So, there are basicaly two functions in the Graph class. Serialize and Deserialize.
To deserialize a graph from a json string it’s actualy a matter of calling Deserialize on a Graph reference:
graph.Deserialize(string json);
The graphs are always serialized/deserialized from/to json behind the scene. Can you please clarify your question about asset bundles?
Are you encountering any issues with letting the serialization work automaticaly for you?