# Install

Assuming you’ve already installed Node.js (opens new window), you will need a working JVM. The requirements are either (Java (opens new window) or GraalVM (opens new window)).

$ java -version
openjdk version "1.8.0_265"
OpenJDK Runtime Environment (build 1.8.0_265-8u265-b01-0ubuntu2~20.04-b01)
OpenJDK 64-Bit Server VM (build 25.265-b01, mixed mode)

If you see a similar output, this means your system currently has java 8, which is not the best option as it will not benefit from the high performance engine es4x uses.

# GraalVM/OpenJDK

In order to have a compatible runtime it is recommended to install a higher runtime (for example using jabba (opens new window)). For instructions on installing jabba, please refer to the official manual (opens new window).


Using jabba you can install openjdk 11 and/or graalvm (once) as:

jabba install [email protected]
jabba install [email protected]

And later switch to the desired runtime by executing:

jabba use [email protected] # OR jabba use [email protected]

Once a valid JVM is installed you can optionally install the project management utilities development tool.

# Project Tools

npm install -g @es4x/create # OR yarn global add @es4x/create

The package will install a es4x command globally that can be used to create projects and perform other tasks. To know more about the tool:

es4x --help

# Using NPX

The same package can be used as a one-shot operation with npx. In this case refer to it as:

npx @es4x/create --help

# OS package

When working on CI environments where the amount of packages is limited, the package manager can be installed by unzipping the prepackaged tar/zip file.

ES4X='0.9.0' \
  curl -sL \
  https://github.com/reactiverse/es4x/releases/download/$ES4X/es4x-pm-$ES4X-bin.tar.gz \
  | tar zx --strip-components=1 -C /usr/local

For Windows Operating Systems the same can be done using a zip file instead.


Using npm should be the preferred way to install as it allows easy upgrades and should be portable across different Operating Systems.

# Verify

You should now have a es4x command available in your path, you can test it by running:

$ es4x --help

Usage: java -jar /usr/local/bin/es4x-bin.jar [COMMAND] [OPTIONS]

    bare         Creates a bare instance of vert.x.
    dockerfile   Creates a generic Dockerfile for building and deploying the
                 current project.
    project      Initializes the 'package.json' to work with ES4X.
    install      Installs required jars from maven to 'node_modules'.
    list         List vert.x applications
    run          Runs a JS script called <main-verticle> in its own instance of
    start        Start a vert.x application in background
    stop         Stop a vert.x application
    version      Displays the version.

Run 'java -jar /usr/local/bin/es4x-bin.jar COMMAND --help' for
more information on a command.


For best experience and performance please install GraalVM (opens new window). When working on standard JDK, using Java < 11 will run on Interpreted mode which is not performance or recommended for production.