That’s exactly what I want to do too.
Where are tags in the database?
I’ve poked in data explorer and can’t find “tag” in it anywhere. badge-query-request-received-x-likes-in-topic-containing-specific-tag asks the same question, but the answer worked another way.
Why badges for tags?
Others say that badges for posting is ripe for abuse, but I have students create a topic with a certain tag to indicate that they have completed an assignment. I want to create a badge so that they can see that they have “turned in” the work, and then another to indicate that it was “good” (presumably with a “like” until I get a you-did-it-right plugin written).