How to save HTML response from API call into a property in WSO2 Integration Studio?

I am working on a WSO2 Integration Studio project where I need to call an external API that returns an HTML response. I want to save this response into a property so I can use it later in the flow (e.g., logging or processing).

Here is the relevant part of my configuration:

<resource methods="GET" uri-template="/currentsession">
   <inSequence>
      <call>
         <endpoint>
            <http method="get" uri-template="http://example.com/api">
               <suspendOnFailure>
                  <initialDuration>-1</initialDuration>
                  <progressionFactor>-1</progressionFactor>
                  <maximumDuration>0</maximumDuration>
               </suspendOnFailure>
               <markForSuspension>
                  <retriesBeforeSuspension>0</retriesBeforeSuspension>
               </markForSuspension>
               <authentication>
                  <basicAuth>
                     <username>test</username>
                     <password>test</password>
                  </basicAuth>
               </authentication>
            </http>
         </endpoint>
      </call>

      <!-- Attempt to save response -->
      <property name="response" scope="default" type="STRING" expression="$ctx:ORIGINAL_MESSAGE"/>

      <!-- Logging the saved property -->
      <log>
         <property expression="get-property('response')" name="tt"/>
      </log>

      <respond/>
   </inSequence>
   <outSequence/>
   <faultSequence/>
</resource>

However, this setup does not store the actual HTML response in the response property as expected. The log shows it as empty or null.

What I’ve tried

• Used different property expressions:
  • $ctx:ORIGINAL_MESSAGE
  • $ctx:messageBody
  • $ctx:axis2_message_body
  • $body
• Moved the <property> mediator to various locations within the <inSequence> to check if response context changes after <call>.
• Verified that the API response is HTML (Content-Type: text/html) and correctly returns content when accessed manually.

My questions

1. How can I correctly capture the HTML response body from the <call> mediator and save it in a property?
2. Is $ctx:ORIGINAL_MESSAGE the correct expression for this use case? If not, what should I use?
3. Do I need to explicitly convert or buffer the payload to access it via a property?

Did you mean to do the below? I don't see you have assigned a value to ORIGINAL_MESSAGE.

<property name="response" scope="default" type="STRING" expression="$body"/>
<log>             
   <property expression="get-property('response')" name="tt"/>   
</log> 

Update

Add the following to the deployment.toml. Make sure the content_type is the same as the Content-Type header that comes in the response.

[[custom_message_builders]]
class = "org.apache.axis2.format.PlainTextBuilder"
content_type = "text/html"