Last August, this API went "invitation only", and since shortly thereafter it's been closed to new developers: https://developer.amazon.com/amazon-drive
"The Amazon Drive API and SDKs are currently closed to new developers.
Thank you for your interest. We received an overwhelming number of API invitation requests with many innovative integration scenarios. We have ended the invitation period to focus on enabling new customer experiences with current developers."
Does Amazon have any plans to reopen this API?