anth-data-handling

# Anthropic Data Handling

## Overview

Anthropic's data policies: API inputs/outputs are NOT used for model training (commercial API). Zero-day retention is available. This skill covers PII redaction before sending to Claude and compliance patterns.

## Anthropic Data Policies

| Policy | Details |
|--------|---------|
| Training data | API data is NOT used for training (commercial API) |
| Data retention | 30-day default; 0-day available via agreement |
| Encryption | TLS 1.2+ in transit, AES-256 at rest |
| SOC 2 Type II | Certified |
| HIPAA BAA | Available for eligible customers |

## PII Redaction Before API Calls

```python
import re
import anthropic

def redact_pii(text: str) -> tuple[str, dict]:
    """Redact PII before sending to Claude, return redaction map for restoration."""
    redaction_map = {}
    patterns = [
        (r'\b\d{3}-\d{2}-\d{4}\b', 'SSN', '[SSN-REDACTED-{}]'),
        (r'\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b', 'EMAIL', '[EMAIL-REDACTED-{}]'),
        (r'\b\d{3}[-.]?\d{3}[-.]?\d{4}\b', 'PHONE', '[PHONE-REDACTED-{}]'),
        (r'\b\d{4}[- ]?\d{4}[- ]?\d{4}[- ]?\d{4}\b', 'CARD', '[CARD-REDACTED-{}]'),
    ]

    counter = 0
    for pattern, label, replacement in patterns:
        for match in re.finditer(pattern, text):
            counter += 1
            placeholder = replacement.format(counter)
            redaction_map[placeholder] = match.group()
            text = text.replace(match.group(), placeholder, 1)

    return text, redaction_map

def restore_pii(text: str, redaction_map: dict) -> str:
    """Restore redacted PII in Claude's response."""
    for placeholder, original in redaction_map.items():
        text = text.replace(placeholder, original)
    return text

# Usage
user_input = "Contact John at john@example.com or 555-123-4567"
safe_input, redactions = redact_pii(user_input)
# safe_input: "Contact John at [EMAIL-REDACTED-1] or [PHONE-REDACTED-2]"

client = anthropic.Anthropic()
msg = client.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=256,
    messages=[{"role": "user", "content": safe_input}]
)
final_output = restore_pii(msg.content[0].text, redactions)
```

## Audit Logging

```python
import json
import logging
from datetime import datetime, timezone

audit_logger = logging.getLogger("claude.audit")

def audited_request(client, user_id: str, purpose: str, **kwargs):
    """Wrap Claude API calls with audit logging."""
    # Log request metadata (never log content)
    audit_logger.info(json.dumps({
        "event": "claude.request",
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "user_id": user_id,
        "purpose": purpose,
        "model": kwargs.get("model"),
        "max_tokens": kwargs.get("max_tokens"),
    }))

    response = client.messages.create(**kwargs)

    audit_logger.info(json.dumps({
        "event": "claude.response",
        "request_id": response._request_id,
        "input_tokens": response.usage.input_tokens,
        "output_tokens": response.usage.output_tokens,
        "stop_reason": response.stop_reason,
    }))

    return response
```

## Data Handling Checklist

- [ ] PII redacted before sending to Claude API
- [ ] Audit logs capture who accessed what and when
- [ ] Logs never contain message content or PII
- [ ] Data retention policy matches your compliance needs
- [ ] Zero-day retention enabled if required (contact Anthropic)
- [ ] HIPAA BAA in place if handling PHI
- [ ] User consent obtained for AI processing
- [ ] Data deletion procedures documented

## Error Handling

| Risk | Mitigation |
|------|------------|
| PII in prompts | Pre-call redaction pipeline |
| PII in responses | Post-call output scanning |
| Audit log gaps | Centralized logging with alerting |
| Data subject access request | Searchable audit trail by user_id |

## Resources

- [Anthropic Privacy Policy](https://www.anthropic.com/privacy)
- [Anthropic Security](https://www.anthropic.com/security)
- [Usage Policy](https://www.anthropic.com/usage-policy)

## Next Steps

For enterprise access control, see `anth-enterprise-rbac`.