How Does an API Work?

To understand how APIs work, we need to know what they are used for and why. APIs are used to communicate between different technology applications, to allow one app permission to use a function of another.

APIs let one app talk to another by sending strictly constrained function calls, a type of message that requests a certain action and to which the other app will respond, also via the API.

API Example

An example of this Application Programming Interface in use is in apps that use APIs for Google Maps. Imagine you have a food delivery app that needs to know your geolocation to send your dinner to your front door. Instead of using its own location services, world map and route planner, it’s much easier for the app to use the tech capabilities of another, pre-existing service like Google Maps.

The app sends a request, in the form of a call function, to the Google server’s API with an instruction of the type “Use location services and Wayfinder planning”. The API translates this into a command to Google Maps, which duly sends the information back to the food delivery app.

API vs. SDK vs. EDI

Using an API is only one way to communicate between disparate internal and external applications. Other popular and common tech solutions to process requests from other apps (before APIs were invented) include the Software Development Kit (SDK) and Electronic Data Interchange (EDI).

• SDK: A Software Development Kit is a set of tools that is used to create a software program that is specifically coded to process system calls from other platforms. SDK is a broader term than API as it can encompass a whole range of documentation, samples, tools and, yes, even interfaces such as an API
• A good reason to use an SDK rather than directly using an API is that SDKs are an out-of-the-box solution that can be easily coded by almost anyone for a variety of purposes, whereas APIs have a more specific, narrow function that requires intense and expert coding by specialist developers, but which may be more powerful depending on the complexity of the system call required. 
• EDI: An Electronic Data Interchange is a simpler concept that involves transferring information from an application in one business organization to another without human intervention. It’s mostly used for the unilateral sending of documents that would otherwise be paper-based, such as sending invoices and purchase orders to business partners.
• EDIs cannot be used to replace APIs because they serve a different purpose; EDIs are documents that are automatically moved from a sender to a recipient using point-to-point connections or a Value Added Network, while APIs call from one application to another to perform a certain task.

API Gateway for Microservices

An API gateway is a management tool for APIs that works like a command-and-control center, where API creation and management is done. Using an API gateway, you can code, publish, send and monitor APIs, plus manage incoming requests from external APIs.

An API gateway is required in microservices because it helps a company that uses various internal and third-party applications to have all the commands and requests between each siloed tech in their stack running through a single, central location. It also helps the company’s programmers to have a base on which to code the APIs. APIs can be coded with Python, PHP, R, JavaScript, Golang, SQL and JSON, but it’s also possible to build APIs without coding using readymade tools.

The most popular cloud services all have their own API gateway, including Amazon Web Services (AWS), Microsoft Azure, Red Hat and Google Cloud Platform (GCP).

The best API gateway for your microservices will depend on what specific microservice technologies are in your company’s stack and how you will use them, so talk to your cloud service provider to see what they recommend will fit in best with your existing applications.

5 Reasons Why CFOs and Management Love APIs

When trying to implement a digital transformation project for your company, it may be wise to take an API-first approach, which means designing the new technology stack from the point of view of microservices interacting via APIs. These are the advantages of using an API-first design for digital transformation:

Only Buy What You Need, When You Need It

Since APIs are used to communicate between the different microservices and applications that work together to form an organization’s operating system, you only have to update and reprogram them as and when you switch out your microservices for new and improved ones.

This, in turn, means you don’t need to bet big on one new monolith technology stack, but can build up your own customized software network piece by piece, at a pace and with a budget that suits you.

“MACH technologies [Microservices, APIs, Cloud, Headless] support a composable enterprise in which every component is pluggable, scalable, replaceable, and can be continuously improved through agile development to meet evolving business requirements.”

Shorter Implementation Times

As well as allowing you to break down a digital transformation project into smaller chunks, APIs make each individual phase of the digital transformation shorter and cheaper. As a result of this staggered form of digital transformation, the time it takes to finish any given stage of a project based on microservices and an API-first approach is much shorter than if you were to attempt to restructure the whole company’s tech stack at once.

In this way, the quick turnaround times and philosophy of Continuous Integration and Continuous Development present in API-based projects makes them an absolute dream for your DevOps department. And of course, shorter implementation times mean less money you have to spend on planning and deployment, so your CFO is happy.

APIs Never Grow Old

Remember, the API is not the end goal of your digital transformation; it’s just a means to get there. You may want to plug a flexible POS system into your online store. You may want to add a Customer Data Platform to segment target audiences into individual users. Whatever kind of new application you wish to implement for your business, you know that it may become outdated within 5 years and you’ll need to replace it with the next big thing.

The good thing about APIs, then, is that they will allow you to swap out old apps for new ones over and again, to keep you competitive in the market indefinitely. They’re not just one more tech to add to your stack that will need replacing in a few years; they make doing that easier for the rest of your tech. They’re not just another fancy, flash-in-the-pan invention; they’re an investment in the future of your company.

Minimise Risk of Tech Stack Changes

With an API-based digital transformation, it’s not only cheaper and faster to make ongoing changes to your organization, but it also minimizes the risk of changing important parts of your operating software. By going slowly, one app at a time, your Operations team can assess whether the change in applications was successful, or needs to be rolled back.

This is especially effective if you use an API gateway because they let you select how much live web traffic is shifted to a particular environment, whether the old or the new, so you can perform Canary and Blue-Green deployments for a truly risk-managed release. That way, if the worst does happen and something goes wrong that needs to be reversed, the changes are not irreparable and it is not so costly to do so.

Mix and Match In-House Tech with As-a-Service Providers

Finally, C-suite executives are finding that APIs allow them much more flexibility with regards to which applications they handle in-house and which ones they want to outsource to third-party “as-a-service” providers. Unless you’re Amazon or Google, it’s unfeasible to expect to own and control every single siloed technology that your company uses. But there are some apps that will be specific to your industry, or that you have developed yourself and which place you ahead of the competition and that you have to host in-company.

APIs give organizations much more freedom to pick and choose which apps they develop and run in-house, and for which ones they delegate responsibility to managed service providers. And, as ever, this configuration can be customized and changed at the drop of a hat to give your CEO, CIO and CTO maximum control over business processes, and your CFO peace of mind about the company’s budget!

To learn more about how SmartOSC uses APIs, microservices and other cutting-edge technology to enable brands’ digital transformation, call or write to us and we’ll be happy to chat.