title: Is there an alternative to "type": "undefined" in JSON?
body: <p>I'm working with Amazon API Gateway. I am creating a model for an REST API.  The model gets hung up on:</p>
  <pre><code>&quot;tiers&quot;: {
      &quot;type&quot;: &quot;array&quot;,
      &quot;items&quot;: {
          &quot;type&quot;: &quot;undefined&quot;
      }
  }
  </code></pre>
  <p>The API data model uses <a href="https://datatracker.ietf.org/doc/html/draft-zyp-json-schema-04" rel="nofollow noreferrer">JSON schema draft 4</a>.</p>
  <p>The error returned is:</p>
  <blockquote>
  <p>Invalid model specified: Validation Result: warnings : [], errors :
  [Invalid model schema specified]</p>
  </blockquote>
  <p>Anyone run into this before?</p>
  <p>Things I've tried:</p>
  <ol>
  <li>Removing this property = script creates model</li>
  <li>Changing &quot;Undefined&quot; to &quot;null&quot; = script creates model</li>
  </ol>
  <p>The &quot;null&quot; seems like the right option but, I've not been able to back it up.  Some guidance and/or clarification would be greatly appreciated.</p>
  <p>Thanks,
  Todd</p>