/**
 * Extract error message from unknown error type.
 * Safely handles Error objects, strings, and other types.
 *
 * @param err - Unknown error value
 * @returns Error message string
 */
export declare function extractErrorMessage(err: unknown): string;
/**
 * Check if an error is retryable (network-related).
 * Identifies transient errors that may succeed on retry.
 *
 * @param err - Unknown error value
 * @returns true if error is retryable
 */
export declare function isRetryableError(err: unknown): boolean;
/**
 * Check if an error is an authentication error.
 *
 * @param err - Unknown error value
 * @returns true if error is auth-related
 */
export declare function isAuthError(err: unknown): boolean;
/**
 * Check if an error is a not found error.
 *
 * @param err - Unknown error value
 * @returns true if error is not found
 */
export declare function isNotFoundError(err: unknown): boolean;
/**
 * Check if an error is a permission/access error.
 *
 * @param err - Unknown error value
 * @returns true if error is permission-related
 */
export declare function isPermissionError(err: unknown): boolean;
/**
 * Check if an error is a rate limit error.
 *
 * @param err - Unknown error value
 * @returns true if error is rate-limit related
 */
export declare function isRateLimitError(err: unknown): boolean;
/**
 * Safely get error stack trace.
 *
 * @param err - Unknown error value
 * @returns Stack trace or undefined
 */
export declare function getErrorStack(err: unknown): string | undefined;
/**
 * Create a standardized error with code and metadata.
 */
export declare class AgentError extends Error {
    readonly code: string;
    readonly metadata?: Record<string, unknown>;
    readonly retryable: boolean;
    constructor(message: string, code: string, options?: {
        cause?: Error;
        metadata?: Record<string, unknown>;
        retryable?: boolean;
    });
}
/**
 * Wrap an unknown error into an AgentError.
 *
 * @param err - Unknown error value
 * @param code - Error code
 * @param metadata - Additional metadata
 * @returns AgentError instance
 */
export declare function wrapError(err: unknown, code: string, metadata?: Record<string, unknown>): AgentError;
//# sourceMappingURL=error.d.ts.map