When prototyping we run the viewer from the command line (rather than deploying to a full webapp, a topic we cover in Chapter 5, Deploying Restful Objects Webapps). We therefore need to add a reference to the viewer in the commandline project's pom.xml:

<dependencies>
  ...
  <dependency>
    <groupId>org.starobjects.restful</groupId>
    <artifactId>viewer</artifactId>
    <version>${restfulobjects.version}</version>
  </dependency>
  ...
</dependencies>