phi-guard 0.1.0

HIPAA PHI scanner for CI/CD pipelines

🇺🇸 English | 🇰🇷 한국어

PHI Guard

HIPAA PHI scanner for CI/CD pipelines — like gitleaks, but for healthcare data.

The Problem

Developers working on healthcare applications accidentally commit Protected Health Information (PHI) into code repositories:

# test_patient.py
def test_create_patient():
    patient = Patient(
        name="John Doe",
        ssn="123-45-6789",           # Real SSN in test fixture
        mrn="MRN-00012345",          # Real Medical Record Number
        email="[e-mail]"
    )

This is a HIPAA violation. Fines range from $50,000 to $1,500,000 per incident.

GitHub's Secret Scanning catches API keys and passwords — but it has zero support for HIPAA's 18 PHI identifiers. PHI Guard fills that gap.

What PHI Guard Does

PHI Guard scans your codebase for 17 of 18 types of Protected Health Information defined by HIPAA:

#	PHI Type	Status
1	Names	Excluded*
2	Geographic data (ZIP codes)	Supported
3	Dates (birth, admission, etc.)	Supported
4	Phone numbers	Supported
5	Fax numbers	Supported
6	Email addresses	Supported
7	Social Security Numbers	Supported
8	Medical Record Numbers	Supported
9	Health plan beneficiary numbers	Supported
10	Account numbers	Supported
11	Certificate/license numbers	Supported
12	Vehicle identifiers (VIN)	Supported
13	Device identifiers	Supported
14	URLs	Supported
15	IP addresses	Supported
16	Biometric identifiers	N/A
17	Full-face photographs	N/A
18	Ages over 89	Supported

*Names excluded to avoid false positives. See PROJECT_GUIDE.md for details.

Use Cases

Pre-commit Hook (Fast Mode)

Block PHI before it reaches the repository. Regex-only scanning completes in under 3 seconds.

# .pre-commit-config.yaml
repos:
  - repo: https://github.com/eddykim/phi-guard
    rev: v0.1.0
    hooks:
      - id: phi-guard

CI/CD Pipeline (Full Mode)

Scan every pull request with NLP-powered detection. Catches names, locations, and other unstructured PHI that regex can't detect.

# .github/workflows/phi-guard.yml
- uses: eddykim/phi-guard-action@v1
  with:
    mode: full

Installation

pip install phi-guard

# Download the spaCy language model (required)
python -m spacy download en_core_web_sm

Usage

# Scan current directory
phi-guard scan ./

# Scan specific file
phi-guard scan ./tests/fixtures/sample.py

# Custom confidence threshold (0.0-1.0)
phi-guard scan ./ --threshold 0.7

# Exclude patterns (gitignore style)
phi-guard scan ./ --exclude "tests/*" --exclude "*.md"

# Output as JSON (for CI/CD parsing)
phi-guard scan ./ --format json

# Output as SARIF (for GitHub Security tab)
phi-guard scan ./ --format sarif

How It Works

PHI Guard uses Microsoft Presidio for PII detection, enhanced with:

• Custom recognizers for healthcare-specific patterns (MRN, insurance IDs)
• Stricter SSN detection — Presidio's default has a bug that filters out valid SSNs
• Dual-mode architecture — fast regex for pre-commit, full NLP for CI/CD
• SARIF output — integrates with GitHub Security tab

Architecture

┌─────────────────────────────────────────────────┐
│                   PHI Guard                      │
├─────────────────────────────────────────────────┤
│  CLI (Typer + Rich)                             │
│    └── phi-guard scan <path>                    │
├─────────────────────────────────────────────────┤
│  Engine                                          │
│    └── scan_text() / scan_file() / scan_dir()   │
├─────────────────────────────────────────────────┤
│  Recognizers (17 PHI types)                      │
│    ├── SSN, MRN, Phone, Email, Fax              │
│    ├── VIN, Driver's License, DEA, NPI          │
│    ├── Medicare/Medicaid, Account, Device       │
│    └── ZIP Code, URL, IP, Age over 89, Dates    │
├─────────────────────────────────────────────────┤
│  Presidio AnalyzerEngine                         │
│    ├── RecognizerRegistry                       │
│    └── SpacyNlpEngine (en_core_web_sm)          │
└─────────────────────────────────────────────────┘

Why Not Just Use Presidio Directly?

You could! But PHI Guard provides:

1. Healthcare focus — Only HIPAA PHI, not generic PII
2. CI/CD integration — Pre-commit hooks, GitHub Actions, SARIF output
3. Fixes Presidio bugs — Default SSN recognizer has score 0.05 (too low to detect)
4. Incremental scanning — Only scan changed files in PRs

Development

# Clone and setup
git clone https://github.com/eddykim/phi-guard.git
cd phi-guard
poetry install

# Download spaCy model
poetry run python -m spacy download en_core_web_sm

# Run tests
poetry run pytest

# Run the CLI
poetry run phi-guard scan ./

License

Apache 2.0

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

---

Built with Microsoft Presidio and spaCy.