Bunny DNS – A scriptable DNS platform(bunny.net)

    // Current API:
    addEventListener('dns', event => {
      event.respondWith(handleRequest(event.request));
    });

    function handleRequest(request) {
      return new TxtRecord('Hello world!, 30);
    }

    vs

    // Potential/suggested API:
    export default function handleDns(event) {
      return new TxtRecord('Hello world!, 30);
    }

    // Wrapper.js
    import handler from './user-fn.js';

    addEventListener('dns', event => {
      if (typeof handler === 'function') {
        event.respondWith(handler(event));
      } else {
        // Could support other basic types here, like
        // exporting a plain TxtRecord('Hello', 30);
        throw new Error('Only handler functions supported now');
      }
    });

  - an alternative to anycast.
  - an alternative to routing inside your app (your app could detect the IP, and have different behavior based on rules internally). This means you are always going to the same origin, which scriptable DNS would prevent, you could put things at the edge and reduce hops.