/**
 * Optimus Authentication Client
 * Handles authentication for API requests to Optimus endpoints
 */
export declare class OptimusAuth {
    private keyId;
    private token;
    private baseUrl;
    /**
     * Create a new OptimusAuth client
     * @param envPath Path to the optimus.env file
     * @param baseUrl Base URL for the API (optional, will use OPTIMUS_ENDPOINT from env file if not provided)
     */
    constructor(envPath?: string, baseUrl?: string);
    /**
     * Load environment variables from file
     */
    private loadEnvFile;
    /**
     * Generate authentication signature
     */
    private generateSignature;
    /**
     * Get authentication headers
     * @param payload Request payload (for signature generation)
     * @returns Authentication headers
     */
    getAuthHeaders(payload?: any): Record<string, string>;
    /**
     * Make authenticated GET request
     * @param endpoint API endpoint path (will be appended to baseUrl)
     * @param params Query parameters
     * @returns Response data
     */
    get<T = any>(endpoint: string, params?: Record<string, any>): Promise<T>;
    /**
     * Make authenticated POST request
     * @param endpoint API endpoint path
     * @param data Request body
     * @returns Response data
     */
    post<T = any>(endpoint: string, data?: any): Promise<T>;
    /**
     * Download a file from an authenticated endpoint
     * @param endpoint API endpoint path
     * @param outputPath Path to save the file
     * @param params Query parameters
     */
    downloadFile(endpoint: string, outputPath: string, params?: Record<string, any>): Promise<void>;
    /**
     * Download a file from an authenticated endpoint with a specific timestamp
     * @param endpoint API endpoint path
     * @param outputPath Path to save the file
     * @param params Query parameters
     * @param timestamp Specific timestamp to use for authentication
     */
    downloadFileWithTimestamp(endpoint: string, outputPath: string, params: Record<string, any> | undefined, timestamp: string): Promise<void>;
}