KaiZen OpenAPI Editor is RepreZen's free, open-source OpenAPI editor for Eclipse. KaiZen Editor supports the current OpenAPI 3.0 description language and the older OpenAPI 2.0 (f.k.a. the Swagger specification). It includes essential editing features including syntax highlighting, real-time validation, code assist, quick outline and hyperlink navigation. 

RepreZen API Studio is a complete Eclipse-based OpenAPI modeling environment with powerful features to enable full-lifecycle REST API design, documentation, and development. API Studio uses KaiZen Editor as a core component, and adds live views, mocking, code generation, and more. API Studio is available with flexible subscription plans for individuals and teams.

Here's a feature comparison: 

Installation Options

Install from Eclipse Marketplace into Eclipse IDE (Oxygen or later)

Install as a self-contained desktop application

API Modeling Languages

OpenAPI 2.0
(f.k.a. Swagger specification)
OpenAPI 3.0

API Specification Editing

Code assist for keywords and enum values
Code assist with customizable, context-sensitive code templates
Code assist for reference properties
Code Folding
Outline View and Quick Outline navigation
Hyperlink "go to definition" navigation
Toggle word wrap, line numbers, non-printing characters
Find and replace with regular expression support
Syntax Highlighting
Built-in, customizable light and dark color themes

Built-in scope highlighting with light and dark themes

API Validation and Testing

Real-time validation with error and warning markers, quick fixes, configurable Problems view
Keyword and value validation
Reference property validation
Embedded example validation against specified schema

Integrated API Mock Service

Multi-File Support

Reference property code assist with scope cycling
Quick outline view with scope cycling
Documentation view auto-adapts to component files

Generate a single OpenAPI file from a multi-file project

API Documentation and Publishing

Documentation live view with scroll sync and embedded navigation controls

Diagram live view

Swagger UI live view

API Docs for Confluence  BETA 

Code Generation

Swagger Codegen

OpenAPI Generator

Documentation, Diagram and Swagger UI GenTemplates

Custom code generation

Maven & Gradle Integration

Execute codegen from IDE, command line, or CI/CD

Convenient YAML-based configuration

Licensing & Support

Licensing model
Free, Open SourceSubscription, Open Core
Eclipse Public License 1.0RepreZen License Agreement
Free community support on GitHub
Priority technical support from RepreZen

Available enterprise support plans

Powerful IDE for API-first design,
documentation and development.

Ready to Get Started?

If you like KaiZen OpenAPI Editor, you'll be amazed at what you can do with RepreZen API Studio.

Check out our individual plans and pricing, upgrade to API Studio, and start building world-class APIs today!