import { BaseEsmsService } from './base.service';
import type { MultiChannelRequest, MultiChannelResponse } from '../types';
/**
 * Multi-Channel Service - handles multi-channel messaging
 */
export declare class MultiChannelService extends BaseEsmsService {
    private readonly endpoints;
    /**
     * Send multi-channel message
        * @param credentials Optional credentials, will use default from constructor if not provided
     */
    sendMultiChannelMessage(request: MultiChannelRequest, credentials?: {
        apiKey: string;
        secretKey: string;
    }): Promise<MultiChannelResponse>;
}