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"]
}