Application Programming Interface

What is an API?

APIs, application programming interfaces, are used to allow software applications to communicate. This unique interface dictates requests and responses to and from different systems to allow for the exchange of data. Each letter in the acronym API has an important meaning.

Interface: Let’s start with the “I” because that will help to better contextualize the term in question. An interface, in short, is how individuals interact with a computer. As an interface, an API is a way to interact with the underlying program or software for which the API was created. We work in interfaces everyday. In fact, you are currently viewing this article through an interface – a graphical user interface (GUI or UI). Developers spend much of their time coding in a different interface – a command line interface (CLI). When you talk to Siri you are leveraging yet another interface – a natural language interface (NLI). We could go on here, but I think you get the point.

An API is a unique interface in which to interact with software.

Application: APIs are specific to an application, service, or function. The application is what an end user (whether that be a person or another application) is trying to communicate with by way of an interface. The same way you are interacting with this UI to reach Aloi or how you would be interacting with the bank when using an ATM.

APIs are specific to an application.

Programming: This speaks to the function of the interface. The same way UIs are intended for everyday consumers and CLIs are intended for developers, APIs are intended for the communication among and between different programs, pieces of software, or applications. While humans interact with APIs to develop and connect them, the end users of an API are other applications.

Who works with APIs?

In short, everyone works with APIs. But an answer as simple as that would be as helpful as answering “what color is the sky?”

Developers build the interface; just like they build UIs. Software engineers also work with APIs to connect them. Once an API is built and published, it can interact with other APIs through the internet. Through the connection of APIs, the software can communicate with one another.

Developers build, connect, and manage APIs.

Software applications consume and request data from APIs.

Why are APIs used?

APIs enable apps to utilize data or functionality of another software.

A great way to think about an API is to put it in the context of your own interactions with applications. When you are using an application, say Google, you have a prescribed method of interacting with it. You know to type the search criteria into the search bar and press “enter” or click the button that says “Google search.”

You are also intimately familiar with the format of the data that will be returned to you: at the top of the page you will often see a few sponsored results that are paid for, and likely a summary about a place or person in a box to the upper right if that is the nature of your search. The point is this: as a user of Google’s UI, you have an intuitive understanding of how the system is requesting data and responding. In the event that you do something outside the parameters of the app’s expectations, you will receive an error message explaining what went wrong.

An API is no different. In fact, Google’s search application has an API. Through the application programming interface, the same parameters are upheld in a different format to achieve an executed search through Google’s search application. While the UI is leveraged by internet users, the API is leveraged by other applications that want to utilize a Google Search natively.

What does an API look like?

API endpoints are the URLs that an API user communicates with in order to access a particular action in an application.

For example, in looking at Insightly’s API documentation you can see that in order to access information on a particular contact the action would be “GET contacts.”

In order to get information on a contact, the API call would go to the following endpoint:

https://api.insightly.com/v3.1/Contacts

To execute the GET contact API call for a contact with the ID 294272126, you would call the API as follows:

https://api.insightly.com/v3.1/Contacts/294272126

The Insightly API would return the following:

… the list goes on, but hopefully you get the picture. You effectively just walked through a successful action in order to request data from the Insightly API.

Same data. Different interface.

When are APIs used?

All the time. But seriously.

Even in the page you are reading, the front-end UI is calling an underlying API to make this content and your digital experience come to life. In an increasingly complex yet technologically advanced era, computing has been broken down into its smallest parts to create the strongest outcome. In a cloud-based environment dozens or hundreds of applications are working together to bring a refined technology product to life.

Put another way, APIs are the engine that connect different applications that do different things. “Sign in through Google” is a Google authentication API that talks to the hosting site’s API. App store apps connect respective application APIs and call a bespoke API to bring a certain outcome to life. Your SalesForce integration with HubSpot is two APIs talking to each other.

APIs allow for software communication. They are used all the time, by everyone.

How should I use this site?

At Aloi, we believe in community. And we are proud to be part of the API community. Our name (pronounced `a, loi or al-loy) was inspired by alloy— a metal created by a combination of two or more elements to produce greater overall strength. Aloi is similar. We are a destination for business users and developers alike to share knowledge, community and integrations that will make for a stronger whole.

In the associated resources, you will find a guide to better understanding APIs and integrations no matter what your technical know-how. Take a spin and join us on our journey to create a more connected world.

If you are ready to start integrating, check out our platform. We have simplified the ways in which software connects. We are creating the worlds’ largest community of people, software, and connectors. Join us!