Dependency License Audit

Scan project dependencies for license compatibility issues, GPL contamination, and compliance violations. Supports npm, pip, Go, Rust, and Ruby ecosystems. Use when asked to audit licenses, check license compliance, find GPL contamination, verify dependency licensing, generate license reports, or ensure open-source compliance before shipping. Also use for CI/CD license gates.

Scan project dependencies for license compatibility issues across multiple ecosystems.

Quick Start

# Basic scan (permissive policy)
python3 scripts/license_audit.py /path/to/project

# Strict enterprise scan with CI exit codes
python3 scripts/license_audit.py /path/to/project --policy permissive --ci --format markdown

# Allow weak copyleft (LGPL, MPL)
python3 scripts/license_audit.py /path/to/project --policy weak-copyleft

# Include transitive deps (npm)
python3 scripts/license_audit.py /path/to/project --include-transitive

# JSON output for tooling
python3 scripts/license_audit.py /path/to/project --format json

Supported Ecosystems

Ecosystem	Files Parsed	License Source
npm	package.json, package-lock.json, node_modules/*/package.json	Package metadata
pip	requirements.txt, Pipfile, pyproject.toml	Installed package metadata
Go	go.mod	Manual/UNKNOWN (no local metadata)
Rust	Cargo.toml	Manual/UNKNOWN (no local metadata)
Ruby	Gemfile	Manual/UNKNOWN (no local metadata)

npm and pip auto-detect licenses from installed packages. Go/Rust/Ruby report UNKNOWN unless packages are installed — review manually.

Policies

Policy	Allows	Use When
permissive (default)	MIT, Apache-2.0, BSD, ISC, etc.	Proprietary/commercial projects
weak-copyleft	+ LGPL, MPL, EPL	Library consumers (dynamic linking)
any-open	All OSI-approved	Open-source projects
custom	User-defined	Enterprise with specific requirements

For custom policy setup, see references/custom-policy.md.

Output Formats

• text — Human-readable terminal output (default)
• json — Machine-readable for CI pipelines and tooling
• markdown — Report with tables, suitable for PRs or documentation

CI Exit Codes

With --ci flag:

• 0 — No issues
• 1 — Warnings only (unknown licenses)
• 2 — Policy violations found

License Classifications

The scanner classifies licenses into categories:

• permissive — MIT, Apache-2.0, BSD, ISC, Unlicense, CC0, etc.
• weak-copyleft — LGPL, MPL, EPL, CDDL (modifications must be shared, but linking is OK)
• strong-copyleft — GPL, AGPL, SSPL (derivative works inherit the license)
• proprietary — UNLICENSED or commercial indicators
• unknown — Not recognized; manual review needed

SPDX expressions (MIT OR Apache-2.0, MIT AND BSD-3-Clause) are evaluated: OR picks most permissive, AND picks most restrictive.

Workflow

1. Run audit against project directory
2. Review violations and warnings in output
3. For each violation, follow the recommendations provided
4. Optionally create .license-policy.json for custom rules
5. Add --ci flag to CI pipeline for automated enforcement