The supported mechanism for embedding Gradle is the Tooling API, which is briefly described in the User Guide. The Tooling API is quite sophisticated in that it is both forward and backward compatible with different Gradle versions: so you can embed the Tooling API v1.4, and you’ll still be able to access information about a build that uses features introduced in Gradle v1.6.
Because of this, the model presented by the Tooling API is an abstraction over the core Gradle Project model. So far, this abstraction has been targeted as IDE integrators, but it should also be useful for other embedding use cases.
So the answer to “how can I get a Project interface instance” using the Tooling API is that you can’t. But getting information about the project dependencies is possible using either the IDEA or Eclipse project model. In the future we’d like to add this capability to the generic “GradleModel”, but that hasn’t happened yet. Check out the Tooling API samples for how this can be done.
I don’t really understand what you’re trying to achieve, so I’m not sure that the Tooling API will have the capabilities you’re looking for. But take a look and let us know if there’s something missing.