With the Remote Control API, you can create, update or delete you flags.
The flag architecture is the following :
{
"name": "<NAME>",
"type": "<TYPE>", // string, boolean, number, array or object
"source": "manual", // manual or codebase_analyser
"description": "<DESCRIPTION>",
"default_value": "a",
"predefined_values": ["a", "b"]
}