XML response from OData services

If you call OData services in AX 7 (Dynamics 365 for Finance and Operations), you typically get data in JSON format, like this:

{
  "@odata.context":"https://myaxinstance.cloudax.dynamics.com/data/$metadata","value":[
    {
      "name":"ElectronicPaymentTypes","kind":"EntitySet","url":"ElectronicPaymentTypes"
    },{
      "name":"ExpensePaymentDetails","kind":"EntitySet","url":"ExpensePaymentDetails"
    }
    ...
  ]
}

JSON is a simple, lightweight format with good support in many tools, but sometimes you would rather get XML. XML is by no mean deprecated – it’s more than a format; you get a whole platform with capabilities useful for validations (XML schema), querying (XPath, XQuery), transformations (XSLT) and so on. Or you simply have a component that accepts only XML and not JSON.

Fortunately OData services aren’t limited to JSON; they can return XML as well. Simply add HTTP header Accept with value application/atom+xml,application/atomsvc+xml,application/xml and you’ll start getting the same data in XML format:

<ODataServiceDocument xmlns:i="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://schemas.datacontract.org/2004/07/Microsoft.OData.Core">
  <EntitySets>
    <ODataEntitySetInfo>
      <Name>ElectronicPaymentTypes</Name>
      <Title i:nil="true" />
      <Url>ElectronicPaymentTypes</Url>
    </ODataEntitySetInfo>
    <ODataEntitySetInfo>
      <Name>ExpensePaymentDetails</Name>
      <Title i:nil="true" />
      <Url>ExpensePaymentDetails</Url>
    </ODataEntitySetInfo><ODataEntitySetInfo>
  ...
  </EntitySets>
</ODataServiceDocument>

If you use Postman, for example, this is where you can put the header:

Of course, that you get XML format doesn’t mean that you get the structure you want. You still may need to transform it to something more suitable for your purposes.