Introduction to APIs

Various weather apps can show you your local temperature and weather. But do you know that none of them actually measure the temperature of your locality?

Moreover, when you book an Uber ride, you can see the location of the driver you are assigned to. Throughout the ride as well, you can track your location and check your route. Again, is this mapping service created by Uber?

The answer is no– to both of them. Uber borrows the mapping service from Google Maps while weather apps get their data from weather service providers like Open Weather Map or AccuWeather.

And they do this with the help of APIs– which stand for Application Programming Interfaces…

What are APIs?

IBM (International Business Machines Corporation) defines APIs as “…a set of rules or protocols that enables software applications to communicate with each other to exchange data, features and functionality.”

In our example, Uber uses Google Maps’s API to integrate maps and location tracking into their application, while weather apps use Open Weather Map API or AccuWeather API to get weather updates for you.

In this way, instead of building location or weather services from scratch, APIs enable developers to ‘borrow’ those services from other applications already specializing in them. This saves significant amounts of time and effort while also broadening an app’s or website’s functionality. Because of this, APIs are considered an integral part of modern applications and websites.

How do APIs work?

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API working can be explained as a client-server model. The client (Uber) submits a request to the server (Google Maps) and the server responds to the client with the requested data (maps). However, this is only an overview of the API communication.

The API request is further made up of components that vary with the type of architecture of protocol it is following. The most popular architecture is REST architecture which we will be discussing primarily.

REST API protocol & its working

REST API or RESTful API stands for Representational State Transfer. It uses HTTP (Hyper Text Transfer Protocol) methods which include GET, PUT, POST, etc (more on this later).

The primary feature of REST API communication is statelessness. It means that the server does not store any information about the client and any transaction remains unrelated to its previous transactions.

A RESTful API request includes the following components:

• API endpoint: An endpoint is a specific URL dedicated to specific resources on the server. Based on what resources are required, the client sends the API call to the specific endpoint on the server.
• Method: Every API request includes a method that defines the action the client wants to perform on the resource. REST APIs use HTTP methods like:
  • GET (for retrieving data from a specified resource)
  • POST (for creating a new resource)
  • PUT (for updating the resource with new data)
  • DELETE (for removing a resource)
• Parameters: Let’s say you are ordering food from a food delivery app. The API needs to know certain things to process your request – like what food you want, your address, your name, etc. These details vary from person to person and are sent to the API through parameters. In other words, parameters are the variable elements in a resource. Some common types of parameters include query, header, path, and body
• Request headers: Request headers provide extra details about the API request like the authorization credentials, content type, and information about the client.
• Request body: Request body consists of the actual data of the request. For example, in the last example about the food delivery app, the request body would include the order details like the food items, address, and customer info.

Benefits of using APIs

• As already discussed, APIs help integrate newer capabilities and functionalities into the application or website without the need to create them from scratch. It is done so by sourcing those services from specialized applications.
• APIs also help different services within the same application communicate with each other even if they are built using different languages. This further improves the integrity and functionality of the system.
• API communication is protected by several layers of security. For example, authorization credentials in HTTP headers and statelessness of RESTful APIs. It also protects the privacy of personal users. For instance, when a website asks you if it can access your location or not.
• That said, APIs benefit the business by saving costs and reducing time-to-market for new products and features and benefit users in terms of improved user experience.

Conclusion

APIs are the communication link between services within the same and even different applications. They help companies diversify their software’s capabilities without investing much time or effort while also reducing costs. Moreover, while integrating new features and enhancing customer experience, APIs also take care of security for both, the client application and the user. Thus, APIs have become crucial to the success of modern applications and websites.