We control all of our template updates for our custom template by way of the API within a custom program that parses metrics from files, creates hosts, host groups, and sends LLDs/metrics to Trappers. I noticed that when I attempt to modify an item or itemprototype with existing preprocessing steps that I can't delete the preprocessing steps with the item.update API method. It appears I can only update the steps. Is it possible to include the ability to remove all preprocessing steps through the API? For example, allow the ability to send in a blank entry like:

"preprocessing": [{}]

which could nullify all preprocessing steps?

I can technically workaround this by running an item.delete followed by an item.create, but since we manage items at the Template level all of the history and trends will be deleted if I later determine that I need to remove all preprocessing steps. Of course, I can also just go into the Web frontend and do it, but our code is distributed to customers who will run and manage their own instances of Zabbix and I don't want to expect them to know they have to go into the Web frontend and manually delete the preprocessing steps in this scenario.