The StartProcess web method supports impersonation, and is available as of WorkflowGen version 5.6.3). It allows an authorized user to launch a process on behalf of another user with this web method call. This feature is useful when an external application doesn’t have the user’s credentials and wants to instantiate a process on their behalf.
This impersonation feature is restricted to allowed users as defined in the ProcessesRuntimeWebServiceAllowedUsers entry in the \wfgen\ws\web.config file ).
The StartProcess web method provides a SOAP header or a GET/POST querystring parameter called ImpersonateUsername. This parameter must contain a valid WorkflowGen username, and this user must be a member of the Requester participant.