import { HttpClient } from '../http';
/**
 * Base service class for all eSMS services
 */
export declare abstract class BaseEsmsService {
    protected http: HttpClient;
    protected defaultApiKey?: string;
    protected defaultSecretKey?: string;
    constructor(http: HttpClient, defaultApiKey?: string, defaultSecretKey?: string);
    /**
     * Add authentication to request payload
     * Can use provided credentials or fall back to default
     */
    protected withAuth<T extends object>(payload: T, apiKey?: string, secretKey?: string): T & {
        ApiKey: string;
        SecretKey: string;
    };
    /**
     * Create URL search params with auth
     * Can use provided credentials or fall back to default
     */
    protected createAuthParams(params: Record<string, string | number | undefined>, apiKey?: string, secretKey?: string): URLSearchParams;
}