title: How to set representation for specific format on Json Serializer used by MicroProfile Rest Client?
body: <p>How to set representation for specific format on Json Serializer used by MicroProfile Rest Client?</p>
  <p>I have a service that requires a year-month input, formated as ISO 8601 &quot;YYYY-MM&quot;. The server-side is working, and the response is correctly formatted, but implementation is Resteasy.</p>
  <p>I'm using MicroProfile Rest Client, and entity attribute is defined as <code>java.util.YearMonth</code>.</p>
  <p>The request is sent with serialized JSON year-month attribute represented as an object when I want it to be a formatted string.</p>
  <p>Already tried annotating attribute with <code>JsonFormat</code>, <code>JsonbDateFormat</code> and <code>@Schema</code>, with same results.</p>
  <p>Also tried adding Jackson Provider (ContextResolver), which works for the server-side, but no changes on the client-side.</p>
  <p>Code snippet of testes annotations:</p>
  <pre class="lang-java prettyprint-override"><code>import com.fasterxml.jackson.annotation.JsonFormat;
  import org.eclipse.microprofile.openapi.annotations.media.Schema;
  import javax.json.bind.annotation.JsonbDateFormat;
  
  @JsonFormat(shape = Shape.STRING, pattern = &quot;yyyy-MM&quot;)
  @JsonbDateFormat(value = &quot;yyyy-MM&quot;)
  // Next one I'm guessing. Can't find docs for this.
  @Schema(type = SchemaType.STRING, implementation = YearMonth.class, pattern = &quot;yyyy-MM&quot;)
  private YearMonth referencia;
  </code></pre>
  <p>Environment:</p>
  <ul>
  <li>Wildfly 21</li>
  <li>Java SE 11</li>
  <li>microprofile-rest-client-api:2.0</li>
  <li>microprofile-openapi-api:2.0</li>
  </ul>