Microsoft Presidio
Data protection and anonymization for PII in LLM pipelines
Verdict
Best open-source PII detection and anonymization library. Detect-and-replace SSN, emails, credit cards before sending to LLMs. Critical for GDPR/HIPAA compliance in RAG.
Other Guardrails & Safety
- Anthropic Constitutional AIStable
Principle-based self-improvement for harmlessness and helpfulness
- Azure AI Content SafetyProduction
Microsoft's content moderation API for text and images
- Guardrails AIStable
Add input/output validation and safety rails to LLM calls
- Lakera GuardStable
Real-time prompt injection and jailbreak protection API
- Llama Guard 3Experimental
Meta's fine-tuned safety classifier for prompt and response screening
- NeMo GuardrailsExperimental
NVIDIA toolkit for programmable guardrails via Colang language

