Accept an array of new objects in response from server

I'm currently running into an issue where I want to build an array of new objects from my Rails server, and provide it to the user to confirm/edit before saving.

However Ember Data requires an ID in the object in order to use it.

Is there something that I can do in the serializer to tell ember that these are new objects and that they won't have an id? Should I be going about this a different way?

The main reason that I'm using the server for this is because there's a library that does exactly what I need, saving me loads of time instead of doing it manually on the client.