in web-based applications:

Public APIs

Public APIs are also known as Open APIs are available for any third-party developer. There are two types of public APIs one is Open which is also free of cost, and the other one is commercial. In Open API, all features are general and can be used without restrictive terms and conditions. Whereas Commercial API, users pay subscription fees or use APIs on a pay-as-you-go basis. A famous approach among publishers is to offer free trials, so users can evaluate APIs before purchasing subscriptions.

Private APIs

Private APIs, or you can also say internal APIs, are specially designed to improve an organization’s solutions and services. Developers can use these APIs to integrate the company’s IT systems or applications, build new techniques or customer-facing applications’ existing systems. The interface remains open only for those working directly with the API publisher if the application is publicly available. The amazing thing about APIs is that they enable a company to control API usage fully.

Partner APIs

Partner APIs are openly promoted and shared with business partners who have signed an agreement with the publisher. The most common use of this API is for software integration between two parties. A company that grants partners access to capability or data benefits from extra revenue streams. At the same time, it can monitor how the exposed digital assets are used, ensure whether third-party solutions using their APIs give a great user experience, and maintain corporate identity in their applications.

Composite APIs

Composite APIs combine service APIs or multiple data sets, built by using the API orchestration capabilities of an API creation tool. They enable software developers to access different endpoints in one call. For instance, composite APIs are pretty useful in a microservices architecture pattern where you need information from several services to perform a single task.

API Protocols and Architectures

An API protocol defines the rules for API calls as it specifies accepted data types and commands. Different API architectures specify various protocol constraints. Let’s look at different API architectures.


REST stands for Representational State Transfer, an architectural style that defines a set of constraints to create web services. The Rest API allows flexible and simple access to web services without processing. The REST API is preferred to SOAP (Easy Object Access Protocol) since it’s more versatile, simple, and uses less bandwidth. This API retrieves web service data. All REST API connections require HTTP.


SOAP, short for Simple Object Access Protocol, was a Web communication protocol created by Microsoft in 1998. It exposes web services and transmits data over HTTP and HTTPS. SOAP supports just XML and follows strict standards such as communication structure, encoding requirements, and processing requests and responses.


GraphQL is an API query language that uses existing data. It’s a back-end service feature that lets developers request data from the database. GraphQL gives API developers a full, intelligible data description. It permits easy API evolution and comprehensive developer tools.


RPC is the simplest and oldest method of API interaction used for client-server applications. It’s a subroutine or function call. RPC is based on procedure calls, therefore the called procedure need not exist in the same address space. RPC is ideal for client-server interactions with lingering control flow.

Terminologies of API Development

We compiled a list of the most commonly used API terminology to provide you with quick and easy definitions so you can learn more about APIs. Please refer to the list below:

HTTP Methods

HTTP methods are a collection of request methods that indicate the desired action for a given resource. The following are the most common HTTP methods:

  • GET: The method is used to get a representation of a resource. GET requests should only fetch data.
  • HEAD: The method requests the same response as a GET request but without the body.
  • POST: The method sends an entity to the specified resource, causing the server to alter the state or have side effects.
  • PUT: The method uses the request payload to replace all existing representations of the target resource.
  • DELETE: The method deletes the specified resource.


API headers allow the client and server to send additional data with an HTTP request or response. The server uses headers to process requests.

Request & Response

An API request happens when a call to a server is made using an API. The data sent back to you is called a response.


API parameters are parameters that can be given along with an endpoint to alter the response. They can be sent using the GET and POST methods.

Access Token

Token-based authentication uses access tokens to allow an application to access an API. After a user successfully authenticates and approves access, the application obtains an access token, which it uses as a credential when using the target API.


An API key is a one-of-a-kind identification that allows a user, developer, or calling application to access an API. However, instead of a human user, they are usually used to authenticate a project with the API.

Consumer Key and Secret

An API key issued by a service provider is known as a consumer key (such as Twitter or Facebook). The consumer is identified by this key. The consumer secret, on the other hand, is the “password” used in conjunction with the consumer key to request access to a user’s resources from a service provider.


An API endpoint is a digital address where the API receives queries and responds.


JSON is the most popular data format for storing and transporting information. The JSON format is commonly used for API responses because it is lightweight and fast.


Latency in API is the total time the API system takes to respond to API calls.

Rate Limit

A rate limit is the maximum number of API requests made by a user or app in a given amount of time. A rate limit protects an API from accidental or malicious overuse.

API Throttling

Restricting the number of API requests a user may make in a given period is known as API throttling. API throttling helps counter denial of service (DoS) attacks, where a malicious user makes large amounts of requests to shut down the application.


OAuth is a protocol that allows programs to grant “secure delegated access” to client applications. OAuth uses access tokens rather than passwords to authorize devices, APIs, servers, and apps over HTTPS. OAuth comes in two versions: OAuth 1.0 and OAuth 2.0.

Useful Tools for API Development

While there are several API design tools and technologies available, the most often used API development technologies and tools for designing APIs for developers include:


Apigee is an API management tool offered by Google to help companies build and scale apps, APIs, and data. Hundreds of businesses rely on Apigee to create, protect, test, and grow APIs while keeping visibility and control.


Dredd is an HTTP API Testing Framework for validating API description documents against the backend implementation of the API. It validates your API responses step by step, as described in the documentation.


Sandbox helps developers to mock RESTful API and SOAP web services quickly and easily. It automatically generates mock web services from API definitions and helps with instant deployment.


Postman offers a full suite of API development, testing, and modification tools. It is the most widely used API testing tool on the internet. Postman is used by millions of developers to make API development simple and straightforward.


SoapUI is an open-source automated testing tool for SOAP and REST APIs. It is widely used for web service inspection, development, invoking, mocking, functional testing, and load and compliance testing. It supports various standard protocols such as HTTP, HTTPS, REST, JMS, AMF, JDBC, SOAP, etc.


Swagger is an open-source framework that provides a complete set of API development tools for designing, building, documenting, and consuming REST APIs that adhere to the Open API specification. Swagger is currently the most popular API design framework. It was recently transferred to the Linux Foundation under the name The Open API Initiative, and it is supported by companies such as Google, Microsoft, Intuit, and Atlassian.


LoadView is a browser-based solution for website load and stress testing. It enables development teams to forecast how a website, web application, API, and other applications will perform under various traffic and workload scenarios.


JMeter is one of the most popular and user-friendly tools for API testing.

What Makes a Good API?

Authorization & Authentication

Authentication verifies a client’s API connection. Even if the client has already connected, each call to a REST API must be separately authenticated to preserve stateless transfer. Regarding authorization, it comes after authentication: after verifying that a client connection is valid, permissions must be issued to limit what the client may do and what resources they have access to.

Search by Criteria

A good application programming interface (API) should let you search datasets based on certain criteria. When a user needs to view a dataset based on specific conditions or filters, the function is a big help and is very convenient to use.


Another thing you need to do is paging, which is the process of splitting data into discrete pages, that should be implemented when you create RESTful APIs that could provide large amounts of data.


Sorting is another name on the list; It’s a must-have feature for any endpoint that delivers a large amount of data. Your API users may want to sort by last changed date or email if you’re returning a list of users. Many APIs include a sort or sort by URL option that can be set to a field name to enable sorting.

JSON Support

JSON API is an HTTP-compatible format. It specifies how clients should request or change data from a server and how the server should react.

Data Validation

Data validation is about checking the quality and accuracy of source data before using, importing, or processing data. One can perform different types of validation depending on destination constraints or objectives. Data validation is a form of data cleansing.

Best Practices for API Development

Go With Error Status Code

You’ll find a status code for everything, from determining why a session was rejected to locating a missing service. The usage of status codes in REST API design is useful for developers. And they can rapidly detect an issue with status codes, which cuts down on analytics time for all types of problems.

Rate Limit

Rate-Limiting refers to the broader concept of limiting request volume to an API endpoint at anyone. Public APIs use rate-limiting for commercial purposes to get more and more revenue. And a common business model pays a certain subscription amount for leveraging the API. As a result, they can only make API requests before upgrading to a more expensive plan.


You always need to log in to the HTTP response code from each request. This will enable you to go back and see whether there was an issue with a certain submission and initiate automated retries.

Well-Compiled Documentation

You need to make sure that your API documentation “makes sense” to the developer audience by including the following information: A quick overview of the API’s capabilities. There are instructions, examples, and code samples for each service that the API makes available. The writing is clear, concise, and simple to comprehend.


It places a cap on the number of API requests that a user can execute in a specified amount of time. The infrastructure is at risk of being maliciously or accidentally overloaded if the throttling configuration is not implemented correctly.

Support X-HTTP-METHOD-Override

One should support X-HTTP-Method-Override as the HTTP header works similarly to a hack. When contacting your Web API via JavaScript or an XMLHttpRequest object from a web browser via an HTTP POST request, you can add the header with a value of PUT or DELETE.


Now, this is the most essential API development practice you should focus on as it is the process of preventing attacks on APIs. APIs are becoming the main target for attackers since they are widely utilized and provide access to critical program functionalities and data. API security is an important aspect of online application security today.

FAQs About Api Development

What’s the difference between SOAP and REST API?

Representational state transfer (REST) is an architectural design pattern for building web services. On the other hand, SOAP (Simple Object Access Protocol) is a protocol that follows a strict standard to allow communication between the client and the server.

What is required for API development?

API development generally includes functional and nonfunctional requirements (How your API should perform in terms of service level agreements). Moreover, it also consists of a third type and i.e., the way your system implements requirements.

What are some styles for API development?

There are many options that one can use to design or implement APIs. Before choosing a specific technology, it is good to explore and understand the main API styles. Here are some sorts of API development REST APIs, SOAP APIs, GraphQL APIs, gRPC.

What exactly is an API when it comes to developing software?

Application programming interface, also known as API, refers to a collection of specifications and protocols that are used to construct and integrate application software.

How much does it cost to develop an API?

It’s critical to understand that an API application interface (API) is more than just coding. Whether a new project is assigned to an in-house team or a business owner intends to hire an outsourcing provider. Several factors determine the cost of API.

How long does it take to develop an API?

There is no clear way to set a schedule for API development without knowing a few specific facts about your needs, circumstances, skills, and resources. If you have all these pieces of information to hand, estimating a completion timeline is not that tricky.

Wrapping Up

APIs are an integral part of the business that can navigate the digital age. As organizations integrate IoT and other intelligent technologies into their ecosystem, API-driven strategies are necessary for success because they enable you to enhance consumer engagement, optimize business operations, and launch new goods and services.

If you are in the process of developing an API and are looking for professional assistance. You can contact us; we have experts who will help you in the complete API development. We can help you bring new possibilities and business opportunities for your company through our unique API solutions.

Related Posts

Analyze your business's potential and look for prospects for growth.