This tool allows RPG programmers to create and publish RESTful web services on IBM i (AS400). Therefore applications written for Google App Engine (or for any other application server in public or private cloud) could call these web services and interact with IBM i programs.

General description

The product allows you to:

  • Create RPG programs or use existing RPG programs and publish them as RESTful WebServices on IBM i (AS400).

  • Reuse existing 5250 transactions and publish them as RESTful WebServices on IBM i (AS400).

Applications written for Google App Engine, WebSphere Application Server (or for any other application server in public or private clouds) could call these WebServices and interact with IBM i programs.

All the WebServices realized by WDT4i can be installed on any application server, even if it is external to the AS400 system.

However in the WDT4i environment a Tomcat application server is furnished in PASE environment too.


WDT4i goals:

  • Offer to RPG programmers an AS400 development environment which does not need external software.

  • Reduce to a minimum the skills needed to create distributed applications (WebService,RESTful, etc): the RPG programmers task is to furnish new or existing business objects.

  • Get rid of 5250 software rewriting cost in order to separate the business logic from the presentation logic.

  • Reuse a 5250 transaction without having its sources.

  • Maintain existing 5250 SW stability.

  • Exploit all the application codes which are already in a 5250 program.

  • Add new I/O information to 5250 transactions which will be reused in distributed architectures, without having to modify the 5250 application.

  • Extract only a subset of functions offered by a 5250 program, and not the entire program.


  • Installation
    A library to be installed on AS400.

  • Training
    Skills different from RPG are not required.

  • Transactions managed by who knows them best

  • Furnish new data in the 5250 screens
    Through the creation of a User Exit the programmer can add new output fields without having to modify the 5250 program.

  • Limit the information to be published
    The programmer decides which information to make public and which to hide; which fields have to receive a default and which have to be called from the outside.

  • Execution speed
    The 5250 program reused with this technology exploits the batch potentials of the AS400 system.

  • Process reuse
    An AS400 process can be reused unlimited times in order to respond to the WebServices requests. Once the request is completed the 5250 program positions itself in the starting screen and waits for the next request. In this way the AS400 does not have to recreate a Job, but reactivates an existing one.

  • Complete division by skills
    Those who take part in the project (RPG programmers on one side and Java php .NET etc. programmers on the other one) remain independent in the management of their respective platforms and competencies. The joining link is the WebServices standard.