Micronaut Application Framework micronaut-core

Apache-2.0 License


Build Status

Micronaut is a modern, JVM-based, full stack Java framework designed for building modular, easily testable JVM applications with support for Java, Kotlin and the Groovy language.

Micronaut is developed by the creators of the Grails framework and takes inspiration from lessons learnt over the years building real-world applications from monoliths to microservices using Spring, Spring Boot and Grails.

Micronaut aims to provide all the tools necessary to build JVM applications including:

  • Dependency Injection and Inversion of Control (IoC)
  • Aspect Oriented Programming (AOP)
  • Sensible Defaults and Auto-Configuration

With Micronaut you can build Message-Driven Applications, Command Line Applications, HTTP Servers and more whilst for Microservices in particular Micronaut also provides:

  • Distributed Configuration
  • Service Discovery
  • HTTP Routing
  • Client-Side Load Balancing

At the same time Micronaut aims to avoid the downsides of frameworks like Spring, Spring Boot and Grails by providing:

  • Fast startup time
  • Reduced memory footprint
  • Minimal use of reflection
  • Minimal use of proxies
  • No runtime bytecode generation
  • Easy Unit Testing

This is achieved by pre-computing the framework infrastructure at compilation time which reduces the logic required at runtime for the application to work.

For more information on using Micronaut see the documentation at micronaut.io

Example Applications

Example Micronaut applications can be found in the Examples repository

Building From Source

To build from source checkout the code and run:

./gradlew publishToMavenLocal

This will publish the current version to your local Maven cache. To get the CLI operational you can do:

export MICRONAUT_HOME=/path/to/checkout
export PATH="$PATH:$MICRONAUT_HOME/cli/build/bin"

You will also need to checkout the Micronaut Profiles and run ./gradlew publishToMavenLocal there too.

You should then be able to mn create-app hello-world.

To build the documentation run ./gradlew docs. The documentation is built to build/docs/index.html.

Contributing Code

If you wish to contribute to the development of Micronaut please read the CONTRIBUTING.md


Micronaut is using Semantic Versioning 2.0.0. To understand what that means, please see the specification documentation. Exclusions to Micronaut's public API include any classes annotated with @Experimental or @Internal, which reside in the io.micronaut.core.annotation package.


Github Actions are used to build Micronaut. If a build fails in master, check the test reports.