In a sandboxed sharepoint 2013/office 365 workflow, I'm trying to query a list (using REST) in the root web, for a value. If the workflow fires in the root web, I get the value. If you call it in a subweb it returns a HttpStatus of unauthorised.
Following these two articles : http://msdn.microsoft.com/en-us/library/jj822159.aspx, and http://www.fabiangwilliams.com/2014/06/19/gotcha-on-sharepoint-designer-workflows-in-app-step/ it will work if you manually apply the permissions to workflow 'app'.
This method is impractical, as our users will be creating their own sites, and having them register workflows, and writing chunks of xml in to a textboxx may undermine usability :). How can I ensure that the workflow context has permissions to access the root web? Is it possible to get an accesstoken and apply that to the HttpSend item? If so how?