agent-chat-ui/agent/types.ts

import { MessagesAnnotation, Annotation } from "@langchain/langgraph";
import {
  RemoveUIMessage,
  UIMessage,
  uiMessageReducer,
} from "@langchain/langgraph-sdk/react-ui/server";

export const GenerativeUIAnnotation = Annotation.Root({
  messages: MessagesAnnotation.spec["messages"],
  ui: Annotation<
    UIMessage[],
    UIMessage | RemoveUIMessage | (UIMessage | RemoveUIMessage)[]
  >({ default: () => [], reducer: uiMessageReducer }),
  timestamp: Annotation<number>,
  next: Annotation<"stockbroker" | "tripPlanner" | "generalInput">(),
});

export type GenerativeUIState = typeof GenerativeUIAnnotation.State;