Mule: Displaying HTTP Outbound Responses

I had been tasked with adding an endpoint to my Mule service for verifying other service endpoints. One of the requirements was that the endpoint be HTTP so that a browser could be used to retrieve the verification report.

Originally, when hitting the endpoint in my browser, the resulting HTML was displayed as plain text.

I resolved this by adding the HtmlResponseTransformer below:

    <http:endpoint name="VerificationEndpoint"
                 host="localhost"
                 port="28080"
                 path="services/verify"
                 method="GET"
                 synchronous="true"
                 responseTransformer-refs="HtmlResponseTransformer"/>
  
  <message-properties-transformer name="HtmlResponseTransformer">
    <add-message-property key="Content-Type" value="text/html"/>
  </message-properties-transformer>
  
  <model name="setup">    
    ...
    <service name="verify">
      <inbound>
        <http:inbound-endpoint ref="VerificationEndpoint"/>
      </inbound>
      <component>
        <spring-object bean="endpointVerifier"/>
      </component>
    </service>
    ...
  </model>

It is worth noting the HTTP Transport Documentation states that HTTP endpoints are synchronous by default, but it did appear to be the case in my experience.