/**
 * Guard Error Classes
 *
 * Standalone error hierarchy — no dependency on SDK error classes.
 * Consumers (e.g., @frontmcp/sdk) can catch GuardError and re-throw
 * as protocol-specific errors if needed.
 */
/**
 * Base error class for all guard errors.
 * Carries a machine-readable code and HTTP status code.
 */
export declare class GuardError extends Error {
    readonly code: string;
    readonly statusCode: number;
    constructor(message: string, code: string, statusCode: number);
}
/**
 * Thrown when execution exceeds its configured timeout.
 */
export declare class ExecutionTimeoutError extends GuardError {
    readonly entityName: string;
    readonly timeoutMs: number;
    constructor(entityName: string, timeoutMs: number);
}
/**
 * Thrown when a concurrency limit is reached.
 */
export declare class ConcurrencyLimitError extends GuardError {
    readonly entityName: string;
    readonly maxConcurrent: number;
    constructor(entityName: string, maxConcurrent: number);
}
/**
 * Thrown when a request waited in the concurrency queue but timed out.
 */
export declare class QueueTimeoutError extends GuardError {
    readonly entityName: string;
    readonly queueTimeoutMs: number;
    constructor(entityName: string, queueTimeoutMs: number);
}
/**
 * Thrown when a client IP is on the deny list.
 */
export declare class IpBlockedError extends GuardError {
    readonly clientIp: string;
    constructor(clientIp: string);
}
/**
 * Thrown when a client IP is not on the allow list (when default action is deny).
 */
export declare class IpNotAllowedError extends GuardError {
    readonly clientIp: string;
    constructor(clientIp: string);
}