I just talked about this with Christian, and I think that it is better suited inside the Deploy phase (rather than the Validate, Verify or Install phases). What the Unpack goal does is that it simply downloads the GAE SDK, in order for the maven-gae-plugin to call the scripts that will start the upload to GAE. Therefore, the SDK is only needed for deployment purposes. So, the SDK is **not** a dependency of the application, but a dependency of the maven-gae-plugin. The Unpack goal should only be executed when we're about to upload the application, that's why I believe it better fits in the Deploy phase. That way, it'll be executed the least times possible :)