We are ending support for the Tags Triggers API on October 14th, 2019
A small number of customers use our Tags Triggers API to track open events on emails sent with specific tags. We’re working on some more powerful features in our other API endpoints, so we are ending support for this feature, and it will be disabled on October 14th, 2019. We ask that customers who currently use this API to track opens based on tags update their applications to instead enable open tracking on a Message Stream level, or for individual messages.
Please let us know if you have any questions about this, or if we can help in any way to make the transition to stream- or message-level tracking.