interface AuditCommitment {
  /** Message ID this commitment refers to */
  messageId: string;
  /** Sender agent ID */
  sender: string;
  /** Recipient agent ID */
  recipient: string;
  /** SHA256 hash proving message existence */
  hash: string;
  /** Timestamp of commitment generation */
  timestamp: number;
  /** Attestation level for this communication */
  attestationLevel: 'bilateral' | 'unilateral' | 'none';

  // Unilateral-specific fields (present only for A2A-only recipients)
  /** Direction of unilateral interaction */
  direction?: 'outbound' | 'inbound';
  /** URL of the A2A-only agent */
  a2aAgentUrl?: string;
  /** Whether the A2A agent was reachable */
  reachable?: boolean;
  /** HTTP status code if a response was received */
  httpStatus?: number;
  /** Correlation ID linking outbound request to inbound response */
  correlationId?: string;
}