An internal API is an interface that enables access to a company's backend information and application functionality for use by the organization's developers.
The communication between a waiter and the Chef in a restaurant.
When you are in a restaurant, a waiter must communicate to the Chef what your order is. In order to facilitate that communication, they may submit the order on an internal system or just rip the piece of paper off and stick it up on the Chef’s queue.
However the waiter communicates this, the method of communication is performed by the waiter, an employee of the restaurant, to the Chef, an employee of the restaurant.
An Internal API allows developers at a company to access information from their company.
It's one thing to know what a term means, but that is worthless if you don't know why you should know what an internal API is in the first place. Let's break down the importance of this tech term based on two high level categories. We'll walk through an explanation as well as provide a score, 1-10, that shows you how much you should care about internal APIs.
The first will be if you do not have a product yet. This means that you don't have a physical product. Maybe you're in the ideation phase, or maybe you're almost ready to start development. Whichever it is, we'll get into why internal APIs are important and why you should or shouldn't care about it if you do not have a product.
As a founder, an Internal API is not too relevant if you don’t have a product yet. You should learn about the functionality of an API, but the actual type of APIs is more relevant once you actually have a product and need to understand how your site should function most effectively.
The second category is if you do have a live product. Maybe you just launched your business or maybe it's been live for years and you're continuing to improve its quality. Regardless of the scenario, if your product is live, an internal API carries a different weight.
As a founder, an Internal API is fairly relevant if your business model requires you to interact, via software, with exclusive partners. For example, if you are Bank of America, then knowing that your application has an internal API to allow ONLY your internal developers to access certain data is very important because it is pivotal to your business model that nobody else can access that data.
So you know what an internal API is, by definition. You know if you should care about it or not depending on your situation as a business/company/product. To dig in deeper, we will walk through some examples so we can make sure you really have a solid grasp on internal APIs.
There are tons of APIs out there, but we'll walk through three specific examples of common internal APIs that are used in the real-world. Since an internal API is one that is only used within an organization, these aren't as common for an every-day consumer to interact with. Regardless, these APIs are still vital to the life of a product and important to understand.
1. Your account information in any application you use
When you log into an application where you have an account and profile, that information has to be stored somewhere. More than likely, your information is stored in the company's database, and when you log into your account, the information will populate on your screen. In order to be populating the proper information when you log in, the application leverages an internal API to access the proper information. This API is only accessible within the organization, meaning nobody outside of the team is able to access your information. The API is able to recognize that you have logged into your account and then communicate to the database that it requires your specific information to populate on the screen. All interactions are occurring within the company and not with any 3rd parties.
2. Ordering food at a fast-food restaurant
When you go to a McDonald's, you place your order and the employee at the counter enters it into the computer system they are using. When they enter this information, it then gets sent to the kitchen and added to the queue to be prepared for you. The kitchen is able to access this information via an internal API. The screens that the kitchen looks at will leverage an internal API to pull the most recent orders placed and populate them on their screen, allowing the cooks to know what to prepare and in what order. Only the kitchen is able to access this information as the API internal, meaning not public facing.
3. A fin-tech startup needs to access its own data to populate metrics for their users
Imagine you are working at a fin-tech startup. The startup requires users to enter information on all of their purchases via credit card and it will then populate a dashboard which shows how efficient you are at leveraging credit card points. In order to show this information on a user's dashboard, the developers at the company first have to pull in the database information for each individual user. In order to access this information in the database, the developers have to leverage an internal API, meaning only a developer (or someone within the company) can access this information.