Although some APIs provided ways to integrate with Gmail, none were specifically designed to access all the Gmail features. The beta version of the Gmail API gives users RESTful access to mailboxes under OAuth 2.0. In addition, it supports data types such as messaging, drafts, threads and labels. Like all standard Google APIs, calls are made in HTTPS while responses are received in JSON and XML. Calls can be made from standard web languages using a TCP socket.
The beta is much different than the previous IMAP method of interacting with a mailbox. Instead of requiring access to all of a user’s mailbox, the beta allows pin-point control to the desired area within the mailbox. Lastly, one of the main benefits is speed. For example, user’s used to query everything to figure out what changed. Now, using the beta, they can search the change in the inbox history. This alludes to the pin-point control that is one of the largest differences between IMAP and the beta Gmail API.