If you are using Maven or Gradle, add the following dependency to the _dependencies_ section of your
project descriptor to access the Vert.x Core API and enable the JavaScript support:

* Maven (in your `pom.xml`):

[source,xml,subs="+attributes"]
----
<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-core</artifactId>
  <version>3.5.4</version>
</dependency>
<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-lang-kotlin</artifactId>
  <version>3.5.4</version>
</dependency>
----

* Gradle (in your `build.gradle` file):

[source,groovy,subs="+attributes"]
----
compile "io.vertx:vertx-core:3.5.4"
compile "io.vertx:vertx-lang-kotlin:3.5.4"
----