import { BaseApi } from './base-api';
import { SmsRequest } from '../models/sms-request';
import { SmsResponse } from '../models/sms-response';
import { ProxyConfig } from '../models/proxy-config';
/**
 * SmsApi class provides methods to interact with the SMS API.
 */
export declare class SmsApi extends BaseApi {
    /**
     * Creates an instance of SmsApi.
     * @param username - The API username.
     * @param password - The API password.
     * @param proxyConfig - Optional proxy configuration.
     */
    constructor(username: string, password: string, proxyConfig?: ProxyConfig);
    /**
     * Sends SMS messages (single or multiple).
     * @param smsRequest - The SMS request payload.
     * @returns Promise resolving to SmsResponse.
     * @throws ErrorResponse if the API call fails.
     */
    sendSms(smsRequest: SmsRequest): Promise<SmsResponse>;
    /**
     * Cancels a scheduled SMS campaign.
     * @param campaignId - The ID of the campaign to cancel.
     * @returns Promise resolving to a success message.
     * @throws ErrorResponse if the API call fails.
     */
    cancelScheduledMessage(campaignId: number): Promise<string>;
    /**
     * Calculates the number of SMS credits required for the given message.
     * @param message - The message content.
     * @returns The number of SMS credits required.
     */
    calculateSmsCredits(message: string): number;
}