Posted by Tom Holman, Product Manager, Google Sheets and Josh Danziger, Software Engineer, Google Sheets
At Google, we are always working to keep our users' information safe. As part of these ongoing efforts, we will begin requiring explicit authorization when third-party sites request access to Google Sheets content via the Google Visualization API or Google Query Language.
For many developers, this change will be transparent, but others may need to make changes in order to continue reading spreadsheet data. For more details on the technical changes required, please visit the Google Charts API Documentation. We will begin enforcing these requirements on September 14, 2016.