klaws

한국어

Korean law compliance risk scanner for codebases. Scans source code for patterns that may indicate compliance risks under Korean law and maps findings to specific legal provisions. Runs as an MCP server (so AI coding assistants can scan on request) and as a standalone CLI.

Currently covers PIPA (Personal Information Protection Act), the Network Act (정보통신망법), the Credit Information Act (신용정보법), and the E-Commerce Act (전자상거래법).

Disclaimer: klaws identifies possible compliance risks for review. It does not constitute legal advice. Consult qualified legal counsel for definitive guidance.

Privacy: klaws analyzes code locally and transmits nothing. The only outbound network call is the optional --live law lookup to law.go.kr; without that flag it is fully offline. See Privacy & Security.

Quick Start

# Scan the current directory with Docker — no install needed
docker run --rm -v "$PWD":/src:ro ghcr.io/rostradamus/klaws scan /src

# ...or, if you installed the binary:
klaws scan ./my-project        # scan a directory
klaws scan ./MyService.java    # scan a single file

Related MCP server: Meridian

Installation

Docker (recommended)

No toolchain required — the image is published to GitHub Container Registry and works identically on macOS, Linux, and Windows:

# Scan the current directory (mount it read-only at /src)
docker run --rm -v "$PWD":/src:ro ghcr.io/rostradamus/klaws scan /src

# Pin a version instead of the floating latest tag
docker run --rm -v "$PWD":/src:ro ghcr.io/rostradamus/klaws:0.1.5 scan /src

Prebuilt binary

Download the archive for your platform from the latest release, extract it, and move klaws onto your PATH.

go install

go install github.com/rostradamus/klaws/cmd/klaws@latest

From source

Requirements: Go 1.23+

git clone https://github.com/rostradamus/klaws.git
cd klaws
go build -o klaws ./cmd/klaws/

Verify the install:

klaws --version

Usage

Scan

# Scan a directory (default: *.java files)
klaws scan ./src

# Scan specific file types
klaws scan ./src --pattern "*.kt"

# Text output (default is JSON)
klaws scan ./src --format text

# SARIF output (for GitHub code scanning / other tools)
klaws scan ./src --format sarif > klaws.sarif

# Fail the command (exit 1) if any finding is at or above a severity
klaws scan ./src --fail-on HIGH

# Use a custom laws file
klaws scan ./src --laws ./my-laws.yaml

Example Output

klaws scan report
Target:  ./testdata
Files:   4
Findings: 7

--- Finding 1 ---
  Detector:  PIPA-CST-001
  Risk:      HIGH
  Location:  testdata/MemberController.java:10
  Snippet:   @PostMapping("/register")
  Message:   Endpoint accepts possible personal data without apparent consent
             mechanism — may require review under PIPA Article 15
  Laws:      PIPA-15

--- Finding 2 ---
  Detector:  PIPA-ENC-001
  Risk:      HIGH
  Location:  testdata/MemberEntity.java:11
  Snippet:   private String residentNumber;
  Message:   Possible unencrypted personal identifier (residentNumber) — may
             require review under PIPA Article 24-2
  Laws:      PIPA-24-2, PIPA-29

--- Finding 3 ---
  Detector:  PIPA-LOG-001
  Risk:      MEDIUM
  Location:  testdata/UserService.java:11
  Snippet:   log.info("User registered: " + email);
  Message:   Possible personal data (email) in log output — may require review
             under PIPA Article 29
  Laws:      PIPA-29

Look Up Law Provisions

# Look up from bundled database
klaws law PIPA-15

# Fetch live text from law.go.kr
klaws law PIPA-15 --live

List Detectors

klaws detectors

[
  {
    "id": "PIPA-LOG-001",
    "name": "Personal Data Logging Risk",
    "description": "Detects log statements that may contain personal data fields",
    "related_laws": ["PIPA-29"]
  },
  {
    "id": "PIPA-ENC-001",
    "name": "Unencrypted Personal Data Risk",
    "description": "Detects personal identifier fields stored without apparent encryption",
    "related_laws": ["PIPA-24-2", "PIPA-29"]
  },
  {
    "id": "PIPA-CST-001",
    "name": "Missing Consent Check Risk",
    "description": "Detects endpoints accepting personal data without apparent consent verification",
    "related_laws": ["PIPA-15"]
  }
]

Detectors

Detectors use regex-based pattern matching. They support both English and Korean field names (e.g., email/이메일, residentNumber/주민번호, consent/동의).

MCP Server

klaws can run as an MCP server, making its scanning capabilities available to AI coding assistants.

klaws serve

Available Tools

Configuration

All clients use the same launch command: klaws serve over stdio. Use the absolute path to the binary (run which klaws, or where klaws on Windows, to find it), or just klaws if it is on your PATH. Prefer not to install anything? Use the Docker variant below — it works in any client that supports stdio MCP servers.

Claude Code — ~/.claude/settings.json:

{
  "mcpServers": {
    "klaws": {
      "command": "klaws",
      "args": ["serve"]
    }
  }
}

Or add it in one command:

claude mcp add klaws -- klaws serve

Claude Desktop — claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "klaws": {
      "command": "klaws",
      "args": ["serve"]
    }
  }
}

Cursor — ~/.cursor/mcp.json (or .cursor/mcp.json in a project):

{
  "mcpServers": {
    "klaws": {
      "command": "klaws",
      "args": ["serve"]
    }
  }
}

VS Code — .vscode/mcp.json:

{
  "servers": {
    "klaws": {
      "command": "klaws",
      "args": ["serve"]
    }
  }
}

Once connected, ask your assistant something like "scan this directory for Korean compliance risks with klaws."

Run the MCP server via Docker

No binary install needed — swap the command/args for a docker run that mounts the code you want scannable. The -i flag keeps stdin open for the stdio transport; --scan-root /src confines scans to the mounted directory:

{
  "mcpServers": {
    "klaws": {
      "command": "docker",
      "args": [
        "run", "--rm", "-i",
        "-v", "/absolute/path/to/your/project:/src:ro",
        "ghcr.io/rostradamus/klaws:latest",
        "serve", "--scan-root", "/src"
      ]
    }
  }
}

Point the assistant at paths under /src (the container-side mount), e.g. "scan /src for Korean compliance risks."

Remote (Streamable HTTP)

By default klaws serve uses stdio (local). To run it as a remote MCP server over HTTP, pass --http:

klaws serve --http :8080
# or via the published container image:
docker run --rm -p 8080:8080 ghcr.io/rostradamus/klaws serve --http :8080

The MCP endpoint is then available at http://<host>:8080/mcp (Streamable HTTP transport). Point an HTTP-capable MCP client at that URL.

Securing a remote server

klaws serve --http :8080 \
  --auth-token "$(openssl rand -hex 32)" \
  --scan-root /workspace

• --auth-token <token> — requires Authorization: Bearer <token> on every HTTP request; unauthenticated requests get 401. Can also be supplied via the KLAWS_AUTH_TOKEN environment variable. Applies to --http only.

• --scan-root <dir> — restricts scan_directory / scan_file to paths within <dir>; requests for paths outside it are rejected. (Also honored in stdio mode.)

Notes:

• --auth-token provides bearer auth but not TLS. For untrusted networks, still terminate TLS at a reverse proxy / gateway in front of klaws.

• The scan_directory and scan_file tools read the server's filesystem (the paths you pass resolve on the host running klaws). For remote scanning, run klaws where the code lives (e.g. a CI runner with the repo checked out) and set --scan-root to that checkout. The get_law_reference and list_detectors tools have no filesystem dependency.

Bundled Law Provisions

klaws ships with 40 articles across 4 Korean laws embedded in the binary (no external files needed):

PIPA (개인정보 보호법) — 10 articles

Network Act (정보통신망법) — 11 articles

Credit Information Act (신용정보법) — 10 articles

E-Commerce Act (전자상거래법) — 9 articles

Full Korean article text is included. Use --live to fetch the latest version from law.go.kr.

Privacy & Security

klaws is designed to be safe to point at private code:

• Local-only analysis. Scanning is pure static pattern-matching on files you pass in. Source code never leaves your machine — nothing is uploaded, logged remotely, or sent to any service.

• One optional outbound call. The only network request klaws ever makes is the --live law lookup (CLI) / get_law_reference with live fetch (MCP), which fetches public statute text from law.go.kr. It sends only the statute's name (e.g. 개인정보보호법, resolved from the provision you looked up) as the search query — never your code. Omit --live to stay fully offline.

• Read-only by design. klaws only reads the files it scans; it never modifies your code. Its MCP tools are annotated read-only.

• Confine the reachable filesystem. When exposing the MCP server, pass --scan-root <dir> to restrict scan_directory/scan_file to a single tree, and --auth-token when serving over --http. See Securing a remote server.

To report a vulnerability, see SECURITY.md.

Architecture

klaws scan ./src
       │
       ▼
   FileWalker ──► walks directory, matches glob pattern
       │
       ▼
  ScannerService ──► reads each file
       │
       ▼
  DetectorRegistry ──► runs all detectors on source code
       │
       ▼
    Findings ──► mapped to law provisions
       │
       ▼
   Report ──► JSON or text output

Roadmap

• More detectors: marketing-message consent (NIA-MKT-001) (done), unprotected credit information (CIA-ENC-001) (done), transaction-record retention (ECA-RET-001) (done), personal-data retention (PIPA-RET-001) (done), third-party/cross-border transfer (PIPA-XBR-001) (done)

• Multi-language: Python, JavaScript/TypeScript detection patterns

• More Korean laws: E-Commerce Act (전자상거래법) consumer protection rules (done), Network Act (정보통신망법) (done), Credit Information Act (신용정보법) (done)

• CI/CD: GitHub Action, SARIF output, severity thresholds (done)

• Configuration: custom pattern rules via config file

GitHub Action (CI)

klaws ships a composite action that scans your code and produces a SARIF report, which you can upload to GitHub code scanning so findings appear inline on pull requests and in the Security tab.

# .github/workflows/klaws.yml
name: klaws compliance scan
on: [pull_request]

permissions:
  contents: read
  security-events: write   # required to upload SARIF

jobs:
  scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - id: klaws
        uses: rostradamus/klaws@v0   # moving major tag; add `version: vX.Y.Z` below to pin the klaws binary
        with:
          path: ./src
          pattern: "*.java"
          fail-on: none      # or MEDIUM / HIGH to gate the PR

      - name: Upload SARIF
        if: always()          # upload even if fail-on tripped the step
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: ${{ steps.klaws.outputs.sarif }}

Set fail-on: HIGH (or MEDIUM) to make the check fail the PR when findings at that severity or above are present. The if: always() on the upload step ensures the SARIF is still published when the gate fails.

Releasing

Maintainers: see RELEASE.md for how to cut a release and publish to the MCP registry.

License

MIT