import type { McpErrorCode } from "./types.js";
export declare class UpstreamApiError extends Error {
    readonly status: number;
    readonly upstreamCode?: string;
    constructor(status: number, upstreamCode?: string, message?: string);
}
export declare class UpstreamUnavailableError extends Error {
    constructor(message?: string);
}
export declare class UpstreamContractError extends Error {
    constructor(message?: string);
}
export declare function toMcpErrorCode(error: unknown): McpErrorCode;
export declare function errorMessageForCode(code: McpErrorCode): string;
export declare function errorHintForCode(code: McpErrorCode): string;
export declare function isRetryableErrorCode(code: McpErrorCode): boolean;