Done!

Also this extension API is pretty straightforward, the element reference and parameters are right in the args so it's an easy mapping to GraphQL query strings from there. Awesome!

I was able to get a minimal version working using just this (with json-enc extension patch):

    <input
      type="text"
      name="query"
      hx-ext="json-enc"
      hx-post="http://localhost:8080/v1/graphql"
      hx-trigger="keyup changed delay:500ms"
      hx-target="#search-results"
      placeholder="<GRAPHQL QUERY TEXT HERE>"
    />
    <div id="search-results"></div>