Quite rightly, with NDB Client Library, it would be necessary to have the NDB model in your Service. And I agree with you about the validity of a use case for sharing models among services without having to share the model among all the services that use the model. However, there is presently no other implementation that allows such access to your Model definitions outside of your Application code (apart from using Symlinks locally and uploading to App Engine, that is).
I have created a Feature Request <https://issuetracker.google.com/118167498>with the product engineers and you can add more description to the feature request for better detailing of the request. Be sure to Star the issue tracker link for regular updates on the implementation of the feature, however there is no ETA available for this feature at this time. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/b12b5ca1-0673-4046-bd7e-befced0ff817%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.