All you know about API Development a Complete Guide– 2021

by | Jul 10, 2021 | Development, Technology

Mobile Applications are the base of future businesses, and we are entirely going to depend upon the technologies that help build Applications. Technologies without them developers cannot assemble different segments of Application development, and one of the most critical aspects of this process is API.

In simple words, API is Application Programming Interface, it plays an essential link between different technologies and segments of development that’s why developers always have a positive attitude for it, and they both work as best mates in the development of Mobile applications.

In this blog, we will explore different aspects related to API and thoroughly dig deep into the world of API development.

In this blog, we are going to emphasize the following:

  • What is API?
  • Needs of API?
  • Types of API
  • How does an API work?
  • Terminologies associated with API
  • Key characteristics of API Development
  • 5 best exercises of API
  • Tools for API development
  • Why do businesses need an API?

What is API?
In simple language, an API is a process of connecting different computer programs to link and communicate with each other. It permits the software to talk to each other, exchange and transmit data. So, an API is a set of programming codes that works as a software mediator between different computer technologies. And it makes the task of creating a mobile app simple and easy by giving it rapid speed and more flexibility.

An API consists of a set of protocols, definitions, instructions, and standards that will allow them to integrate and perform useful work with other applications. Each API will follow an API identification, that is, a standard that defines how the API will be created. The internal details and data of the API remain hidden, and only the interface is disclosed. And only the programmer who works on the project of making its software is known to it.

In almost all applications where there is communication occurring between two entities, API is used. It helps programmers to carry out the development process without wasting time going deep into the coding. Furthermore, utilizing the existing APIs to do similar functions again has removed the need for developing or creating them from scratch, thereby it saves much more time and muscle.

When Do You Need an API?
Every software-based business must build APIs, are you one of them who think that? Well, it is indeed a popular mobile application development market trend, but make it clear that you don’t certainly have to build or create APIs for your business solution.

Do you think if every software-based business must build APIs? While it is indeed a popular mobile app development trend, let me tell you that you don’t necessarily have to build APIs for your business solutions. Even though it has many advantages, it might not be appropriate or feasible for small or non-technical businesses.

So how would you know if you need an API or not? Go through the below-given points.

  • Basically, an API is created if you want to develop a mobile or desktop application. In spite of building a landing page or blog, you are not required to build an API.
  • Suppose, if your app is in the interim and planning to use it for a temporary purpose and doesn’t have any idea to expand or scale it further. In that case, we don’t require an API.
  • If you want to access data in different ways from different sources.
  • While using JavaScript’s popular and well-admired frameworks like React or Angular, you don’t need to create an API.

If you have a website that is full of meaningful, logical, and well-organized data and you are planning to excellent your performance, in this case, use APIs.

Types of API
API development has its own dominion, there are several kinds of APIs created to fulfill different requirements. Each class has a particular function and adheres to a specific standard. Let us take a look at the classification of APIs concerning their release policies.

Private APIs: Used for internal operations, these APIs are meant to support development within an organization. Private APIs can only be approached by in-house developers and by external employees working with the organization on a contract basis. Thus, the APIs remain in complete control and charge of the company.

Partner APIs: Partner APIs, as is evident from their name, are shared among different partners or parties. The API sharing is on the basis of an agreement between the business partners and the API publisher. Companies use it as a source for gaining additional income. In such cases, they strive to ensure that the solutions that use their APIs provide a good quality experience.

Public APIs: Open for the public, these APIs can be used and customized by anyone. Third-party developers can use these APIs to develop and tweak the features of their apps. Public APIs are – open and commercial. Open APIs do not have any type of restrictions or conditions. Open APIs can be used to create and test apps for free. Commercial APIs as the name suggested is the paid APIs, need a subscription fee or work on a pay-as-you-go model. Such APIs offer free trials for buyers.

Composite APIs: They unites the existing API functions of different data and service APIs to bring together various tasks under a common interface. This enhances the speed and improves the application performance.

How an API Works
Now, to know about the working of an API, we have first to identify the building blocks of an API. There are three key elements correlated with an API i.e Data source, Request, and Response.

A Data source refers to a database where programmers store data, databases like MySQL, Redis, Oracle, or even a simple spreadsheet file. Now the second element is “request” i.e How an API is accessed. Programmers create a request when they want to use an API. The requests must follow a predefined format. And the last element, response, is what an API returns once a request is processed. The response also has a specified form that it needs to follow.

Here you might feel a little confused? Let me elaborate on working with the help of an example to help you understand better. For example, you want to book an event location and explore an event booking app/website to find a suitable place. You share all the details like capacity, date, time, required amenities, etc. Once you submit the details, you receive a list of suitable event venues with more information like availability, timing, and price. What do you think happened here? Yes, these are APIs.

When you search for an event location or any other particular info, the platform sends a request to access the database through API. A response holds the relevant data and delivers it to the platform through the help of API (like fetching the info from storage), and then the platform displays it for the end-user, and that is you. That’s how an API works as a medium or intermediate and enables data sharing by establishing a connection. This is how an API works! The implementation of several complex and innovative mobile app ideas can be simplified with the help of APIs.

Terminologies associated with API
To better understand the concept of API development, we must be familiar with the fundamental terminologies involved in the process. So let’s see what these terminologies are.

API Key: When an API request is created by the developer, a unique code is passed to acknowledge the requester. It’s called an API key.

Endpoints: Endpoints are the Interaction touchpoints. When API communicates with another system is called Endpoint.

GET: A RESTful API’s HTTP method is used to request data from the server of the desired resource.

REST: Representational State Transfer (REST) is a programming architecture used to improve the communication between two systems. Systems that use or implement this architecture are called RESTful systems.

Rate-limiting: It is the process of limiting and controlling the rate of incoming and outgoing traffic to an API. It also restricts the number of requests that a user can make to an API at a time.

JSON: JavaScript Object Notation (JSON) is a data format used by APIs during data exchange, that is, request and response.

API throttling: It is the process of controlling the usage of APIs by users for a specific/limited period of time. So once you set an API throttling limit and the user exceeds that limit, he will receive a limit exceeded message.

OAuth: OAuth is an open standard authorization framework that allows secure access to user’s data when third-party apps require it.

GET: A RESTful API’s HTTP method is used to request data from the server of the desired resource.

POST: A RESTful API’s HTTP method is used to send data to the server for creating a resource.

SOAP: Simple Object Access Protocol represents as SOAP is a messaging protocol used for sharing structured information while performing web services. By implementing with XML information set and application layer protocols, it executes message format, negotiation, and transmission.

Latency: It denotes the total amount of time an API took to complete a request and response.

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Essential Features in API development
Before discussing the developing application programming interface, we must understand the significant features that an effective API should have. So, let us take a look at some of the must-have features of APIs.

  1. Paging
    Paging a vital feature that is used to understand and determine what data are to be displayed and at what frequency. It is necessary because when databases grow in size, retrieving specific resources may take a longer time. And in some cases, the user may require only partial data and not complete data. In this type of case, paging and sorting – ensuring that users can retrieve data based on certain conditions—are very beneficial. This helps to enhance processing/loading and improve the response time.

2. Authentication
Authentication is mandatory for an API if you want to set any limits on its usage. It means verifying the identity of those particular users who will have access to your API. Will it be available only for internal employees, or can anyone use it- its essential to set the authentication rights.

3. Speed
The speed of an API directly results in success. Powerful APIs take less than 100 ms to respond. Of course, it depends on the functionality of the API, its users, and such, but whatever it may be, a slow responding API can never be a good one.

4. Scalability
A quality API must have scalability as one of its features and have the capability to go up and down depending upon the demand of the user. For instance, a good scalable API must be able to operate 5000 users in a day and 5000 on another day without causing any disturbance.

5. Validation
Verification of the correctness of the data is crucial in API development. This process, called validation, is of two types- server-side validation and client-side validation. Server-side validation supervises the validation of property details, duplication possibilities, its other needs, etc. Client-side validation includes providing accurate feedback with visible error marking.

6. Testing
Just like software testing, API testing is also essential to check the performance of APIs as well as their integration capabilities. In testing functionality, security, performance, and reliability of APIs are checked to ensure that they meet the set expectations. Famous tools used for API testing are Postman, SoapUI, and JMeter.

7. Rate Limiting
If you have a public API, you are required to implement rate-limiting to ensure that your API is not being exploited. People may use public APIs excessively, and all these requests may make your API crash. To handle this situation, a limit can be set on API usage.

8. Logging
When the API is being used by third parties, you might want to track its usage. If you log every response and request, it’s simple for you to run analytics on API performance, monitor its errors, and identify its failure structure.

9. JSON Support
A productive API should tool JSON support or RESTful APIs. REST APIs, being lightweight, stateless, and familiar with syntax (to other programming languages for app development), provide excellent ease of development for app developers.

Five Best Practices for API Development
The development of APIs is an organized process, and to make it entirely successful, it must obey some defined best practices. If you want to build an effective API, you must consider these practices and follow them religiously. We will discuss the top five key practices in this segment.

  1. Libraries and SDK: Improving the speed of API creation and implementation is a fair practice for all APIs. By using libraries and SDK that have reusable codes and processes. It also encourages mobile app developers to use it because it helps to boost speed.

2. Throttling: It is a must-follow practice to control and redirect traffic overflow. Throttling helps in API backups and also safeguards it from the DoS (Denial of Service) attack. Also, it’s one of the best options to keep the API gateway as an enforcement point that manages data access to the right users.

3. Security: Mobile app consist of crucial info of the users from personal data to bank details and this is why security should be a key concern while building APIs.

4. Permit HTTP method overriding: When you develop APIs, you also need to allow RESTful APIs to override HTTP methods. The reason behind it because some proxies only approve POST and GET methods.

5. Documentation: All APIs should come with documentation that will guide the developers who are using them. This documentation includes details like the type and format of requests, type of responses, allowed requests, format, etc. Such documentation is needed for developers to ensure the easy integration of APIs into their software. It helps in reducing implementation time and also improves API efficiency.

Tools for API Development
Tools are technologies that help in the development of APIs, there are various tools and technologies available in the market. To get a complete picture of building an API, you need to be familiar with what they are. So, in this section, we will look at some of the popular tools that developers use.

Apigee: It is an API management tool by Google, which encourages developers to enhance their API approach.

Postman: A popular tool that aids the development of APIs, Postman, is used to evaluate the performance of APIs.

GitHub: GitHub is an open-source repository service that allows developers manage their code files.

APIMatic: An excellent and must-have tool used by developers to generate high-quality SDKs for APIs. It’s a further aid to sync it with the updated API. In addition, by using APIMatic, developers can convert API descriptions into other formats like WADL, Swagger, API Blueprint, etc.

SoapUI: It is a cross-platform, open-source testing tool, SoapUI is utilized to conduct all kinds of tests- security, compliance execution, load tests, and regression for web APIs. It is an outstanding tool that assists in automating both functional and non-functional tests.

Why Your Business Needs an API
While reading and understanding about building an APIs, a thought must have crossed your mind “why to spend extra time on building an API first when it will delay the time launch.” Which is valid as well. While the API first approach does bring about a delay in time to market, its advantages are too many to exceed this concern. Want to know what they are?

Simple Interface: When a user is checking/accessing an API, he will only see the necessary details. All the internal complexities and difficulties are hidden under the API. This encourages developers to implement easy and faster APIs.

Early Feedback: With API’s first approach, it became possible to validate early on during the development process. So if there are any changes to be done or new inputs to be added, it can be decided ahead of time.

Reduces Dependencies: APIs aid to bring independence to an extent in the development process. Using APIs, developers can independently perform their work without waiting for others or depend upon a third person to execute their work. Therefore, this makes the developer work in parallel to pull down the development time and efforts.

Eliminate Constraints: A code-first approach leads to several constraints while designing the behavior of services. This can also impact the developer experience and create bottlenecks. Employing an API first approach instead can help to free the design from such issues.

An API-first approach has significant benefits in both business perspectives as well as software development. By building required APIs and implementing desired technological connectivity, APIs enhance the development process and improve business profits.