Get row identifier from DataExtension

Question

I use an undocumented preview API to render email preview.

POST /guide/v1/emails/<emailID>/dataExtension/<DE-Key>/rows/<rowId>/preview?kind=html

To render preview I need to specify exact DataExtension and its row

The problem is with getting an identifier of this row - none of the APIs I know return row Id

I try with SOAP for DataExtensionObject - but it never returns neither ObjectId nor CustomerKey - they are always null, and it doesn't allow to specify these properties for retrieve

I also try undocumented GET /data/v1/customobjectdata/key/<DE-Key>/rowset but it also doesn't return id's

When I generate preview from the browser I see that UI goes to some internal endpoint:
/fuelapi/data-internal/v1/customObjectData/<DE-Key>?showKey=true
identifiers from this endpoint work for preview, but I get 401 Unauthorized for s2s credentials when I call /data-internal/ endpoint

Is there any other way to get a row identifier or point to a row for preview in another way?

Answer 1

There is a hidden field _CustomObjectKey which is used in AmpScript, this field may also be requested for DataExtensionObject:

Thanks to Jonas Lamberty for a hint!

Request:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Header>
    <fueloauth>secret</fueloauth>
  </soap:Header>
  <soap:Body>
    <RetrieveRequestMsg xmlns="http://exacttarget.com/wsdl/partnerAPI" xmlns:ns2="urn:fault.partner.exacttarget.com">
      <RetrieveRequest>        
        <ObjectType>DataExtensionObject[D9F88129-A6AA-4A55-B625-C807BB0EFE14]</ObjectType>
        <Properties>_CustomObjectKey</Properties>
        <Properties>modulename</Properties>
        <Properties>display</Properties>
        <Properties>country</Properties>
        <Properties>subjectline</Properties>
        <Properties>language</Properties>
      </RetrieveRequest>
    </RetrieveRequestMsg>
  </soap:Body>
</soap:Envelope>

Response:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" ... >
   <soap:Header> ... </soap:Header>
   <soap:Body>
      <RetrieveResponseMsg xmlns="http://exacttarget.com/wsdl/partnerAPI">
         <OverallStatus>OK</OverallStatus>
         <RequestID>3d71cc49-30e7-4432-97e1-8a31fb0680cf</RequestID>
         <Results xsi:type="DataExtensionObject">
            <PartnerKey xsi:nil="true"/>
            <ObjectID xsi:nil="true"/>
            <Type>DataExtensionObject</Type>
            <Properties>
               <Property>
                  <Name>_CustomObjectKey</Name>
                  <Value>13</Value>
               </Property>
               <Property>
                  <Name>modulename</Name>
                  <Value>NamedModule</Value>
               </Property>
               ...
            </Properties>
         </Results>
         <Results xsi:type="DataExtensionObject">
            <PartnerKey xsi:nil="true"/>
            <ObjectID xsi:nil="true"/>
            <Type>DataExtensionObject</Type>
            <Properties>
               <Property>
                  <Name>_CustomObjectKey</Name>
                  <Value>42</Value>
               </Property>
               <Property>
                  <Name>modulename</Name>
                  <Value>Subject</Value>
               </Property>
               ...
            </Properties>
         </Results>
      </RetrieveResponseMsg>
   </soap:Body>
</soap:Envelope>