import { StreamChunk } from '../types.js';
/**
 * Best-effort extraction of a human-readable message from an unknown thrown
 * value, returning `undefined` when none can be found.
 *
 * Used by `otelMiddleware` so error reporting stays identical across chat and
 * media spans.
 */
export declare function errorMessage(err: unknown): string | undefined;
/**
 * Best-effort extraction of an error's type name (used for the `error.type`
 * metric attribute), falling back to `'Error'` when no name is available.
 */
export declare function errorTypeName(err: unknown): string;
/**
 * Convert an AG-UI RUN_ERROR event to the Error shape exposed to consumers.
 * Preserves the provider code and sanitized raw event when available, while
 * accepting the deprecated nested error payload for backward compatibility.
 */
export declare function runErrorEventToError(chunk: Extract<StreamChunk, {
    type: 'RUN_ERROR';
}>): Error;