Index: app/controllers/attachments_controller.rb
===================================================================
--- app/controllers/attachments_controller.rb   (revision 13333)
+++ app/controllers/attachments_controller.rb   (working copy)
@@ -21,7 +21,7 @@
   before_filter :delete_authorize, :only => :destroy
   before_filter :authorize_global, :only => :upload

-  accept_api_auth :show, :download, :upload
+  accept_api_auth :show, :download, :upload, :thumbnail

   def show
     respond_to do |format|