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KaiZen OpenAPI Editor Logo

KaiZen OpenAPI Editor for Eclipse

KaiZen OpenAPI Editor is an Eclipse editor for the industry standard API description language, formerly known as Swagger. It now supports both Swagger-OpenAPI version 2.0 and OpenAPI version 3.0.

KaiZen Editor is a core component of RepreZen API Studio, a comprehensive solution for API modeling, documentation, visualization, testing and code generation, built on Eclipse.

We welcome your suggestions and contributions!

Eclipse Installer

KaiZen OpenAPI Editor is available on Eclipse Marketplace. Drag-and-drop this button into Eclipse Oxygen or later to install, or see below for other options:

Drag to your running Eclipse workspace.

NEW! OpenAPI 3.0 Editing

KaiZen OpenAPI Editor now features full support for the OpenAPI version 3.0 specification. See here for further details.

Feature Highlights




Code Assist

Code templates:

Keywords and values:

Code Assist for References

Code assist for references has several scopes which can be viewed in sequence by pressing Ctrl+Space repeatedly:

  • The first scope shows only elements from the current document.
  • The second expands it to elements from the containing project.
  • The third shows elements from the entire workspace.


Pressing the hotkey a fourth time starts the cycle over again, with document scope.

Navigation to a Reference

You can navigate to a reference using Ctrl+Click:

Quick Outline

Quick Outline can be invoked with Ctrl+o. Similar to code assist for references, it has three scopes: model, project, and workspace. It also allows filtering:


Outline View shows the contents of the active OpenAPI spec:

Installing KaiZen OpenAPI Editor

KaiZen OpenAPI Editor requires Java 8 (64-bit) and Eclipse Oxygen or later.

Installing from Eclipse Marketplace

The Eclipse Marketplace solution is the easiest way to install KaiZen Editor into an Eclipse IDE. You can drag-and-drop the Install button from the browser into your Eclipse IDE, or use the built-in Eclipse Marketplace Client.

Drag to your running Eclipse workspace.

Installing from the Update Site

You can install KaiZen OpenAPI Editor into your Eclipse IDE by clicking Help > Install New Software... > Add... This will show a dialog box where you can select the location of the update site. Use the update site as the URL.

Installing RepreZen API Studio

KaiZen Editor is included as a core component of RepreZen API Studio, which adds live documentation and diagram views, sandbox testing with the built-in mock service and Swagger-UI, powerful code generation, and other features.

RepreZen API Studio is available through two different installation options:

  • API Studio Desktop installs as a standalone desktop application on Windows, MacOS or Linux.
  • API Studio for Eclipse installs into an Eclipse IDE distribution, allowing you to use RepreZen's API design, documentation and development features in your primary Eclipse development environment.
    Drag to your running Eclipse workspace.


See the Troubleshooting Guide for solutions to common problems.

Contributing to KaiZen OpenAPI Editor

We welcome contributions - documentation, bug reports or bug fixes. If you are interested in contributing to KaiZen Editor, please see the Developer's Guide.

We also created a list of good first bugs that are relatively easy to fix.


KaiZen OpenAPI Editor is provided under the Eclipse Public License v1.0

Video: KaiZen Editor in RepreZen API Studio

Editing Swagger-OpenAPI in RepreZen API Studio

Note: KaiZen Editor includes code assist, real-time validation, syntax highlighting, and outline view.
Eclipse Color Theme and EditBox are available as separate plugins.
RepreZen API Studio includes the mock service, live Swagger-UI, advanced code generation, and other features that are not part of KaiZen Editor. See the feature comparison here.