When a create_table operation is executed add an extra optional attribute called auto_increment. This attribute would dictate the hash attribute is 1. numeric & 2 will always autoincrement itself & ignore any values passed for the hash attribute on insert.
The default for this value is false if not supplied.
sample call:
{
"operation":"create_table",
"schema":"dev",
"table":"sensor",
"hash_attribute":"id",
"autoincrement":true
}