/** Shared provider terminal codes across native and SDK transports. */
export declare function classifyProxyFailureCode(code: string | undefined): {
    status: number;
    retryable: boolean;
} | {
    status: undefined;
    retryable: boolean;
} | {
    status: number | undefined;
    retryable: undefined;
};
/** Read explicit SDK/API failure evidence without guessing from free-form text.
 * Bounded traversal covers common error/cause/data and JSON response envelopes. */
export declare function getProxyUpstreamFailure(error: unknown): {
    status: number;
    code: string | undefined;
    retryable: boolean | undefined;
    message: string | undefined;
} | undefined;