Field	Type	Required	Description
expressions	array of objects	+	An array of expressions
expressions[index].name	string	+	An expression name
expressions[index].code	string	–	Expression code
expressions[index].value	number / string / boolean / object	–	An expression value. It will reflect the current expression state and changes if any item referred to by the expression change. One of value and error should be present.
expressions[index].error	array of strings	–	Expression errors. The error appears if the expression components change. Successfully created expressions do not have an error field. A failed expression can be saved with errors, in which case both value and error fields are possible.
expressions[index].valueType	string	–	Required for typed expressions; optional, by default is empty.
expressions[index].metadata	any json	–	Metadata of an expression. Can be of valid JSON object. If null, should not be shown.
expressions[index].variable	boolean	–	If true, the expression is a variable. Variables cannot use the params collection.