/**
 * Retry utilities, transient error detection and exponential backoff.
 */
/**
 * Check if an error is transient (retryable) vs permanent.
 * Transient: timeouts, connection resets, network issues.
 * Permanent: invalid data, unknown methods, logic errors.
 */
export declare function isTransientError(err: Error): boolean;
/**
 * Calculate exponential backoff delay with jitter.
 * Formula: baseDelay * 2^(attempt-1) + random jitter, capped at maxDelay.
 */
export declare function calcBackoff(attempt: number, baseDelay: number, maxDelay?: number): number;
