What is the Gradle artifact dependency graph command?

The command is gradle dependencies, and its output is much improved in Gradle 1.2. (You can already try 1.2-rc-1 today.)

If you want to see dependencies on project and all subprojects use in your top-level build.gradle:

subprojects {
    task listAllDependencies(type: DependencyReportTask) {}
}

Then call gradle:

gradle listAllDependencies

Ah, since I had no dependencies in my master project, "gradle dependencies" only lists those and not subproject dependencies so the correct command ended up being

 gradle :<subproject>:dependencies

so for me this was

 gradle :master:dependencies