Lozen’s Support for OpenAPI

Lozen offers several connectors to enable mainframe data access to a broad range of applications.  In this blog, we explain two of these in more detail: 

  • The Lozen OpenAPI Connector, which makes it possible to access mainframe data, such as VSAM files, from any OpenAPI application (such as Microsoft Azure Logic Apps, Boomi, TIBCO, and more)
  • The Lozen API, a stand-alone, streamlined version of our native interface with a callable library and encapsulated logic that makes mainframe data access as efficient as possible  

Connectors are valuable extensions to Lozen, allowing Lozen customers to have simple and secure access to mainframe data from an increasing number of application environments, with high performance and data integrity.

The Lozen OpenAPI Connector

OpenAPI is an open set of standards published by a consortium focused on the value of standardizing software APIs. OpenAPI makes it easy to weave together services from a diverse range of providers into sophisticated composite applications.

By participating in this community, Lozen’s OpenAPI connector makes it possible to access mainframe data, such as VSAM files, from any OpenAPI application.  Many commercial and open-source applications support the OpenAPI specification. In addition to a wide range of open-source tools, Microsoft, IBM, Oracle, Tibco, Software AG, and many other vendors embrace OpenAPI in their commercial products. This means that applications running within any of these contexts can use Lozen to read and update mainframe files by interacting with simple and familiar OpenAPI objects without special customized coding.

An example might be a customer using Microsoft’s Azure Logic Apps, a solution for creating and running automated workflows that integrate apps and data spanning many sources, including mainframe data accessed via Lozen. Logic Apps workflows can combine data from a variety of sources — SQL and NoSQL databases, Salesforce.com, email systems, cloud applications — and now mainframe data.  From any Azure Logic Apps workflow, Lozen’s OpenAPI implementation lets you embed steps that read or update mainframe datasets in the same manner as Logic Apps accesses any other types of data.

Best of all, the approach requires zero custom coding and is entirely declarative. You just configure an OpenAPI object to connect to the desired Lozen server and embed access to your mainframe data wherever needed. Whether you want to fetch an entire mainframe file or simply look up a single record in a keyed VSAM file, you just select the desired operation and configure Lozen’s OpenAPI connector to perform the task you want.

Although this example focuses on Microsoft Azure Logic Apps, similar capabilities are possible from many applications supporting the OpenAPI specification. If a Tibco or Software AG customer needs to access mainframe data, the Lozen OpenAPI connector supports these products in the same way as Azure Logic Apps is supported, and there are many popular open-source tools embracing OpenAPI too.

Whatever software is being used, Lozen’s OpenAPI feature provides the necessary methods and connections for accessing mainframe data through the Lozen server running on the z/OS platform.

The Lozen API

If you are developing applications outside the context of MuleSoft or other tools supporting OpenAPI (such as Microsoft Azure Logic Apps, IBM Cognos, Talend, Boomi, Amazon Lambda, Software AG webMethods, and TIBCO Cloud Integration), our stand-alone API can be used to simplify accessing mainframe data using Lozen.

Since Lozen is built on industry-standard protocols like NFS, you can use normal operating system functions like “read” and “write” to access Lozen. But if you prefer to have a simplified API that encapsulates the logic for accessing things like keyed VSAM files, now you can use the Lozen API.

The Lozen API is available in two forms:

  • A DLL format that is optimized for use with programming languages like C/C++
  • A Java-friendly version of the API shipped as a simple JAR file 

Whichever approach you use, the API includes functions for opening and closing Lozen files; reading and writing data; and performing control functions like searching for records by key or record number.

Visit our YouTube channel to watch Vince Re, VirtualZ’s CTO, talk about the Lozen API.


If you are an application developer looking for ways to integrate mainframe data into your applications, Lozen offers several new ways to simplify these tasks.

Our OpenAPI Connector lets Lozen work in any system supporting OpenAPI.  For stand-alone use, Lozen’s internal API is available for nearly any application.

Learn More

To learn more about how to unlock the power of real-time, read-write mainframe data access with Lozen:


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