5 Things Every Developer Should Know About Open Banking

iStock / iStock

Can banking make a developer’s life easier? Today, open banking is the up-and-coming tech movement positioned to spark innovation within the field of financial services, putting a whole new world of financial services at users’ fingertips.

The possibilities of exciting new user experiences, frictionless payments, and smart handling of financial data offer promising opportunities to create new products. Whether you’re a product manager or a developer, here are a few handy things that can help inspire your next project.


“Open banking” sounds exciting, but what exactly is it? Put simply, it’s the push for banks to allow secure data sharing with third-party developers via interfaces known as APIs, or application programming interfaces. APIs have long been used as ways for different software and servers to communicate and exchange functions. Open banking is the push for banks to open their APIs, thus making financial information available to developers.

What does this openness mean for your business? Imagine you’re building an incredible e-commerce site. Wouldn’t it be fantastic if you could let shoppers pay for their purchases using credit card rewards points? With an API from Citi Open Banking, you can easily add that functionality to your store. Customers will benefit from the ability to seamlessly spend their points, and they might even be more likely to make a purchase since you’ve given them that power.


On top of user-facing benefits like enabling customers to pay with points, APIs are a huge boon for fintech developers, because they offer businesses a “way to integrate a technological brick or a set of data in their application without the need to build it themselves,” explains lead API economist Mehdi Medjaoui of the API Academy. “Banks can open APIs that enable fintech companies to access customers’ payment history, initiate payment, or open a credit line, for example.”

In other words, the next time you need to add financial functionality to a project, you may be able to skip the long hours of painstaking coding by utilizing a tested, supported API that can get the job done.


Developers and product managers have to constantly think about the needs of their customers, but when it comes to open banking APIs, the situation is reversed—the developer becomes the customer. As banks make their APIs available, developers will jump at the opportunity to access new data and functionality, especially if these APIs fulfill specific needs. Since APIs are supposed to be reliable, time-saving tools, usability is as important as usefulness.

That’s good news for developers, because it means banks are motivated to make effective APIs that can be easily implemented. “If developers have a choice between two APIs that do similar things, they will pick the one that they can understand and use quickly,” says API Academy vice president Matthew McLarty.

In other words, the makers of APIs are actively looking to make your life as a developer easier in order to drive adoption of their APIs. This means that developers will ultimately receive a flexible API that has their needs in mind, preferably accompanied by documentation that explains how API calls can help a consumer complete a task.


Support is crucial, especially for self-service APIs where users are left to their own devices when integrating and tinkering with APIs. Some good support functions to look out for include a forum where new versions and updates are clearly communicated, a blog where users can share knowledge, or a 24/7 helpdesk. Some support naturally comes from the communities of developers that coalesce around APIs: An “active community of users that are able to collaborate and solve their own issues through a web forum or other means” is a good sign, says McLarty.


“When you integrate an API, you integrate the world behind it,” notes Medjaoui. APIs can be incredibly useful for developers, but it’s also important that developers think about how APIs serve their purposes and fit into the larger product they’re building. Like any tool, it’s important to pick the right API for the job.

“Developers should analyze their business goals and business models and determine what product features are their differentiators, and what features are just enablers,” cautions McLarty. “I would recommend using APIs for the enabling features, but keeping the differentiators in house.”

Here’s a useful line of thinking, suggests Medjaoui: “A great search experience for my e-commerce website would be a plus, but since it’s not critical in my value proposition, let's use an API for that.” By using an API for that sort of functionality, you can speed up your project’s timeline and open up resources for the unique aspects of your product.

One more thing developers should know about open banking: Citi Open Banking offers a whole suite of global APIs that can help bring your next project to life. Learn more at https://sandbox.developerhub.citi.com/.