Greetings all,
First, we would like to apologize for the disruption and confusion that some API consumers have experienced over the last 24 hours.
We are able to confirm that there was indeed a change deployed which altered the behavior of the OAuth APIs for the /oauth/token endpoint, which removed support for HTTP GET requests. This change was applied with the best intentions to ensure the best security practices are followed for the Blizzard OAuth APIs, however, we realize that this also negitively impacted a number of consumers. We failed to communicate this change ahead of time, and for that we deeply apologize.
This change hase since been reverted, and requests to /oauth/token using HTTP GET should continue to work as they previously did. Our intention is to once again disable HTTP GET requests to the /oauth/token endpoint at a later date, and we ask consumers to please account for this in your integrations by migrating to using HTTP POST. Please keep an eye out for further communication at a later date regarding migrating.
We would like to extend our thanks to everyone who reported issues, and to everyone who assisted others with debugging & troubleshooting efforts here on the forums and through other channels.
Thank you for all of your feedback, reports, and collaboration.