Hi Rolf, 1. As of version 6.6.0 (released June 27th 2016), you can now consume REST-webservices natively in a Mendix-microflow, the tutorial you refer to is written in 2015. It is a stable release, so yes, you can use this new activity. 2. Along with this new activity, a JSON-import/export mapping functionality is released in version 6.6.0. I do not encounter the same problem: inside a Exportmapping item, I can select which attributes should be exported. If you need different attributes for another POST-webservice, I suggest you use also another Exportmapping. 3. For published REST-services you do need the REST Services Module indeed. And as far as I know, you only have one key-attribute to identify an already existing object, but you can create your own handler in a microflow. What do you need exactly? 4. Did you try to create your own microflow?