import type { Message } from '@langchain/langgraph-sdk';
import type { MessageTuple } from './types';
type TimestampMessage = Message & {
    timestamp: number;
};
/**
 * Extracts and parses the timestamp from a message.
 * Handles different timestamp formats (number, string date).
 * Returns 0 if the timestamp is invalid or missing.
 */
export declare const getMessageTimestamp: (msg: TimestampMessage) => number;
/**
 * Checks if a message should be visible in the chat interface.
 * Filters out messages tagged as 'internal' or with empty content.
 */
export declare const isVisibleMessage: (t: MessageTuple<string>) => boolean;
export {};