import type { AuditEvent } from '../../types/audit-trail.js';
/**
 * Type guard for Node.js filesystem errors (ErrnoException).
 */
export declare function isNodeError(err: unknown): err is NodeJS.ErrnoException;
/**
 * Compute the canonical JSON string used for hashing an AuditEvent.
 * Excludes the `hash` field itself to avoid circular dependency.
 * CRITICAL: must stay in sync with how events are written in logger.ts.
 * If this function diverges from the write path, chain verification breaks silently.
 */
export declare function canonicalJson(event: Omit<AuditEvent, 'hash'>): string;
/**
 * Read a JSONL file and return all non-empty lines.
 * Returns an empty array when the file does not exist (ENOENT).
 */
export declare function readJsonlLines(filePath: string): Promise<string[]>;
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