10 Popular API Examples: A Full List

Every time you use an app such as Facebook or Instagram, check the weather or send an instant message, you’re using an API. API examples are everywhere, in the applications you use on a daily basis. 
 

APIs are basically the middlemen of apps and web services, allowing different applications to communicate with each other. They are a key aspect of our digital world and in software development. With APIs, we are able to engage in digital experiences on our phones and computers every day. 
 

In this article, you will get to learn about:

1. Twitter API
2. ChatGPT API
3. Google Map API
4. Discord API
5. Github API
6. Paypal API
7. eCommerce API
8. YouTube API
9. Instagram API
10. Slack API

What is an API?

We’ll explain the concept of an API from both a technical and non-technical point of view. 

APIs (Application Programming Interfaces) are like bridges that let two applications talk to each other. They define the rules and methods for how these apps can interact. 

For example, a weather app wants to show the current temperature. To do that, it sends a request for temperature data through an API to a weather server, which processes the request and sends back the weather data, also through the API. The app can then display the data for for you.

Let’s look at APIs from a more common and non-technical perspective. 

Imagine you're at a restaurant. The menu represents the API. You choose a dish from the menu (make a request), and the waiter (the API) takes your order to the kitchen (the server). The kitchen prepares your food (processes the request), and the waiter brings it back to your table (delivers the response).
 

In a way, an API is like a bridge or a middleman that connects two different apps. If application A wants to gain access to information/functionality from application B, it sends out an instruction (i.e. the API). Application B reads the instruction, and returns the requested information to application A.

How To Use An API?

Types of API

There are so many types of APIs. Below are several of them:
 

By use case:

• Open APIs: publicly available APIs that anyone can use to access a company’s data
• Internal APIs: APIs used within a company/organization to communicate information between internal apps
• Partner APIs: APIs designed specifically for third-party developers/partners, and are more limited in access

By protocols:

• REST API: a widely used architecture for building web services using HTTP methods like GET, POST, PUT, and DELETE format to interact with data resources. REST APIs typically return data in JSON or XML format
• SOAP API: a messaging protocol used to exchange structured data between web services. SOAP APIs use the XML format for data exchange, and they typically require more bandwidth and processing power than REST APIs. SOAP APIs support more advanced features like transaction, security, and reliability
• GraphQL API: a query language for APIs that was developed by Facebook. GraphQL APIs allow developers to retrieve only the data they need, using a single query. This can result in more efficient data retrieval and reduced network traffic. Learn more about GraphQL testing.
• Webhook API: a way to send real-time data from one application to another. Webhook APIs use a simple HTTP POST request to send data to a URL specified by the recipient application. The recipient application can then take action on the data in real-time. Webhook APIs are often used for event-driven applications, such as chatbots or notification systems.

10 API Examples of Popular Apps

1. Twitter API

Twitter provides APIs for developers to build apps that interact with its platform. Businesses can use the Twitter Ads API to create and manage ad campaigns, target specific audiences, and track their performance in real time, making it a powerful tool for advertising. 

For example, social media marketing management tools like Buffer allows users to schedule their Twitter marketing calendar, and they must use Twitter APIs to extract analytics from Twitter for their users. Below is the Buffer dashboard with important Twitter metrics such as tweets, replies, retweets, clicks, and more.
 

Source: Backlinko
 

Another interesting API is the Twitter Direct Message API. The Twitter Direct Message API lets developers create chatbots to automate responses to DMs. Companies can use it for tasks like customer support, helping users quickly get answers or resolve issues through Twitter messages.

2. ChatGPT API

ChatGPT stands out because it can hold realistic, human-like conversations. Unlike traditional chatbots with fixed responses, it uses advanced AI to adapt to each user's style and preferences. 

Companies often use the ChatGPT API to create custom chatbots for their platforms or websites. These bots can be trained to answer specific questions about the company’s products and services. For example, here's a guide to build your own AI chatbot with Python. 

There have been many emerging AI-powered Content Writing assistants powered by ChatGPT like this plugin for Wordpress, which leverages the ChatGPT API to bring the chatbot’s powerful functionalities onto your Wordpress backend, allowing you to create content within a few seconds.

3. Google Map API

The Google Maps API lets developers add maps to websites or apps. To use it, developers need a unique API key for authentication and tracking. 

With the Google Maps JavaScript API, developers can customize maps with features like markers, info windows, and overlays, allowing users to interact directly with the map on the site. Common uses include location-based services, such as tracking deliveries or service providers in real-time, helping customers monitor progress and estimate arrival times. 

For example, here is an Address Verification window at a local pizza shop. As you type in your address and click Find Me, the address will be sent to Google Map via the Google Map API. Google Map will return the exact location for the pizza shop so that the delivery driver knows where to bring the pizzas to.
 

4. Discord API

Discord is a free platform for gamers, where users can join "servers" to chat about specific topics or games. The Discord API lets developers create bots or add features to their apps using Discord's data and services. 

Using the REST API, developers can access user data like profile photos and usernames by sending HTTP requests. This acts as a bridge, allowing external or Discord-based apps to interact with Discord's servers.

5. GitHub API

The GitHub API lets developers use code to manage GitHub tasks like creating, updating, or deleting repositories, files, and issues. It automates actions and integrates GitHub with other tools, saving time and reducing errors. 

For example, a developer can use the API to automatically create a repository and add collaborators when starting a new project in a management tool.

6. PayPal API

Paypal is one of the most popular payment service providers, and its API not only simplifies the payment process but also makes transactions extra secure.
 

You’ll be able to find Paypal checkout portal on almost any popular eCommerce website. Simply click on the Paypal Checkout button and you’ll be redirected to PayPal, where you can complete the transaction immediately. 

Your debit/credit card information is registered with Paypal, but Paypal doesn’t share this information through their API.

7. eCommerce API

Shopify is an eCommerce platform that allows small businesses to create and manage their online stores with ease. However, sometimes businesses do require custom solutions that go beyond what Shopify provides. This is where Shopify APIs come in. 

Developers can use the APIs to build custom storefronts, add new features and functionality, integrate with third-party apps, payment gateways, and shipping providers, as well as automate various aspects of the eCommerce process. 

8. YouTube API

YouTube offers an API for any developers wanting to interact with the videos on their platform. The most popular use case is video integration. YouTube API allows you to embed a video straight on your platform. 

For example, a news website could use the YouTube API to embed videos related to a particular news story, or a fitness app could use the API to add workout videos to its library. The YouTube API allows developers to customize the video player's size, playback quality, and other settings to match their application's design and functionality.

Not just that, you can even leverage the YouTube API for data analysis. Developers can extract data about videos, channels, and playlists, such as view counts, likes, comments, and subscribers. 

For example, there is a huge dataset on Kaggle called YouTube Faces With Facial Keypoints containing celebrities facial feature data. This 17GB dataset can be used for facial recognition analysis. 

9. Instagram API

Instagram API is similar to Twitter API, which allows businesses and shop owners to expand its native capabilities as a social media platform. 

Shop owners may want to connect their Instagram feeds with their website so users can have a more holistic view of their shop. Visitors can view the comments and interactions on the Instagram posts, which would have been impossible without the Instagram API. 
 

Likewise, visitors on the Instagram page can purchase the products they want directly from Instagram. The order data will be transferred to the website backend for order fulfillment. 

10. Slack API

Slack is a cloud-based communication and collaboration platform that enables teams to communicate effectively and work together remotely. 

From a technical perspective, the Slack API is quite similar to the Discord API as developers can use Slack API to build custom bots that can automate repetitive tasks or provide specific information to Slack users. For example, a team can build a bot that fetches weather information for a specific location or a bot that sends reminders for upcoming deadlines.
 

Another cool thing to do with Slack API is enabling cross-platform messages to Microsoft Teams. If your team uses both platforms, you can use the Slack API to send and receive DMs and channel messages cross-platform. You can create a Slackbot to automate anything you want yourself: make a document, find an email address, or start a call.
 

What is API Testing?

APIs are the backbone of digital interactions. However, APIs don’t always work correctly. In such a complicated ecosystem, APIs may fail, retrieving the wrong data, losing data, corrupting data, or worse, leading to system failure. It is when developers need API testing to prevent such issues from happening. 
 

If you have an upcoming software interview, you need to know how to do API testing. Below is a quick guide to API testing:
 

1. Identify the API endpoints: these are the URLs through which your application communicates with the API.
2. Determine the API method and parameters: API method includes GET, POST, PUT, DELETE and the parameters (query parameters, path parameters, header parameters, and body parameters)  required for the API call.
3. Create test cases: Create test cases that cover different scenarios, such as valid input, invalid input, and edge cases. You can either use Selenium to test it (which requires Java skills or a low-code automation testing tool like Katalon)
4. Set up the test environment
5. Execute the test cases

Read More: What is API Testing? A Complete Guide