API is the acronym for Application Programming Interface, which in layman's terms is a way for applications to speak to each other via a software intermediary.

As somebody that uses the internet (which, as you're reading this, we assume you do), you're likely using APIs all the time. So, for example, you're using an API whenever you send an instant message or check the news or the weather.

APIs are the backbone of the modern internet. Despite being around for a long time, the API economy is booming and transforming how services are built, delivered, and consumed.


Whenever you use an application, whether on a phone, tablet, or desktop, that application likely sends data to a server over the internet.

The server, in turn, interprets the data it has retrieved before performing anything it deems necessary (as per its design or use) and sends the data back to your device.

So, for example, if you were to use an API to retrieve a portfolio on our APIs, you would request the information you wanted via a GET request:

curl --request GET \
--url https://api.sandbox.wealthkernel.io/portfolios/portfolioId \  
--header 'Accept-Version: 2021-05-17' \  --header 'Content-Type: application/json'

In response, the system would send back something along the lines of:

    "id": "prt-32q2deogu225ps",
    "accountId": "acc-34itov6w523b7o",
    "clientReference": "5c6759ff36",
    "name": "Savings Portfolio",
    "status": "Active",
    "currency": "GBP",
    "mandate": {
    "type": "NullMandate"
    "createdAt": "2019-10-08T13:55:16.4237925Z"12

Modern APIs and the API Economy

Modern APIs are likely RESTful or REST APIs, which is to say they have been designed using the REST architectural style for networked applications.

While an API is a set of functions and procedures enabling applications to access the features of each other (or for one-way consumption), a REST API is simply APIs following the REST architecture.

REST APIs are developer-friendly, accessible, well-documented (see ours, for example), and are designed for consumption of services for different users and/or audiences.

The API Economy is a term that's risen to prominence in recent years with the rise of platforms like Stripe, Square, and others offering services that were previously software-led, just "over" API instead.

Ready to get started?