Thank you for sharing this. But after a scan through the docs I am not sure if the Dns server can fetch the response from an api.

Sorry for not making the question clear. I want this kind of flow:

The dns server gets a query. The dns server makes that query to a web api using a get request like /resolve/myawesomedomain.com The web api responds { "A": 10.10.10.10 } The dns server responds with that A record

I don't know existing tools for this kind of a task, but I think it wouldn't be that hard to write your own solution.