PII Audit

Requirements

Agent: any (read-only analysis) Tools used: altimate_core_classify_pii, altimate_core_query_pii, schema_detect_pii, schema_inspect, read, glob

When to Use This Skill

Use when the user wants to:

• Scan a database schema for PII columns (SSN, email, phone, name, address, credit card, IP)
• Check if a specific query exposes PII data
• Audit dbt models for PII leakage before production deployment
• Generate a PII inventory for compliance (GDPR, CCPA, HIPAA)

Do NOT use for:

• SQL injection scanning -> use sql-review
• General SQL quality checks -> use sql-review
• Access control auditing -> finops role tools in cost-report

Workflow

1. Classify Schema for PII

Option A — From schema YAML/JSON:

altimate_core_classify_pii(schema_context: <schema_object>)

Analyzes column names, types, and patterns to detect PII categories:

• Direct identifiers: SSN, email, phone, full name, credit card number
• Quasi-identifiers: Date of birth, zip code, IP address, device ID
• Sensitive data: Salary, health records, religious affiliation

Option B — From warehouse connection:

First index the schema, inspect it, then classify:

schema_index(warehouse: <name>)
schema_inspect(warehouse: <name>, database: <db>, schema: <schema>, table: <table>)
schema_detect_pii(warehouse: <name>)

schema_detect_pii scans all indexed columns using pattern matching against the schema cache (requires schema_index to have been run).

2. Check Query PII Exposure

For each query or dbt model, check which PII columns it accesses:

altimate_core_query_pii(sql: <sql>, schema_context: <schema_object>)

Returns:

• Which PII-classified columns are selected, filtered, or joined on
• Risk level per column (HIGH for direct identifiers, MEDIUM for quasi-identifiers)
• Whether PII is exposed in the output (SELECT) vs only used internally (WHERE/JOIN)

3. Audit dbt Models (Batch)

For a full project audit:

glob models/**/*.sql

For each model:

1. Read the compiled SQL
2. Run altimate_core_query_pii against the project schema
3. Classify the model's PII risk level

4. Present the Audit Report

PII Audit Report
================

Schema: analytics.public (42 tables, 380 columns)

PII Columns Found: 18

HIGH RISK (direct identifiers):
  customers.email          -> EMAIL
  customers.phone_number   -> PHONE
  customers.ssn            -> SSN
  payments.card_number     -> CREDIT_CARD

MEDIUM RISK (quasi-identifiers):
  customers.date_of_birth  -> DOB
  customers.zip_code       -> ZIP
  events.ip_address        -> IP_ADDRESS

Model PII Exposure:

| Model | PII Columns Exposed | Risk | Action |
|-------|-------------------|------|--------|
| stg_customers | email, phone, ssn | HIGH | Mask or hash before mart layer |
| mart_user_profile | email | HIGH | Requires access control |
| int_order_summary | (none) | SAFE | No PII in output |
| mart_daily_revenue | zip_code | MEDIUM | Aggregation reduces risk |

Recommendations:
1. Hash SSN and credit_card in staging layer (never expose raw)
2. Add column-level masking policy for email and phone
3. Restrict mart_user_profile to authorized roles only
4. Document PII handling in schema.yml column descriptions

Usage

• /pii-audit -- Scan the full project schema for PII
• /pii-audit models/marts/mart_customers.sql -- Check a specific model for PII exposure
• /pii-audit --schema analytics.public -- Audit a specific database schema