How to access PlayRunHooks trait and PlayKeys from inside a sbt plugin

I want to include the workflow of ember cli into a play application. So, I thought of writing a sbt-plugin which when enabled in the play applications build will do few things in the first version:

1. Add a task to run "ember new" to create the UI project in a sub directory
2. Add a PlayRunHook so that when run is executed from the activator shell, it also starts the node server serving the ember js application by setting proper proxy so that the api calls are proxied to the Play application
3. When package is called, it also packages the ember application.
4. Properly sets up the UI Assets to include the ember application.

The problem is I am not able to find out how to add dependency so that I could use PlayRunHook trait and PlayKeys in my sbt plugin.

I want to go by the plugin route because in future I may have more services which will have same kind of workflow.

Please help.