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SOAP and REST Communication on IBM i using RPG API Express

RPG API Express: Uniting Different Systems

As we continue to explore the transformative ways businesses utilize RPG API Express (RXS), today we present the third and final case study in a 3-study series. So far we’ve looked at the ways Gary Wadhwani (owner of Computer Concepts, Inc. and RPG contractor at the Academy of Nutrition and Dietetics) has developed innovative solutions using RPG API Express. The first study explored how Gary built a bridge between the Academy’s Microsoft SQL Server and their IBM i, while the second gave a view into how Gary used RXS and webhooks in order to monitor document changes in DocuSign. In this study, we will look into how Gary was able to touch two different systems, using both SOAP and REST operations.

Connecting systems

Integrating Microsoft SQL Server with IBM i

Signing e-documents

Using webhooks to monitor document changes

Event management

Verifying membership statuses and streamlining registration

The Challenge

The Academy of Nutrition and Dietetics, a membership institution of dieticians, hosts an annual conference with approximately 10,000 attendees. Managing such an event takes a lot of time and resources; to help with this, the organization uses Cvent, an event management tool. However, when adopting the software, they’ve encountered significant challenges in managing conference registrations and tracking online purchases related to the event. Their end goal in this situation was to get information from Cvent to their Microsoft environment, but how? A comprehensive solution was needed to verify membership statuses for discounts, and streamline the registration process. The answer to these challenges was found in RPG API Express (RXS).


Addressing the complexity of the Academy’s issues, Gary decided to capitalize on the power of the RPG API Express (RXS) and the IBM i. He took a two-pronged approach in creating a solution that streamlined the registration process.

  • Creating the Intermediary Application – Gary first focused on developing an intermediary application on the IBM i that would integrate with the existing registration system, Cvent. This application was designed to fill the gap between Cvent and the membership database, allowing for efficient communication between the two.
Graphic showing RPG API Express acting as a bridge between systems
  • Communicating via SOAP and REST – To achieve this, Gary took advantage of Simple Object Access Protocol (SOAP), a messaging protocol that allows programs running on disparate operating systems to communicate with each other. By utilizing SOAP, the application was able to retrieve membership information from the Microsoft platform (per the platform’s own requirements). After successfully obtaining the membership status, Gary’s RXS program then communicated the data back to Cvent using Representational State Transfer (REST), another standard software architectural style used for API communication.

Graphic showing RPG API Express acting as a bridge with connections

Combining SOAP and REST in the intermediary application ensured accurate verification of membership status. With it, members received the appropriate discounts for the conference, helping keep the people that attend the conference happy – and both Gary and the Academy were kept happy.


Gary significantly transformed the way the Academy could communicate with APIs – by building with RXS, he was able to customize a solution exactly to their needs. After all, RXS is a toolkit designed to let you build APIs from scratch. Here’s what he accomplished through building with Cvent:

  • Streamlined registration process: By integrating RPG API Express with Cvent, Gary improved the conference registration process. Now, the Academy is able to verify membership statuses and apply accurate discounts, streamlining the overall experience for attendees.
  • Demonstrated flexibility of RXS: Gary has shown firsthand that RPG API Express is a flexible tool capable of communicating with multiple architectural styles. Beyond the initial simplified API communication, Gary has developed with RXS using webhooks.

Gary’s solutions not only addressed the immediate challenges faced by the Academy but also provided valuable insights into the potential capabilities and advantages that RXS can offer. The impact of these solutions was not only operational but also strategic, offering a roadmap for the Academy’s future plans to enhance their annual conference management and other processes. RPG API Express has proven itself as something the Academy can build and rely upon.

Future Plans

Expanding on the success of the initial implementation, the Academy has plans to further utilize the capabilities of RXS.

An immediate future plan involves developing an additional feature using RPG API Express and RPG that would enable the system to record and update the membership database with details of donations and additional purchases made during registration. This not only improves the Academy’s revenue management capabilities but also provides a more efficient and convenient platform for attendees to make donations and additional purchases, improving their overall conference experience.

The success of RXS in this context has sparked interest in exploring its potential in other areas of the Academy’s operations as well. As stated by Gary Wadhwani himself,

  • “The application that I’m building is going to be in RPG and RPG API Express, but this time as a webhook. That’s going to be used by the Cvent application. It is kind of off-shooting on what we did last year to pull information about a person registering from that form. This time now we’re going to actually register. We’re going to take that information, and go back to that form. So that gives you an idea of what we still do with RXS.”
Snapshot of the Academy's strategic roadmap
Implement real-time communication between their IBM i database and the Microsoft SQL database
Connect Cvent to their Microsoft environment with RPG API Express
Update the membership database with details of donations and additional purchases
Connect with Cvent via webhooks to pull registration information


We’re the lucky ones to have a customer like Gary. He’s worked closely with our team, and to see him use RXS with such ingenuity is nothing short of exciting. He verifies what we’ve been expecting all along – that RPG API Express is a tried and true solution for helping the specific set of people that we all know and love: RPG developers. Businesses run and grow based on the success of their operations, and we are glad to be a big part of it.

Try RPG API Express free
Get a fully featured 30-day trial of RPG API Express and free proof of concept.

If you would like to try RPG API Express for yourself, we strongly recommend trying out a free 30-day trial and proof of concept. In essence, we will build a solution tailored to your needs. For instance, if you have an API you want to connect to, simply let us know, and we will build you an RPG program demonstrating exactly how to do that. There’s no gimmick, RXS has been around for over 15 years, and is the preferred solution for RPG developers aiming to build APIs on their IBM i.

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