The plugin defines two custom Gradle configurations:
As "gwt-servlet" is used on the server-side, you typically add it to Gradles's "runtime" configuration.
The plugin can automatically add the needed GWT dependencies (gwt-dev, gwt-servlet, ...) for you. Everything you have to do is:
repositories { mavenCentral() }
gwt { gwtVersion='2.9.0' }
If you do not specify the "gwtVersion" property, it is assumed that you are adding the dependencies to the correct configurations by yourselves.
As mentioned before, additional GWT client specific libraries have to be added to the "gwt" configuration. If the binary jar does not contain the source code of the library, you also have to declare the source as dependency.
dependencies {
gwt 'foo:bar:1.2.3'
gwt group: 'foo', name: 'bar', version: '1.2.3', classifier: 'sources'
}