MDRest4i - REST APIs Integration for IBM i

Quick, Easy, and Secure IBM i Integration - Create REST APIs & Consumers Using RPG Skills

Fast, Simple, Scalable…

Programmers with RPG and SQL skills, use MDRest4i to quickly and easily build REST APIs and REST Clients, rapidly  integrating their IBM i applications with anything REST.

IBM i application experts can enforce their business rules without having to rely on middleware, code abstractions, or connectivity drivers.

Employing an RPG ILE framework for IBM i environments, MDRest4i hides code complexities while standardizing flow where possible. MDRest4i’s performance-optimized code structure for parsing and translations means lightning quick response times.

MDRest4i SDK

Automate generation of boilerplate API and Consumer RPGLE and SQL code from any integration requirement.


MDRest4i iCore

Add RPGLE business logic to layered architecture for low code maintenance without limiting flexibility.


MDRest4i Documenter

Use Wizards to build and edit API specs and export to API Developer Portal and Atlassian Confluence documentation.


What are people saying about MDRest4i?

Rest4i is one of the slickest tools I have seen on the IBM i in many years.

I've been an RPG programmer for a long time, and it taps into the power of the IBM i like no other tool I've seen.

 Rest4i has worked even better than we could have hoped for. Our API strategy has leaped years ahead.

We had our first REST service running on our IBM i within an hour of downloading Rest4i.

Generate REST APIs and Consumers From Anything

MDRest4i SDK Web Console

  • Generate REST API and Consumer programs from all commonly used requirement definitions.
  • Generated RPGLE logic includes data structures/definitions, parsers, JSON/XML writing, assignments, SQL/IO, error-handling, logging, analytics, SSL/TLS, OAuth/JWT, mapped to API input and output payloads, and parameters.
  • Separate logic handling for each HTTP method and component.
  • Generators are exposed as IBM i commands and REST APIs, with customizable templates and examples for each typical use case.
  • Web-based UI supports editing, collaboration, and documentation, with exit points for integration with mainstream workflow, DevOps, and API management systems, including Jira, GitHub, MuleSoft, API Connect, SCM, and more.
  • Form-based SWAGGER/OAPi editing. Import existing SWAGGER specs, POSTMAN requests, or rapidly build API’s and Consumer specifications without SWAGGER skills

Develop Sophisticated APIs and Consumers Using Minimal RPG and SQL

  • MDRest4i layered RPGLE architecture stores reusable complex logic in copybooks and modules.
  • Developers need only use RPG and SQL for business logic and input/ output of mission critical data.
  • Integrate existing programs, procedures, stored procedures, or service programs using standard RPG.

Document APIs and Build Developer Portals

  • Generate interactive documentation of API and consumer specifications, with built-in testing capabilities.
  • Provide one web UI for internal developer collaboration and one for self-service API developer and consumer documentation.
  • From your Open API specs, MDRest4i generates beautiful, interactive documentation in your Atlassian Confluence pages.

MDRest4i Accelerator

  • Presents interactive documentation of API and consumer specifications, with built-in testing capabilities.
  • Automatically generated from your OpenAPI (formerly known as Swagger) Specification, with visual documentation used for back-end generation and client side consumption.
Download a PDF

MDRest4i Developer Portals

  • Generate editable developer and user documentation into standard user templates. Separate into environments for multiple user groups.
  • One web UI for internal developer collaboration and one for self-service API developer and consumer documentation.

Export to Atlassian Confluence

  • From your Open API specs, generate beautiful, interactive documentation in your Confluence pages.
  • Integrate API, application, and business documentation into a single portal for partner, internal developer, or external consumption of your APIs.

Integrated API Development with Modern IDE and SCM Options

Accelerator and iCore

  • A rich web UI to manage, edit, and generate RPGLE code from Open-API (Swagger) specifications and definitions.
  • REST API (developed on IBM i using iCore) that uses OAS3 (SWAGGER), definitions to generate RPGLE APIs and Consumers
  • IBM i commands, examples, and templates in RPGLE for each typical use case for manually building APIs and Consumers.
Functional Breakdown


  • Integrated with MDCMS Object Request user actions in MDOpen RDi plug-in, iCore’s IBM i commands are exposed in a rich, Eclipse-UI environment
  • A set of RPGLE REST APis integrated with MDRest4i Accelerator, over MDCMS (built using iCore) expose key integration points in the MDCMS flow and change management data and processes

Key Benefits of MDRest4i


No middleware, code abstractions, or connectivity drivers. Lean, performance optimized code structure for parsing and translations = lightning quick response times.


Layered code architecture using typical RPGLE constructs and concepts. Hides complex code while standardizing flow where possible. Low code maintenance without limiting flexibility.


Structured code makes development and maintenance of code consistent, and easier to learn and debug. Changes are quicker to design, code, and test. Also allows automated-unit testing.


Structured code architecture makes code generation possible. Accelerate development effort rather than replacing it. Templates allow scalable flexibility without limitations.


Structured code architecture makes code documentation easier and facilitates auto documentation. API docs are critical for benefits associated with self-service economies.


MDRest4i follows industry standards by default. This lowers risk during code transformation and improves re-usability. It also makes training of new staff more cost-effective and efficient.

API Quick Start

Learn how to build, secure and deploy REST APIs integration in any IBM i environment

End-to-End API Pilot with Quick Start

Digital integration potentially spans many architectures, tools, methodologies, and standards. Many of these are new and constantly evolving.

Making the right decisions and selections in managing, developing, and deploying APIs is critical for security, flexibility, and competitiveness. An API project typically involves business stakeholders, infrastructure, and development teams.

Our experienced consultants can bring these technologies and teams together in a two-week Agile sprint, using a focused business deliverable to build a functional REST API Pilot.

Contact us to chat about API Quick Start

See MDRest4i in Action - Build REST APIs Integration on IBM i

Accelerator Demo

Generate REST API documentation RPG REST APIs automatically, while mapping API fields to the DB2 database fields using MDRest4i Accelerator Cloud.

iCore Demo

Watch how MDRest4i simplifies building REST APIs with complex and structured JSON using existing RPG skills.