Checking License Compliance

What it does

When your agent uses it

• : pre-release legal review
• M&A code-audit due diligence
• Preparing an OSS attribution NOTICE file
• Switching a projects own license

Example prompts

• “check licenses”
• “license compliance audit”
• “SPDX scan”
• “/checking-license-compliance”

Requirements

• Python 3
• Compatibility (from SKILL.md): Designed for Claude Code
• Pre-approved tools (allowed-tools): Read, Bash(python3:*), Bash(pip:*), Bash(npm:*), Glob

Workflow steps

4 steps, taken from the step headings in SKILL.md.

1. 1Identify the project's own declared license
2. 2Identify policy
3. 3Run the scanner
4. 4Interpret findings

What it can do on your machine

Read from SKILL.md and the folder at commit cfae287. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Bash(python3:*)
  • Bash(pip:*)
  • Bash(npm:*)
  • Glob

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 1 file in scripts/ (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • python3
  • jq

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Designed for Claude Code

  From compatibility in the SKILL.md frontmatter.

Context cost

Checking License Compliance loads about 2.1k tokens when it runs, and up to ~5.5k if it reads all its reference files. Until then it costs about 219 tokens; SKILL.md has 756 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~219

When it runs · the whole SKILL.md, loaded when a task matches

~2.1k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~5.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NoteMentions a .env fileSKILL.md:29

  - Write(.env)

• NoteMentions a .env fileSKILL.md:30

  - Edit(.env)

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from jeremylongshore/tons-of-skills-marketplace at commit cfae287, republished under its MIT licence (© jeremylongshore). 756 words, ~2,147 tokens.

name

checking-license-compliance

description

Audit a project's dependency licenses against an explicit policy (allow-list / deny-list / review-required) and flag incompatibilities before they ship to production. Reads SPDX license identifiers from npm package manifests, Python METADATA / PKG-INFO files, and pyproject.toml; classifies each license by family (permissive, weak-copyleft, strong-copyleft, proprietary, unknown); detects copyleft contamination and SPDX-incompatible license combinations. Use when: pre-release legal review, M&A code-audit due diligence, preparing an OSS attribution NOTICE file, or switching a project's own license. Threshold: any GPL-family license in a project declaring MIT or Apache-2.0; any UNKNOWN-license package; any metadata-vs-source license mismatch. Trigger with: "check licenses", "license compliance audit", "SPDX scan", "GPL contamination check".

allowed-tools

Read, Bash(python3:*), Bash(pip:*), Bash(npm:*), Glob

compatibility

Designed for Claude Code

disallowed-tools

Bash(rm:*), Bash(curl:*), Bash(wget:*), Write(.env), Edit(.env)

version

3.30.0

author

Jeremy Longshore <jeremy@intentsolutions.io>

license

MIT

tags

security, licensing, spdx, compliance, pentest

{
  "allow": ["MIT", "BSD-3-Clause", "Apache-2.0", "ISC", "BSD-2-Clause"],
  "deny":  ["GPL-2.0-only", "GPL-3.0-only", "AGPL-3.0-only", "AGPL-3.0-or-later"],
  "review": ["MPL-2.0", "EPL-2.0", "CDDL-1.0", "LGPL-3.0-or-later"],
  "project_license": "MIT"
}

python3 ./scripts/check_licenses.py /path/to/project

Usage: check_licenses.py PATH [OPTIONS]

Options:
  --output FILE      Write findings to FILE (default: stdout)
  --format FMT       json | jsonl | markdown (default: markdown)
  --min-severity SEV (default: info)
  --policy FILE      Override default policy
  --emit-attribution  Also emit an attribution file (NOTICE.md) listing
                     every permissive-licensed dep that requires attribution

python3 ./scripts/check_licenses.py . --min-severity high --format json --output license-audit.json
jq -e '. == []' license-audit.json || { echo "License finding — legal review required"; exit 1; }

python3 ./scripts/check_licenses.py . --emit-attribution --format markdown --output NOTICE.md

mkdir -p evidence/legal/
python3 ./scripts/check_licenses.py target-acquisition-codebase/ \
    --format json \
    --output evidence/legal/license-audit-$(date +%Y%m%d).json

© jeremylongshore, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (scripts, references) in skills/.curated/checking-license-compliance of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• references/PLAYBOOK.md
• references/THEORY.md
• scripts/check_licenses.py

Open the folder on GitHubat commit cfae287