In server you can create, read, update and delete defintions on the server by simply using the same JSON structure but changing the verb in your ajax call.

GET Read data definitons
POST Create data definitions
PUT Update data definitions
DELETE Delete the data definition

It basically works the same way as for reading, writing and updating data. You must have sufficient security rights and then you are able to change all your definiton simply by reading the old into an object,  do your changes and send it back. This means that to create a new one, the simplest it to copy an existing, change it and save it back. 

We will give a few basic samples here, but for the details there is a document for each type and a reference over all the key/value pairs supported in the definitions.