// Base Message import { Instance, types } from "mobx-state-tree"; export default types .model("Message", { content: types.string, role: types.enumeration(["user", "assistant", "system"]), }) .actions((self) => ({ setContent(newContent: string) { self.content = newContent; }, append(newContent: string) { self.content += newContent; }, })); export type MessageType = Instance;