What should I use to detect PII leakage in generated responses?

To detect PII leakage in generated responses, use a PII detection + policy enforcement layer rather than relying on the model alone.

Good options:

• Microsoft Presidio
  Open-source, widely used for detecting and anonymizing PII in text. Good starting point for names, emails, phone numbers, addresses, IDs, etc.

• Google Cloud DLP / AWS Comprehend / Azure Purview
  Managed cloud services with stronger enterprise support, compliance features, and easier scaling.

• Custom rules + regex + allowlists
  Useful for high-precision detection of known formats like credit cards, SSNs, API keys, account numbers, and internal identifiers.

• LLM-based classifiers
  Helpful for contextual PII that regex misses, but should be paired with deterministic checks because they can be inconsistent.

Recommended approach:

1. Run generated output through a PII scanner
2. Block or redact matches
3. Log and review flagged cases
4. Add prompt/instruction filters to reduce leakage upstream
5. Test with adversarial prompts and synthetic PII examples

If you want a practical default:

• Start with Presidio
• Add regex detectors for sensitive formats
• Use a policy engine to decide whether to redact, reject, or escalate

If you tell me your stack (Python, Java, cloud provider, etc.), I can suggest a concrete implementation.