index.tsx

const [messageState, setMessageState] = useState<{
  messages: Message[];
  pending?: string;
  history: [string, string][];
  pendingSourceDocs?: Document[];
}>({
  messages: [
    {
      message: 'Hi, my name is Ante, ask me what you want to know!',
      type: 'apiMessage',
    },
  ],
  history: [],
});
const { messages, history } = messageState;