liccheck

What it is and what it does

liccheck is a command-line tool that audits Python project dependencies against a license compliance policy. It reads a requirements.txt or pyproject.toml file, inspects the licenses of all installed packages and their transitive dependencies, and reports violations based on three configurable strictness levels: Standard (at least one authorized license), Cautious (no unauthorized licenses even if one authorized exists), and Paranoid (all licenses must be authorized). The tool requires packages to be installed in the same Python environment where it runs, since it uses pkg_resources to access package metadata.

You define compliance rules in an INI or TOML configuration file, listing authorized licenses, unauthorized licenses, and exceptions for specific packages. The tool supports both exact string matching and regex patterns for license names. It outputs a summary of compliant packages, forbidden packages, unknown licenses, and dependency chains for violations, making it useful for legal review, CI/CD pipelines, and pre-commit hooks.

Use it for:

• Enforce corporate license policies in CI/CD by blocking builds when dependencies violate approved licenses
• Audit open-source projects before distribution to ensure compliance with GPL, MIT, Apache, or other license requirements
• Detect GPL-licensed transitive dependencies that may trigger copyleft obligations in your project
• Generate license compliance reports for legal review before shipping a product
• Prevent accidental adoption of incompatible licenses by catching violations at pre-commit time

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Scans Python project dependencies in requirements.txt or pyproject.toml and validates their licenses against a configurable policy of authorized and unauthorized licenses.

Yes. liccheck is a stable, actively maintained tool with low install friction and no security vulnerabilities. It solves a real compliance problem with minimal dependencies and clear output. Install it if your project needs to enforce license policies or audit dependencies for legal compliance.

Install

liccheck on PyPI

pip install liccheck

uv add liccheck

poetry add liccheck

Installing liccheck

Before you install

Low friction install with only two lightweight runtime dependencies (semantic-version and toml). Actively maintained as of 2026-07-20 with stable status since its 2017 release.

License in practice

Licensed under Apache Software License (permissive). No restrictions on commercial or private use.

Quickstart

pip install liccheck

Create liccheck.ini with authorized/unauthorized licenses, then:
liccheck -s liccheck.ini -r requirements.txt

Requires all packages from requirements.txt to be installed in the same Python environment; uses pkg_resources to inspect installed package metadata.

Verify before relying

• Whether regex matching performance scales well with large dependency trees
• How the tool handles packages with missing or malformed license metadata

Package facts

Evidence: liccheck-0.9.2-py2.py3-none-any.whl

Keywords: license, check, build, tool

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