Application programming interfaces (APIs) are sets of rules that allow two different programs or machines to “talk” to each other, exchanging information and improving the functionality of each. But how exactly do APIs work, and what are they used for? What are some of the key considerations developers keep in mind when creating and implementing APIs?
The Basics of APIs
Let’s start with the basics of how APIs work. An API defines functionalities that work independently from the implementations at each end of the conversation. Those implementations and definitions can vary without affecting the other. You can think of the API as providing the building blocks for development when trying to make two different applications work together.
A great way to think about an API is like a waiter at a restaurant. You review the menu and choose which plate of food you want; the kitchen has the power to prepare this food, but they’re used to a specific type of shorthand that differs from what the core menu states. The waiter serves as the API in this scenario; their job is to understand what you want to order, then provide the shorthand necessary for the kitchen to prepare it. They’re also responsible for delivering your meal once it’s complete.
Types of APIs
APIs can be used for almost any type of application. Most commonly, they’re used to draw data from one app (or a specific source) and make it available to another app. For example, with a stock quote API, you can easily pull real-time data from the stock market. If you have a financial app where users can make important financial decisions, this is critical; it allows consumers to see stock prices change in real-time before committing their decision.
APIs themselves can be designed and developed in many different ways. For example, APIs can be programmed in different languages, like Java. There are both program-centric APIs and web APIs—like the Simple Object Access Protocol (SOAP). There are tens of thousands of public APIs designed to make it easier for developers to work (and to make information more readily available), and even more APIs held privately.
The Advantages of APIs
So why do we use APIs? There are several advantages that APIs introduce:
· Functionality abstraction. In some ways, APIs function as a kind of translator. In other ways, they function as a simplification function. In any case, trying to directly program two different apps in a way that allows them to communicate with each other is incredibly difficult; an API attempts to make the data from one app much more abstract and accessible.
· Development speed. In line with this, APIs allow for much faster development cycles, especially if you’re developing custom functionality for a specific app. Rather than having to manually hard code the inner mechanisms of a specific interaction, developers can use the API as a shortcut; this API gives them what they need immediately, allowing them to get the functionality they want with a few short lines of code.
· Widespread accessibility. For many companies, releasing an API for an app allows it to be accessed and configured by thousands of people simultaneously. Rather than handling dozens, or even hundreds of technical requests from developers trying to modify or draw data from your app, you can hand them a simple, understandable API and be done with it.
· Customization potential. APIs often allow developers to customize or extend the functionality of any app. Once the API is available, it can be used in almost unlimited creative ways. Many organizations have used this to their advantage to create perfect-fit products for their teams.
· Regular updates. In most cases, APIs also receive regular updates. When an app changes, or when an API vulnerability is detected, developers must update the API and submit that release. This can occasionally cause headaches for developers who are already using those APIs, but it’s ultimately for the best.
The Downsides of APIs
So are there any downsides to using APIs? The only major factor to consider here is security. APIs function almost like a portal between two apps, so they make it possible to use a vulnerability in one app to exploit another—and occasionally, they introduce new vulnerabilities of their own. Thankfully, security-conscious developers can nix these problems before they become “real” problems.
APIs remain some of the most important development tools we have, and will likely remain that way for the foreseeable future. If you’re an aspiring developer, you can count on APIs opening the door to functionalities that might otherwise be impossible. And if you’re just a consumer interested in knowing more about how your most commonly used apps work together, you can walk away with more confidence in your understanding.