Since its introduction more than 2 years ago, Google Drive Realtime API has played a key part in helping developers integrate collaborative features for their files in Google Drive. Features have been added at a steady pace and have included undo/redo, import/export functionality, moving items between lists, and more. However, as a developer, it was cumbersome to develop applications using the Realtime API since it required that you were connected to the servers, authentication/authorization was performed, and so on. As a result, the Google Drive Team has introduced key enhancements to the API that make it much easier to work with the API.
The first feature is called In-Memory Mode, which allows you to work with a Realtime Document without being connected to the servers. No user login or authentication is needed and the standard API is available to you to work in this mode. Use cases where this could be useful is building out applications that do not require login, testing your application, or just building out a proof of concept. While working in this mode, you will not receive any changes from collaborators and methods that involve collaboration will return dummy data.
The Realtime API documentation has gone through a major facelift with a dedicated home page and detailed guides on new features, best practices, and more. Check out the release notes for more details.