Earlier this month, we announced that storage quota is now shared between Google Drive, GMail, and Google+ photos. As part of this change, the Google Drive API and the Google Documents List API will be updated over the next few weeks to start returning the updated storage quota information.

In the Google Drive API, this appears in the about collection.

GET https://www.googleapis.com/drive/v2/about
{
 "kind": "drive#about",
 "quotaBytesTotal": 16106127360,
 "quotaBytesUsed": 17936436,
 …
}


In the Documents List API, this appears in the metadata feed.

GET https://docs.google.com/feeds/metadata/default
<entry>
 <gd:quotaBytesTotal>16106127360</gd:quotaBytesTotal>
 <gd:quotaBytesUsed>17936436</gd:quotaBytesUsed>
 …
</entry>

The new values in the quotaBytesTotal field reflect total storage quota across all the unified products. If you rely on this value, you may notice a change in your apps, but we expect it to behave as if a user has just purchased more storage.

The new values for quotaBytesUsed field will reflect the total amount of storage used across the unified products.  (This field used to reflect the total amount of storage used by Google Drive.)

Ali Afshar profile | twitter

Tech Lead, Google Drive Developer Relations. As an eternal open source advocate, he contributes to a number of open source applications, and is the author of the PIDA Python IDE. Once an intensive care physician, he has a special interest in all aspects of technology for healthcare