WSO2 Micro Integrator 4.4 – New Features, Fixes, and Technical Enhancements

WSO2

June 6, 2025

WSO2 Micro Integrator 4.4 – New Features, Fixes, and Technical Enhancements

WSO2 Micro Integrator (MI) has long been a cornerstone for lightweight, robust enterprise integration. Built on the proven WSO2 Enterprise Integrator framework, MI empowers organizations to connect disparate systems, expose APIs, orchestrate workflows, and manage integration logic at scale.

With the release of WSO2 Micro Integrator 4.4, the platform makes a significant leap—not just in features, but in developer productivity, AI-driven extensibility, and future-proof runtime support. Whether you’re building new integration flows or managing complex API ecosystems, this release delivers enhancements designed to minimize friction, accelerate development, and boost reliability.

What’s New in WSO2 Micro Integrator 4.4

Revamped Developer Experience in VS Code

One of the standout improvements is the redesigned Visual Studio Code (VS Code) plugin. Developers now benefit from:

  • An intuitive project overview panel for seamless navigation.
  • Guided onboarding that automatically configures Java, Maven, and the MI runtime.
  • Out-of-the-box project scaffolding for rapid, consistent team setups.

This update removes setup headaches and helps new users ramp up quickly, reducing time-to-value for integration teams.

One-Click Setup: Zero Manual Configuration

Tedious environment setup is now a thing of the past. With version 4.4, WSO2 MI introduces one-click installation via the VS Code plugin, which:

  • Installs and configures Java and Maven.
  • Sets up the Micro Integrator runtime.
  • Generates a ready-to-use development workspace.

This frictionless onboarding is ideal for both new developers and experienced teams frequently spinning up new environments.

AI-Native Integration with the New AI Agent Module

A transformative addition in this release is the AI Agent Module, enabling intelligent behaviors within your integration workflows. Leveraging retrieval-augmented generation (RAG), developers can now embed AI-powered flows without leaving their familiar tools.

This bridges traditional integration with modern AI capabilities, enabling smarter data handling, dynamic decision-making, and contextual responses based on real-time data.

Low-Code, High-Impact Integration Features

WSO2 MI 4.4 further accelerates development with enhanced low-code tooling:

  • Auto-Generated Connectors: Instantly generate connectors from OpenAPI specs within VS Code, drastically reducing the time required for external API integrations.
  • New Mediators:
    • Scatter-Gather: For parallel processing and aggregating results across endpoints.
    • ForEach: Facilitates batch operations over datasets.
    • Variable Mediator: Simplifies variable manipulation and script reusability within flows.

These features let developers focus on business logic, not boilerplate code.

Simplified Expression Syntax and Editor

Expressions are core to integration logic. Version 4.4 introduces a brand-new expression editor that’s both simpler and more robust:

  • Intuitive expression definitions.
  • Real-time error highlighting and in-line suggestions.
  • Broader function support and improved readability.

This reduces bugs and accelerates development cycles by making expressions easier to write, debug, and maintain.

Real-Time Mediator Testing

Previously, mediator testing required deployment and runtime execution. Now, with the new “Try Mediator” feature, developers can:

  • Simulate payloads directly within VS Code.
  • Instantly observe mediator transformations and routing.
  • Debug flows on-the-fly, dramatically reducing iteration cycles.

This interactive testing is especially valuable for complex transformations and orchestrations, where rapid feedback is critical.

Expanded Connector and Protocol Support

WSO2 MI 4.4 enhances out-of-the-box connectivity with:

  • A new HTTP Connector for easier, more secure HTTP/S interactions.
  • Updated connectors for improved performance and compatibility with modern APIs.

Whether integrating RESTful services, legacy endpoints, or microservices, these updates make integration smoother and more scalable.

Support for JDK 21: Future-Ready Runtime

Enterprises benefit from the latest Java features for performance, security, and language enhancements. With full JDK 21 support, MI 4.4 ensures:

  • Compatibility with current and future Java infrastructure.
  • Smooth migration from earlier JDKs.
  • Access to new features like virtual threads, improved memory management, and advanced diagnostics.

Extensive testing guarantees runtime stability, making this a safe and strategic upgrade for mission-critical deployments.

Additional Enhancements and Bug Fixes

Beyond headline features, WSO2 MI 4.4 includes a range of refinements:

  • Inline Expression Support for mediators like PayloadFactory and Log, enabling more concise flows.
  • Enhanced Environment Variable Injection across all environment-specific configurations.
  • UI Improvements for better usability of mediators and debugging tools.
  • Transparent Release Notes - a comprehensive changelog is available on the official GitHub release page for those seeking detailed insights.

Why This Update Matters

This release is about more than just features - it’s about empowering integration teams to be more productive and agile. WSO2 MI 4.4 aligns with modern development trends by:

  • Reducing setup time and infrastructure friction.
  • Enabling low-code and AI-native development.
  • Supporting continuous feedback through real-time testing.
  • Future-proofing Java-based integration with JDK 21 support.

Together, these improvements make WSO2 Micro Integrator more powerful, accessible, and scalable for enterprise integration.

Final Thoughts

WSO2 Micro Integrator 4.4 is a major step forward in enterprise integration - faster, smarter, and future-ready. From AI agent modules to real-time testing, streamlined expressions, and a refreshed VS Code developer experience, this release underscores WSO2’s commitment to innovation and developer empowerment.

For existing WSO2 users, upgrading to 4.4 is a strategic investment in agility and long-term sustainability. For those evaluating new integration platforms, WSO2 MI 4.4 stands out as a compelling, modern choice for building connected, intelligent digital ecosystems.