I am trying to make a call to the Excel Services REST API in a workflow to retrieve information on a workbook's charts.
The URL format is
When I use Fiddler and make the call from a browser, I see two requests to the URL. The first response returns a 401 Unauthorized but includes this in the envelope:
And then my browser sends a second (silent?) request
Authorization: Negotiate (Kerberos ticket token string)
And it gets a 200 OK and the data is presented in the browser window.
When I make the same call in a workflow, it returns a 401 Unauthorized which I logged but no subsequent request.
SharePoint 2013 and the Workflow Manager are both running with the same service account on the same machine.
What else do I need to check to get the REST call to work when invoked with a workflow?