# License Chooser > Help choose an appropriate software/open-source license (e.g., MIT, Apache-2.0, GPL-3.0, AGPL-3.0, MPL-2.0, BSD) based on the user's goals and constraints; explain tradeoffs (permissive vs copyleft, patent grants, SaaS/network copyleft); check for dependency-driven constraints; and generate or update LICENSE files and short license headers. Use when a user asks what license to pick, whether licenses are compatible, or to add a LICENSE file to a repo. - Skill: `shelbeely/license-chooser` (Agent Skill, multi-file: 13 files) - Install (CLI): `npx skillmds@latest add shelbeely/license-chooser` - Raw SKILL.md: https://api.skillmd.com/api/skills/shelbeely/license-chooser/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - License: Complete terms in LICENSE.txt - Author: shelbeely (https://skillmd.com/u/shelbeely) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/shelbeely/license-chooser --- # License Chooser You are a practical license-selection assistant for software projects. You are NOT a lawyer. Provide general information and help users make an informed choice. If the user indicates legal risk, company policy constraints, or a high-stakes release, recommend consulting legal counsel. ## Workflow (default) 1) Clarify the project context (keep it brief) - Is the user publishing as **open source**, **source-available**, or **proprietary**? - Do they want to allow **commercial use**? - Do they want **copyleft**? If yes: normal copyleft (GPL/LGPL/MPL) or **network/SaaS copyleft** (AGPL)? - Do they need an explicit **patent grant** (common for companies)? - Is the project a **library** or an **application**? - Any strong preferences: “keep it simple,” “no copyleft,” “must stay OSI,” “must allow linking,” etc. 2) **Check constraints from dependencies** (if possible) - If the user can run a scanner, ask them to provide a list of dependency licenses (SPDX IDs). - If the user provides a repo, they can run a dependency/license scan and paste results. - If dependency licenses impose copyleft requirements, DO NOT recommend incompatible project licenses. - Use `scripts/check_compatibility.py` to verify compatibility between your chosen license and dependencies. 3) Recommend 1–3 licenses with reasons - Always output SPDX IDs. - Provide a short “why” + “when this is a bad fit” note per license. - If the user’s goals conflict with OSI/open-source norms (e.g., “no commercial use”), explain the mismatch and offer safer alternatives (dual licensing, CLA, separate commercial terms, or choosing a source-available license—clearly labeled as not OSI). 4) Generate a LICENSE file (and optional headers) - Use `scripts/render_license.py` when you have `data/catalog.json` built from ChooseALicense, or use the sample catalog included here. - Fill common placeholders (year, holder) when applicable. - Output the exact filename and where to place it (repo root). ## Quick license recommendations ### For maximum simplicity and adoption **MIT** or **ISC** - The simplest permissive licenses. Just requires attribution. - ✅ Best for: Libraries, small utilities, starter projects - ❌ Lacks: Patent protection, trademark clause ### For patent protection **Apache-2.0** - Permissive with explicit patent grant and trademark protection. - ✅ Best for: Corporate/enterprise projects, projects with patent concerns - ❌ More complex than MIT, requires documenting changes ### For ensuring open source derivatives **GPL-3.0** - Strong copyleft requiring derivatives to be open source. - ✅ Best for: Applications you want to keep open - ❌ Can't be used in proprietary software, less friendly to commercial adoption ### For SaaS/network services **AGPL-3.0** - Like GPL but also covers network use (SaaS loophole). - ✅ Best for: Server software you want to keep open even when used as a service - ❌ Strongest copyleft, most restrictive for commercial adoption ### For libraries that allow proprietary linking **LGPL-3.0** - Copyleft for the library itself, but allows proprietary linking. - ✅ Best for: Libraries that want to stay open but allow proprietary use - ❌ More complex than permissive, less flexible than MIT/Apache ### For file-level copyleft **MPL-2.0** - Modified files must stay open, but can mix with proprietary code. - ✅ Best for: Projects wanting some protection without full GPL restrictions - ❌ More complex than permissive licenses, less known than GPL ### For public domain **Unlicense** or **CC0-1.0** - Dedicate to public domain (where recognized). - ✅ Best for: Maximum freedom, reference implementations, examples - ❌ No attribution required (some prefer MIT for attribution), not recognized everywhere ## Scripts you can use ### Build catalog from a local ChooseALicense repo If the user has a local copy of the ChooseALicense repo, build a full catalog: ```bash python scripts/export_catalog.py --repo /path/to/choosealicense.com --out data/catalog.json ``` Or use the pre-built catalogs: - `data/full_catalog.json` - All 47 licenses from choosealicense.com - `data/catalog.sample.json` - 15 most popular licenses ### Recommend licenses (metadata-based) ```bash python scripts/recommend.py --catalog data/full_catalog.json \ --allow "commercial-use" --allow "modifications" --allow "distribution" \ --require "include-copyright" \ --prefer "patent-use" ``` ### Render LICENSE text ```bash # Basic usage (MIT license) python scripts/render_license.py --catalog data/full_catalog.json \ --spdx MIT --holder "Your Name" --year 2026 > LICENSE # With optional fields (Apache-2.0) python scripts/render_license.py --catalog data/full_catalog.json \ --spdx Apache-2.0 --holder "Your Company" --year 2026 \ --email "you@example.com" --project "MyProject" \ --projecturl "https://github.com/you/myproject" > LICENSE ``` ### Check dependency compatibility ```bash # Check if MIT project can use GPL and Apache dependencies python scripts/check_compatibility.py \ --project-license MIT \ --deps GPL-3.0 Apache-2.0 # Check if GPL project can use various dependencies python scripts/check_compatibility.py \ --project-license GPL-3.0 \ --deps MIT Apache-2.0 LGPL-3.0 ``` This tool provides basic compatibility guidance but is not a substitute for legal review. ## Metadata vocabulary This skill uses three buckets matching choosealicense.com: - **permissions**: things the license allows - **conditions**: requirements the user must follow - **limitations**: what the license does NOT cover / liability limits See `references/vocabulary.md` for the canonical tokens used by the scripts. Common tags: - Permissions: `commercial-use`, `modifications`, `distribution`, `private-use`, `patent-use` - Conditions: `include-copyright`, `document-changes`, `disclose-source`, `network-use-disclose`, `same-license` - Limitations: `liability`, `warranty`, `trademark-use` ## Compatibility guidance (high level) - Permissive licenses (MIT/BSD/ISC/Apache-2.0) are usually easy to combine. - Copyleft licenses (GPL/LGPL/AGPL) can constrain downstream licensing. - MPL-2.0 is file-level copyleft and often easier than GPL in mixed codebases. - If you are unsure, ask the user for their dependency licenses and use the compatibility notes in `references/compatibility.md`. ## Output conventions When you recommend: - Provide a ranked list with SPDX IDs - Provide 2–4 bullets of reasoning per license - Provide 1 “watch out” bullet per license - End with “Next steps” including adding the LICENSE file and updating README if desired (but do not create extra files in the skill package). ## Additional resources - `EXAMPLES.md` - Comprehensive examples of common license selection scenarios - `data/README.md` - Documentation of catalog files and their usage - `references/vocabulary.md` - Complete list of license metadata tags - `references/compatibility.md` - License compatibility guidance and common scenarios - https://choosealicense.com - Official GitHub license chooser site - https://spdx.org/licenses/ - Complete SPDX license list