A Guide to Application Programming Interfaces(APIs)
Tags: programming, api
Published: 2023-10-19 16:23:49

You may not be familiar with the functions or meaning of an API, but you have almost certainly come across them. 

APIs play a crucial role in the streaming of movies online, the sharing of recipes on Instagram, and the booking of flights through Emirates Airline.

This guide will take you through the meaning of Web APIs, how APIs work, API call and request methods, API keys, types, and benefits of API. Let's dive straight into the topic! 🚀


## What is an API?

An API means Application Programming Interfaces, which enable diverse software applications to establish communication and interaction via the Internet. APIs empower developers to connect with external data sources from third-party providers, such as weather service, payment gateways, video streaming, etc.

## How do APIs work?

APIs work by sharing data between applications, systems, and devices. This happens through a request and response cycle. A user initiates a request for data by interacting with an application. The request is sent to the API, which retrieves the data and returns it to the user.

## What is  API Call

An API call refers to the action of a client application sending a request to a server's API. It encompasses all subsequent processes following the submission of the request, which involves the API fetching data from the server and transmitting it back to the client.

## Request Method

There are four primary request methods for communicating with a server:

- GET: Used for fetching a resource
- POST: To create a new resource
- PUT: To edit or update an existing resource
- DELETE: To delete a resource.


## What is an API Key?

An API key is a distinct identification used to verify API calls. The key is a series of characters and numbers that identify the client. (Remember that the application or website is making the request.)

The client's access permissions determine whether the key grants or denies that request. The key also tracks how many queries are submitted for pricing and use purposes.

## Types of APIs

APIs come in a wide variety of forms, with numerous classification schemes. One way to classify APIs is based on who can access them. This includes the following:

**1**. **Private APIs**: Also referred to as internal APIs, private APIs are used only within an organization to link various software components and are not accessible to other parties. For example, in a social networking platform, one private API may manage the login process, another that controls the feed, and another that helps with user communication. There could be hundreds or even thousands of secret APIs in some apps.


**2**. **Public APIs**: Public APIs give third-party developers public access to an organization's data, functionality, or services, which they can incorporate into their applications. Some public APIs are free, while others are available as paid goods. For example, an e-commerce application may use a public payment API like Stripe to handle payment processing rather than building that feature from scratch.

**3.** **Partner APIs**: Partner APIs allow two or more firms to collaborate on a project by sharing data or functionality. They rely on authentication techniques to ensure that only authorized partners access them because they are not accessible to the general public.


## How to use an API

**1. Choose an API**.
First, you'll need to choose an API to integrate into your business. You may already be interested in an API, especially if you want to use one of the big names, such as the YouTube API. You might also wish to search by price – for example, you might want to start with a free API before moving on to commercial APIs.


**2. Get an API Key**
As mentioned, an API key is used to identify yourself as a valid client, set access permissions, and record your interactions with the API.

Some APIs make their keys freely available, while others require clients to pay for one. Either way, you'll need to sign up for the service then have a unique identifier assigned to you, which you will include in your calls.
Always keep your key private, like you would a password. If your key leaks, a bad actor could make API requests on your behalf. You may be able to void your old key and get a new one if such a breach occurs.

**3. Go over the API docs.**

API documentation is a how-to guide for using an API. It usually includes examples and lessons in addition to documentation.

Refer to the documentation for instructions on obtaining your key, sending requests, and retrieving resources from the server.

**4. Create an endpoint request.**
Write your first request. The most straightforward technique is structuring and sending requests using an HTTP client. 

**5. Link your app.**
You can sync your application with your API of choice now that you know how to make requests to it. 


##What are APIs used for?

APIs are incredibly versatile, and they support a wide range of use cases that include:

**Reducing Cost**

API helps to cut down development expenses by facilitating the reuse of pre-existing functionality, as opposed to the need for redundant development efforts.


**App Integration**

Another example of using an API to integrate systems, API helps to cut down development expenses by facilitating the reuse of pre-existing functionality, as opposed to the need for redundant development efforts.

Consider a scenario where you want to integrate your e-commerce platform with a third-party shipping service. By utilizing an API, you can automate calculating shipping costs, generating shipping labels, and tracking shipments when a customer places an order on your online store.

**Enhanced user experience**

Web APIs enhance the user experience by providing social media login options, geolocation services, weather forecasts, and more.
This is where Web APIs come into play, enabling you to integrate and offer these services to your users.


For instance, picture a scenario where users access your logistics app without essential features like tracking their shipments or utilizing interactive map functions. The app only displays static data, which doesn't create an optimal user experience.

## Wrapping Up

In conclusion, understanding the utilization of web APIs is a fundamental skill for developers looking to create interactive applications that significantly improve the user experience. 

In this article, you learned the various types of APIs, their advantages, and the underlying mechanics of how APIs operate. With this knowledge, developers are well-equipped to leverage the power of APIs and create dynamic, user-friendly applications.

Happy Coding