Even if you’ve never heard of APIs, you’ve almost certainly used them. Every time you use Facebook to log in to an app, look up the weather forecast, or even copy and paste text between two different programs, an API makes it all possible.

But what exactly is an API? What’s the difference between an open API and other types of API? Most importantly, how can you use open APIs to improve the product or service you offer?

API definition


API stands for Application Programming Interface. A simple API definition is that it’s the interface between multiple software applications, one that allows them to communicate with each other and exchange data.

To illustrate how an API works, let’s go back to one of the API examples we’ve already mentioned. When you use Facebook to log in to a new app, the app sends a request to Facebook, asking them to confirm your details and supply any relevant information to improve your experience. Facebook’s API handles that request, securely exchanging the details.

Think of an API meaning an agreement between two parties. The API outlines what details and features can be requested, how to make that request, and ensures it all happens smoothly for a positive user experience.

Open API, public API, API definition, what is an open api, what is a public api

APIs are commonly categorized by their availability. For example, you could have a private/closed API, which would be usually created in-house exclusively for the use of a specific company’s employees. You could also have a partner API, where the API is made available to a company’s partners and customers. However, there are also public APIs (also known as open APIs) that anyone can take advantage of.

What is an open/public API?

Open API

An open API is commonly used to refer to an API that’s publicly available. That means anyone can use it, either to extend the functionality of their products or to create an entirely new solution

However, it shouldn’t be confused with the OpenAPI specification, which is a guideline for how to structure and document an API.  

Why would a company make their API publicly available? For one, it’s a great way of building brand awareness. The open APIs created by companies like Google, Slack and PayPal have enabled them to reach far more people than they could have ever hoped to on their own. Additionally, public APIs have helped accelerate innovation across countless industries. Rather than every app developer having to come up with their own code for search, communication or payment processing, they can use tried and tested APIs to take care of those secondary tasks while they focus on new ideas.

Note that there are also different specifications and frameworks that can be used to create an open API.


One popular example is REST, an acronym for REpresentational State Transfer. Rest is a set of rules that govern how the API looks, part of which includes the use of hypertext to exchange information.

This style of API is associated with greater flexibility and freedom as it isn’t constrained to returning just one format. Instead, Rest APIs have six guiding principles, including being stateless and having a uniform interface. Rest APIs are used by many well-known technology companies, such as Amazon and Netflix.

Benefits of using open Rest APIs in your business

There are lots of benefits to using an open Rest API, perhaps most significantly in simplifying app development. Rather than having to reinvent the wheel or spend excessive time coding their own interface, companies can take advantage of the easy integration that’s possible with an open Rest API. As well as making the process easier, an API allows development teams to focus their efforts on their own key differentiators and unique selling points (USPs).

FinTech startup Azimo found themselves in need of a way to effectively deal with a high volume of incoming calls. As they had a very clear picture of how they wanted their voice support to be, they decided to use SnapCall’s Rest API to build their own unique calling experience. As a result, they were able to continuously reshape their support to fit in with their changing priorities and customer behavior, rather than being tied to a rigid off-the-shelf solution or having to code their own.

Using the SnapCall public Rest API

For most businesses, SnapCall’s plug-and-play voice communication solution will be sufficient as it is. You don’t need any special tech knowledge or an in-house development team to use SnapCall as it is and start offering calls from your website, mobile application, or chat window.

However, companies that are looking to create their own call solution, with full control over the user experience, interface, and general functionality can benefit from our public Rest API. Our open API allows businesses with the necessary development resources to take full advantage of SnapCall’s features while building a solution that’s specific to their brand and tailored to their customer’s journey.

For example, our API allows you to completely redesign your call flow:

  • Choose when the call button is displayed based on your chosen triggers
  • Choose what the call button looks like with a fully customizable design
  • Choose what data is transferred during calls and used in reports
  • Create your own custom routing, either through SnapCall or a traditional voice solution
  • Create your own agent console, with an interface tailored to their requirements

Similarly, our API can be used to quickly and seamlessly integrate our click-to-call functionality directly within the chat window. This has been successfully implemented with chat solutions including LiveChat, Intercom, Zendesk Chat, Messaging and Sunshine Conversations.


Open APIs are the backbone of modern app development, created and used by companies of all sizes and covering countless different use cases. By enabling apps to communicate and share data, they help businesses speed up development and innovate within their niche. Whether you’re looking to build a new piece of software or integrate an existing solution with your platform, using a public API can give you a head start.

Are you looking to build your own calling solution? Looking for a way to integrate voice into your chat platform?

Let us help you achieve this with the SnapCall API. SnapCall - embedded voice, video calls and screen sharing right inside the chat window with your customer.

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