What's new in IBM Developer for z/OS on VS Code

6.6.1 - 2026/07/22

This minor bug-fix release includes security fixes and improvements. Security fixes identified through AI-assisted analysis, in addition to traditional scanning and security reporting tools, address vulnerabilities in third-party dependencies and product code.

• Fixed an issue where Remote Preprocessor failed when local file names contained lowercase characters.
• Fixed an issue where directory reads caused excessive CPU usage.
• Fixed an issue where the zowe rse list jobs command required the -owner option to display the job list from the z/OS® system.

See the full list of changes in the Changelog

6.6.0 - 2026/06/19

IBM® Developer for z/O®S on VS Code 6.6.0 is now part of IBM Bob™ Premium Package for Z

6.5.1 - 2026/05/29

IBM® Developer for z/OS® on VS Code with Z Open Editor 6.5.1 includes various bug fixes and minor improvements based on reported issues and requested enhancements. The release also adds support for the recent Zowe 3.5.0 update.

• Fixed the issue in the z/OS Resource Table where PDS member searches by name pattern only (without content search) displayed 0 match for '' with empty results for RSE type profiles. Member name pattern searches now display properly.
• Fixed the issue where invalid search parameters could not be processed and prevented access to PDS members in the z/OS Resources Table.
• Fixed the issue where the MCP tool zowe-get-all-job-spools-output hung when downloading spool content without specifying an output directory. The tool now resolves to the workspace folder path when no outDir is provided.

See the complete list of fixes and improvements for this release in the Changelog for details.

6.5.0 - 2026/04/10

IBM® Developer for z/OS® on VS Code 6.5.0 expands on advanced capabilities across z/OS development workflows. This release delivers user build improvements for multi-root workspaces, expands MCP server functionality with new tools and parameters, and adds HLASM usability refinements. It also introduces rich EXEC CICS® hover help for COBOL and includes a broad set of fixes and enhancements for IBM® RSE API Profiles and the Plug-in for Zowe™ CLI.

User build improvements driven by customer feedback: Several issues affecting user build in large workspaces with multiple Git repositories are resolved. This release fixes DBB command-line parsing in ZAPP files, improves handling of additionalDependencies entries that use glob patterns, and prevents failures when dependencies are stored in a different Git repository than the program you build. A new setting zopeneditor.userbuild.userSettings.preserveWorkspaceNames, supports multi-root VS Code workspaces by preserving workspace names during dependency uploads.

Major expansion of MCP server capabilities: This release adds new and enhanced Model Context Protocol tools to improve interaction with code, profiles, jobs, data sets, UNIX System Services files, and DBB build results. New capabilities include control flow and data flow tools for COBOL and PL/I, interactive tools to create and update Zowe team configuration and credentials, DBB build-result retrieval tools, password update support for RSE API profiles, member-name search enhancements for zowe-search-dataset, and new optional parameters across JES, UNIX System Services, and data set tools. The release also adds support for selecting an alternative Zowe profile when using MCP tools, which provides flexibility across multiple environments. For a full list of MCP tools, see IBM Developer for z/OS on VS Code MCP Tools.

Better HLASM editing experience: HLASM support continues to improve with enhancements visible immediately while editing. This release improves TextMate and semantic token syntax highlighting, especially for continuation lines, comments, and string literals. Folding range support is added for macro definitions, structured programming constructs, and consecutive comment blocks. These updates make large HLASM source files easier to scan, navigate, and maintain.

New EXEC CICS hover help for COBOL: Hover help for EXEC CICS statements now includes command descriptions, options, response codes, examples, and links to online CICS API documentation. This enhancement enables faster understanding of unfamiliar statements and reduces the need to leave the editor while working with CICS logic.

Many refinements and fixes for RSE API Plugin for Zowe CLI: The RSE API CLI update in 6.5.0 introduces quality and usability improvements. Encoding fallback behavior for UNIX System Services file transfers is refined. The new zowe rse admin download-logs command retrieves server diagnostics (also available in Z Open Editor). Handling of .zosattributes during uploads is improved. Support is added for tilde and relative local paths, and upload and download streaming and concurrency are optimized for better throughput. Several issues are resolved, including data set queries, record format validation, special-character handling in owner and prefix values, numeric-only PDS member uploads, and other edge cases. These updates improve reliability in the editor, in Zowe Explorer, and from the command line.

Additional improvements include expanded EBCDIC code page support through ICU adoption, fixes for COBOL diagnostics and expand source behavior, JCL completion fixes, and updates to support log export from RSE API servers.

5.7.3 - 2026/04/10

(Available at IBM Mainframe Downloads only.)

• Fixed security vulnerabilities in third-party dependencies
• Updated to work with Zowe Explorer 3.4.2
• Shipped with ZAPP schema 1.9.0

6.4.0 - 2026/02/19

IBM® Developer for z/OS® on VS Code, together with Z Open Editor and RSE API CLI 6.4.0, introduces new features and enhancements. Key updates in this release include:

Control and data flow export: You can now export your graph diagrams in six different formats. Some formats include raw data that can be integrated into custom applications or analyzed by AI chat agents.

User Build upload performance improvements: Uploading large numbers of include files or additional dependencies as part of user builds (with full upload) benefits from significant performance improvements. You can configure Z Open Editor to perform up to 50 uploads in parallel. Enhancements also include improved handling of nested directories and faster tag creation with RSE API 1.2.4. The CLI leverages these improvements as well. With RSE API, builds are not limited by the number of available address spaces, unlike z/OSMF. The maximum number of include files that can be downloaded in parallel increased from 10 to 50.

New and improved MCP tools: The changelog documents improvements made to the MCP (Model Context Protocol) tools. Added tools for uploading and downloading to and from data sets as well as UNIX System Services files. In addition, a range of tools was introduced to interact with Wazi Deploy analyzing evidence data files.

30 new ZCodeScan rules: IBM ZCodeScan adds 30 new COBOL rules to improve code quality and security analysis (27 for code review, 3 for security review) and refines the schema for rule customizations. See the documentation and changelog for details on migration steps required for custom rules files.

Additional fixes and minor enhancements include updates to Quick Fix menus introduced in 6.3.0, improved HLASM macro handling, resolution of a COBOL issue with multi-line REPLACING, and improved error handling and data returned by the ZCodeScan MCP tools.

6.3.0 - 2026/01/23

The January release introduces a range of enhancements and fixes. Key highlights include:

Quick Fix

• Language server protocol support for COBOL, PL/I, and JCL now includes Quick Fix code actions.
• Hover over a syntax error in the editor and select Quick Fix to view suggestions for resolving the issue.
• Proposals include corrections for misspelled keywords, variable names, and function names.
• Quick Fix also assists in adding qualifiers to ambiguous variable references and creating new COBOL paragraphs or sections for missing PERFORM statement references.

Semantic Syntax Highlighting Refinements: Feedback indicated that switching from TextMate-based syntax highlighting to semantic highlighting caused distracting color changes during parsing. Color schemes are now aligned to ensure a consistent visual experience without unexpected changes during editing.

For advanced features, several updates are provided:

IBM ZCodeScan Integration with PL/I: ZCodeScan integration now supports PL/I with an initial set of 11 rules. Additional rules are planned for future updates. The updated list and usage examples are available in the samples repository.

Graph Browser Enhancements:

• The layout of graph browsers is optimized to make them more compact for reviewing larger programs.
• Additional event handlers are available, such as mouse clicks on data flow links to navigate to the MOVE statement in the code (for straight lines) or to the exact variable definition (for dotted lines).
• Node selection is improved so that clicking anywhere in a paragraph or section selects the outer paragraph node.
• Files containing multiple programs are now correctly represented in both the control flow graph and Call Hierarchy views.

Additional Updates:

• Shift-In/Shift-Out (SI/SO) and double-byte character support for JCL
• Refinements to preprocessor support for editing
• Greater control over enabling or disabling the advanced Problems view feature for user builds
• EXEC CICS and EXEC SQL support for HLASM
• A new setting for scanning remote HLASM macro files

6.2.0 - 2025/12/05

The final release of the year introduces multiple enhancements designed to improve the development experience.

Centralized ZCodeScan Rules Management: The ZCodeScan integration is revamped to simplify configuration. Previously, each Git repository required its own rules file. Rules can now be centralized for an organization, as follows:

• Store rules in a dedicated repository and load them into a multi-root workspace alongside application repositories.
• Share rules across projects or maintain different rule sets for different application types.

This capability is enabled through a new ZCodeScan profile type in the ZAPP file, which specifies the rules file to use. The release also introduces the first step toward custom rules: declarative rules can be defined using regular expressions in a separate file referenced in the ZAPP file.

Improved Control and Data Flow Browsers: Enhancements to the graph browsers include:

• Compact control flow layout for easier navigation of large programs.
• Search functionality added to the data flow browser, consistent with the control flow experience.
• Context-aware selection: right-click in the code to open the browser and highlight the corresponding paragraph (control flow) or variable (data flow).

Several other refinements and fixes are included, such as:

• The ability to customize the columns of the z/OS® Resources table.
• An MCP tool for changing the default Zowe™ profile to set the correct context for AI Chat interactions.
• Support for HLASM on z/OS 3.2 with pre-scanned SYS1.MACLIB macros for code completion.
• RSE API CLI commands to copy files between UNIX System Services and data sets.
• Localization to Simplified Chinese (zh-cn) and Traditional Chinese (zh-tw).
• Bug fixes and stability improvements.

6.1.1 - 2025/11/13

Hotfix updates are available for IBM Developer for z/OS on VS Code 5.7.1 and 6.1.0. Z Open Editor 6.1.1 and the IBM RSE API Plug-in for Zowe CLI 6.1.1 are published in the VS Code Marketplace. Version 5.7.2 is available only from the Mainframe Download Site. All 6.1.1 release artifacts are also available there.

Fixes included in this release:

• Fixed the issue that prevented using environment variables in Zowe™ team configuration files when using MCP tools.
• Fixed the issue that prevented uploading nested dependency folders in user builds on Windows.
• Fixed the issue with the copy unix-cross-lpar command to show a more consistent progress bar for large file and directory copies, and updated the command to use a temporary download location rather than current workspace.
• Adopted authOrder for RSE profiles when logged in with token authentication to ensure that sessions retrieved from the CLI use the correct authentication method.
• Fixed the issue with the disable-symlink-resolution flag for the zowe rse search uss command by adding a version check and an appropriate error message if the RSE API host component is below v1.2.3.

5.7.2 - 2025/11/13

(Available at IBM Mainframe Downloads only.)

• Fixed the issue that user build menu items were not available for REXX files when zopeneditor.userbuild.alwaysShowCommands was enabled.
• Fixed issues with using local HLASM macros on Windows when specifying an absolute path with a drive letter and a glob pattern. Added the includeFileExtensions user setting to HLASM to enhance the performance of the local macro scanner by preventing scans of non-HLASM files.
• Fixed the issue where local HLASM macros did not work reliably for relative maclib paths in multi-root workspaces.

6.1.0 - 2025/10/24

Version 6.1.0 is now available, introducing new capabilities and a revised licensing model for accessing IBM Developer for z/OS on VS Code's Advanced Features.

Introducing IBM Developer for z/OS Select 1.0.0 which is a new product bundle that offers organizations a choice of editors for application development. It supports team preferences by enabling editing in both Eclipse and VS Code. This edition enables a distinct subset of advanced capabilities in Z Open Editor compared to the Enterprise edition. The redesigned Welcome page provides an overview of available trial features and lists the capabilities included in both the Select and Enterprise editions.

This latest release includes the following enhancements:

• Added "Show Call Hierarchy" and "Peek Call Hierarchy" context menu actions to COBOL language support. Select a paragraph or section and review all associated perform targets or sources.
• Expanded the advanced feature control flow graph browser to support PL/I programs. Enhancements include the ability to select and view subsets of the graph and to search for nodes using regular expressions.
• Added a graph browser feature for COBOL to visualize data flow. Select any variable in the source code and open the Data Flow Browser from the "Show In" context menu to display the data used to populate the variable, as well as where the variable's content flows, such as how it's used downstream.
• Expanded the list of Model Context Protocol tools by adding tools to execute ZCodeScans and User Builds, and to perform source code actions such as formatting multiple files and removing their sequence numbers in batch.

A short demo video is available: Demonstration of MCP Tools in IBM Developer for z/OS on VS Code 6.1.0

The RSE API CLI now includes several new options for working with UNIX archive files.

6.0.0 - 2025/09/19

The latest release introduces AI capabilities through its first set of Model Context Protocol features, which integrate with VS Code's Agent Mode. This enhancement enables AI to access contextual information from Z Open Editor across both the local workspace and the z/OS development environment.

Other major additions in this release include:

• COBOL control flow diagrams: A graphical browser for examining "perform" calls.
• CICS TS 6.3 support: Adds all the new and updated statements to COBOL and PL/I language support.
• "Expand Source Code" for PL/I: Expands PL/I macros in addition to include files.
• HLASM enhancements: Includes new z17 operands in code completion.
• Several fixes and updates for COBOL, JCL and HLASM.

Breaking changes:

• VS Code 1.102.3 or newer required
• Java 21 LTS minimum version required
• New license activation kits required for major version upgrade

5.7.1 - 2025/08/29

A bug fix release addressing several issues:

• Fixed JCL language server errors about missing PROC files
• Fixed language detection issues with RSE API profiles
• Fixed CLI command errors when creating members
• Fixed Submit Job confirmation dialog hyperlink errors

5.7.0 - 2025/08/22

The August release includes several enhancements and fixes.

Added Language Detection for z/OS data set members using the RSE API's scan feature to automatically determine the programming language and set it in VS Code.

The Editor now integrates with IBM CICS® for Zowe Explorer, introducing the CICS Resource Inspector view accessible directly from COBOL source code through a codelens.

Enhancements to ZAPP file editing include support for additional variable types and preview hovers showing built-in variables such as ${javaHome} and ${workspace}.

5.6.0 - 2025/07/25

The July release addresses technical debt and introduces key improvements.

Added support for mounted drive letters and UNC path names for Windows users. You can now share copybooks and include files on a network drive.

Productivity enhancements for ZAPP file creation include error messages in the Problems view for undefined custom variables or misspelled built-in variables.

The data elements table is enhanced with advanced filter options using regular expressions and support for exporting data as CSV files.

Zowe Explorer paging for data sets and members now works with RSE API profiles.

5.5.0 - 2025/06/24

IBM® Developer for z/OS® on VS Code v5.5.0 introduces new capabilities and enhancements including:

• Language support for COBOL V6.5 and PL/I 6.2
• Semantic syntax highlighting for COBOL and HLASM based on parsing results
• Improved resolution of JCL PROCs and HLASM macros from z/OS
• New RSE API CLI terminal commands for editing and comparing files

Two major new Advanced Features:

• IBM ZCodeScan: A linter-like experience for COBOL that scans for best practice violations and security vulnerabilities
• Data Elements View: Displays data elements within COBOL or PL/I programs with browsing, searching, sorting, and filtering capabilities

The 3270 emulator now opens directly inside VS Code in a dedicated webview and supports the latest Zowe authentication methods.

5.4.1 - 2025/05/14

• Added ability to execute preprocessor with custom file extensions
• Preprocessor on z/OS® for local files now uses zopeneditor.autoPreprocessor setting
• Added new setting zopeneditor.jcl.enableResolvingProcs to toggle PROC retrieval
• Fixed user build issues with z/OSMF and SSH profiles
• Fixed file corruption issues with Shift-In/Shift-Out characters on Windows
• Improved credentials management with Zowe Explorer 3.2.0

5.4.0 - 2025/04/25

This release focuses on enhancements and bug fixes:

• Added ability to run preprocessor for COBOL or PL/I for local files on z/OS®
• Regular expression support for searching file names and content in z/OS Resources table
• Reimplemented parsing for double-byte characters with byte counter in status bar
• Added Expand Source Code operation to JCL files
• Improved credentials caching to reduce login prompts

New installations now include a 90-day trial for Advanced Features.

Extension packs now include IBM CICS® for Zowe Explorer and IBM CICS Plug-in for Zowe CLI.

5.3.0 - 2025/03/21

Released Z Open Editor and RSE API Plugin 5.3.0 with JCL editor PROCs support and new RSE API CLI commands.

Added advanced 3270 emulator support (RCE - Remote Connection Emulator) with features including:

• Fully customizable user experience
• Advanced text selection for cut/copy/paste
• Customizable screen keyboard
• Bidirectional editing

Added paging features to the z/OS Resources table for improved performance with large data sets.

5.2.0 - 2025/02/07

The first release of 2025 focuses on quality improvements and bug fixes:

• Added support for custom HLASM macros stored in z/OS data sets
• Optimized Zowe Explorer virtual file system utilization with progress bar
• Added user setting to start user build on arbitrary files
• New warning dialog for password expiration with RSE API
• New RSE API CLI commands for cross-LPAR operations

Documentation revised for Red Hat® OpenShift Dev Spaces and GitHub Codespaces with Dev Containers.

5.1.0 - 2024/12/11

Version 5.1.0 completes the transition to Zowe™ v3 by fully adopting the virtual file system introduced with Zowe Explorer v3.

Key features:

• Unified file resources across Zowe Explorer and Z Open Editor
• New setting zopeneditor.zowe.readonlyRemoteIncludeFiles to enable editing remote files
• PL/I preprocessor support for expanding macros using PL/I compiler on z/OS®
• New RSE API CLI cross-LPAR commands and paging parameters

Support for Red Hat's OpenShift Dev Spaces directly, retiring Wazi for Dev Spaces.

5.0.0 - 2024/10/18

Version 5 introduces breaking changes and major updates:

Breaking changes:

• Zowe v3 required (Zowe Explorer 3.0.2+ and Zowe CLI 8.x+)
• VS Code 1.91 or newer required
• Java 17™ or newer required

New features:

• Localization to French, German, Japanese, Portuguese, and Spanish
• Improved double-byte character support
• User builds with IBM DBB 3.0.0 zBuilder
• JCL include file support
• New RSE API CLI commands

Coordinated with IBM Application Delivery Foundation for z/OS 5.0.0 and IBM Developer for z/OS Enterprise Edition 17.0.0.

4.5.0 - 2024/09/19

September 2024 release completes the z/OS® Resource Table with content search for PDS members and UNIX System Services files.

Preprocessor support extended to PL/I programs with examples in Java™ and REXX.

New experimental content menu action to expand COBOL programs embedding nested copybooks and substituting REPLACING values.

New RSE API CLI commands for copying content between LPARs and encoding conversion options.

4.4.0 - 2024/08/12

August 2024 release focuses on incremental refinements:

• z/OS® Resources Tables with content search and new filter options
• Preprocessor support with z/OSMF and Cancel button
• HLASM code completion for local macros with parameter navigation
• Code folding implementation for COBOL
• New UNIX System Services command for RSE API CLI
• Air gap installation option for the plugin

4.3.0 - 2024/06/18

IBM Z® Open Editor 4.3.0 adds support for Job Control Language (JCL) with:

• Outline view
• Real-time syntax checking
• Code completion

Advanced capabilities enhanced with remote preprocessor execution on z/OS® using TSO commands.

Language support improvements for PL/I v6.1 and enhanced double-byte character string editing.

4.2.0 - 2024/05/16

Released Z Open Editor 4.2.0 with two Advanced Features additions:

1. HLASM macro file support with hovers, document links, go to definition, and code completion
2. z/OS® Resource table with UNIX System Services support for browsing, filtering, sorting, and file operations

Added COBOL User Defined Functions support and enhancements for watsonx® Code Assistant for Z integration.

4.1.0 - 2024/03/28

Key updates for watsonx® Code Assistant for Z integration:

• Graphical end-to-end walkthrough for setup
• New navigation from generated Java™ code back to COBOL sources using CodeLens
• Various bug fixes

RSE API CLI additions:

• Content search commands for UNIX System Services files
• Key-value pair storage commands using RSE API mini database

4.0.0 - 2024/03/15

Major update introducing enterprise-level advanced capabilities requiring licensing:

1. Local preprocessor support for COBOL: Run preprocessor on local workstation with automatic rerun on save
2. z/OS Resources table: Feature-rich sortable table view extending Zowe Explorer
3. Advanced Dependency Based user build error reporting: Automatic log download and parsing in Problems view

Core Z Open Editor features remain free with full language support for COBOL, PL/I, REXX, and HLASM.

Upgraded dependencies require VS Code 1.81.0+, Zowe CLI 7.21.3+, and Zowe Explorer 2.14.1+.

IBM Z® Open Debug v4.0.0 redesigned with Zowe CLI profiles and new Debugger Profile view.