Simplifying Access to Legacy Payments Applications

One of the main trends highlighted in our recent article The Top 5 Trends in REST Services relates to payment applications, and in particular, simplifying access to legacy payments applications like BASE24 and Connex, both of which are still very popular on the HPE NonStop platform.

REST services are becoming extensively used in the payments space., which maintains a directory of all public Web APIs, tracks financial API usage in the following diagram, which shows some steep usage increases:


This graph shows two points where growth really took off – 2012, and the period between 2017-2019. The first increase corresponds with a general increase in API usage globally. The second is more interesting, and is related to the usage of open banking APIs. The European Union-driven PSD2 (the revised Payment Service Directive) which had a deadline for implementation of January 2018, and other open banking regulations, are primarily responsible for these increases. Indeed, across the years 2017-2019, there was an average of more than 600 financial APIs added each year.

How can the use of APIs be leveraged by HPE NonStop users?

NuWave offers two HPE NonStop-based products that can help users to take advantage of the growing use of APIs. . LightWave ServerTM allows NonStop payment engines and other applications to be securely and easily exposed as REST-based Web services. LightWave ClientTM allows NonStop applications, including payment applications, to quickly and easily access REST-based Web services outside the NonStop–either within the enterprise or external to the business.

LightWave ServerTM and your payment engine

LightWave ServerTM can work in a variety of different ways to create REST services from your payment engine. Consider the following diagram, which shows LightWave ServerTM integrating HPE NonStop Pathway applications with mobile applications, smart home devices, PCs, and enterprise applications. The external application sends a REST request to LightWaver ServerTM, which translates and passes that request to the backend NonStop application and then relays the reply message back to the requestor.

This example might be a good fit for customers wishing to REST-enable their BASE24 Pathway management screens, for instance. This could allow simplified access for customer service representatives, perhaps by aggregating information from multiple Pathway screens into one modern UI. It could also be used by a homegrown payment application running on NonStop, with LightWave ServerTM presenting an IPM to the in-house application in the format expected by the application. This would allow the payment application’s transactions to be exposed as REST Web services without changes to the application.

BASE24 Classic and BASE24-eps utilize XPNET as their message-oriented middleware (MOM) on NonStop. This means that any REST solution needs to integrate with XPNET to allow REST-enablement of the BASE24/BASE24-eps online transaction path (e.g POS or ATM transactions). XPNET does support Pathsend messages, via its Common Transport Subsystem (CTS) protocol. The CTS Pathway protocols allow XPNET to present itself as a Pathway server, and/or act as a Pathway client and access other Pathway servers. In this way, the LightWave products can integrate with XPNET, and therefore BASE24/BASE24-eps (see diagram below).

Using this approach, any BASE24/BASE24-eps transaction can be REST-enabled, usually without requiring any application changes. LightWave ServerTM handles the REST request and will present the required application message to XPNET via Pathsend, which will process it and forward it onto the correct BASE24 satellite process. This approach could be used, for example, to allow an internet banking application to quickly access a BASE24 transaction, and make that transaction available to the bank’s internet banking users.

LightWave ClientTM and your payment engine

More and more often, payment application users need to incorporate remote services into their payment transactions and capabilities. Consider a rules engine on a different platform within your enterprise that exposes as a REST service the rules for flagging transactions. If your payment engine needs to access those rules as part of its transaction authorization, it could integrate with the rules engine using JSON and REST technology. LightWave ClientTM can facilitate this type of connectivity.

Similarly, LightWave ClientTM also allows payment applications to take advantage of the many thousands of public Web services available, by bringing data from those services back into the online transaction path. Services for currency conversion, for blockchain-style operations, and for stock price lookup are just a tiny sample of the types of services that you could leverage in your enterprise.

The next step in payment integration

API gateways, such as those from MuleSoft and IBM, often play an important part in organizations that process payments. API gateways can normalize, aggregate, and in many other ways coordinate an organization’s Web services. For payment engines running on NonStop, API gateways present an opportunity, but also a challenge. If a transaction or service of the payment engine needs to be made available to the rest of the enterprise through an API gateway, the payment application needs to support a data format that the gateway supports. Legacy protocols, such as those used by many payment engines, are unlikely to be natively supported by an API gateway. By utilizing LightWave ServerTM to REST-enable the payment engine, the application can often be easily integrated with the API gateway, and therefore become a part of the enterprise’s Web service ecosystem.

Another API gateway use case arises when a payment engine needs to incorporate a service provided by an API gateway. Once again, the API gateway will support modern access methods like JSON/REST, but is unlikely to support older legacy formats. LightWave ClientTM can be used to help invoke the services that are accessed via the API gateway and present the results back to the payment engine in a format it can support.


Both LightWave products include a comprehensive list of standard features that ensure your valuable transaction services are as reliable as the rest of your NonStop application infrastructure. They are completely fault tolerant, include support for TMF, and have extensive diagnostic logging. With built-in security features, including TLS, authentication and authorization, and a number of features to provide scalability and high throughput, you can be sure that your services remain up and secure at all times.

Once you take a look at REST, and APIs in general, you’re sure to find numerous ways in which they can help you modernize and open up access to your NonStop-based payment application. Your customers and business partners will likely thank you too!


  • Andrew Price

    Andrew Price has worked on the NonStop for his entire career. He spent most of the 90s as a BASE24 developer at different banks in different countries, then many years at Insession and ACI. He’s also worked at XYPRO and most recently served as NuWave Technologies’ Chief Operating Officer. He has extensive experience in most aspects of NonStop software development and sales, having been a coder, product manager, sales support technician, and engineering manager. He has been with Infrasoft since January 2020 where he is Director of Business Operations. You can connect with him at or on Twitter @andrewgprice

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