Creating an IBM z/OS Connect API requester project and z/OS application

Use this tutorial to understand how to call an OpenAPI 3.0 API endpoint from your z/OS applications.

About this tutorial

zosConnect-3.0 Applies to zosConnect-3.0.

Started task Applies to z/OS Connect Servers run by using a z/OS started task procedure.

This tutorial is a complete implementation that includes both the API endpoint and the z/OS applications that are used to call it. The components that are covered in this tutorial are.

  • The z/OS applications and how they use the Host API to call the API endpoint application and how they process the response.
  • The z/OS Connect Server and how the WAR file is deployed to allow the call from the z/OS applications to the API endpoint application and back.
  • The API endpoint application that is called plus how that application is built and deployed.
  • The OpenAPI 3.0 document that describes the endpoint application and how it is used to build an API WAR file.

Diagram showing how the API requester connects IBM z/OS Connect to the z/OS address space so that z/OS applications can call an API.

This tutorial uses the concept of an IBM Redbooks information repository to show how z/OS Connect API requester can be used to call OpenAPI 3.0 defined APIs.

Completing this tutorial helps you understand:
  • How to write z/OS applications to call an API endpoint.
  • How to process multiple HTTP response codes.
  • How to manage dynamic length arrays described by an OpenAPI 3.0 document.

The industry standard build automation Gradle is used to build the API endpoint application WAR file and the z/OS Connect API requester WAR file.

Note: Security is not enabled for this tutorial. If security is enabled for your z/OS applications, then reference the Securing IBM z/OS Connect resources for zosConnect-3.0 section of the z/OS Connect documentation.