@SAMSAL Thank you.     For future reference.  If you ever need to figure out what the request is,  simply use NIFI UI to do the action you want while monitoring your Developer Tools.   This will expose the full request/response on any given UI action. I have filed a JIRA for this. https://issues.apache.org/jira/browse/NIFI-12503 ... View more

Hello Sam!  i am dealing with same issue as you, i see you made a question a year ago and i wonder, did you find a way to upload a Definition file from API rest ?  as you i have been tried and tired to build a process group with the file.json but documentation is not clear and does not offer an example to build the request.  i upload a file.json manually and checked the nifi-request.log and the only i see is this pettiotion " http://localhost:8081/process-groups/{id}/process-groups/upload" as "ok" did you find a way to build the body to send this request ?  thanks a lot, have a nice day.   ... View more