import type { IFIXParser } from '../IFIXParser.ts';
import type { Message } from '../message/Message.ts';
/**
 * Handles the first message in a FIX session.
 * This function validates that the first message is a Logon message.
 * If not, it sends a Logout message and closes the connection.
 *
 * @param {IFIXParser} parser - The FIX parser instance handling the session
 * @param {Message} message - The first message received in the session
 * @returns {boolean} - Returns true if the first message is a Logon, false otherwise
 */
export declare const handleFirstMessage: (parser: IFIXParser, message: Message) => boolean;