import type { ErrorCode, RPCError } from './types.js';
/**
 * RPC Exception class for structured error handling
 */
export declare class RPCException extends Error {
    readonly code: ErrorCode | string;
    readonly data?: any;
    constructor(code: ErrorCode | string, message: string, data?: any);
    /**
     * Create exception from JSON error object
     */
    static fromJSON(error: RPCError): RPCException;
    /**
     * Convert exception to JSON-serializable format
     */
    toJSON(): RPCError;
}
/**
 * Helper function to create RPC exceptions
 */
export declare function createError(code: ErrorCode | string, message: string, data?: any): RPCException;
/**
 * Type guard to check if error is an RPC exception
 */
export declare function isRPCError(error: any): error is RPCException;
/**
 * Mark an error this client raised for a no-responder status it saw itself.
 * A handler that passes such an error on reports `upstream unavailable`
 * instead, so its caller does not take it for a missing responder of its own.
 *
 * Internal: client.ts and handler.ts use it.
 */
export declare function markLocalNoResponders<E extends Error>(error: E, subject: string): E;
/**
 * The subject of a no-responder error from markLocalNoResponders(),
 * undefined for any other value.
 *
 * Internal: handler.ts uses it.
 */
export declare function localNoRespondersSubject(error: unknown): string | undefined;
/**
 * Check whether an error is a NATS "no responders" error — i.e. nobody is
 * subscribed to the requested subject (the target service is not running).
 */
export declare function isNoRespondersError(error: unknown): boolean;