k "GraphiQL", "/javascript_client/graphiql_subscriptions" %},
        {% internal_link "urql", "/javascript_client/urql_subscriptions" %}, or custom JavaScript.
      </p>
    </div>
    <div class="hero-feature">
      <h2>Going Beyond</h2>
      <p>
        Customize your GraphQL API:
        <ul>
          <li>{% internal_link "Language tooling", "/language_tools/visitor/ %} for manipulating GraphQL documents</li>
          <li>{% internal_link "Type system extensions", "/type_definitions/extensions/ %} 