License Compliance

License Compliance

Purpose: Guide for ensuring LGPL-3.0 license compliance when developing Chrono Dawn mod.

How it works: This skill is automatically activated when you mention tasks related to:

• Adding new dependencies to the project
• Checking license compatibility
• Preparing for mod distribution
• Reviewing third-party licenses
• Adding license headers to source files

Simply describe what you want to do, and Claude will reference the appropriate guidance from this skill.

Project License

Project License: LGPL-3.0 (GNU Lesser General Public License v3.0)

CRITICAL: This project is licensed under LGPL-3.0. All contributions and modifications must comply with LGPL-3.0 terms.

LGPL-3.0 Key Requirements

1. Copyleft

Derivative works must remain LGPL-3.0 (or compatible license)

2. Source Code Availability

Source code must be made available to users

3. License Notice

Include LGPL-3.0 license notice in distributions

4. Dynamic Linking

Mods using this code via dynamic linking (normal Minecraft mod usage) can use any license

Example: A mod that depends on Chrono Dawn as a library can be proprietary

5. Static Linking/Modification

Modified versions or statically linked code must be LGPL-3.0

Example: Forking Chrono Dawn and modifying source code requires LGPL-3.0 licensing

Adding Dependencies

License Compatibility Check

When adding dependencies, verify license is LGPL-3.0 compatible:

Compatible Licenses (can use):

• MIT License
• Apache 2.0 License
• BSD License (2-clause, 3-clause)
• LGPL-3.0 or LGPL-2.1
• Public Domain

Incompatible Licenses (avoid):

• Creative Commons Non-Commercial (CC-BY-NC)
• Proprietary licenses
• GPL-3.0 (only if statically linking; dynamic linking is OK)

Documentation Requirement

Document all third-party licenses in THIRD_PARTY_LICENSES.md:

Required Information:

1. Project name
2. Version
3. Developer/Organization
4. License type
5. Project URL
6. License URL

Where to Find License Info:

• GitHub repository LICENSE file
• Maven Central / CurseForge / Modrinth project page
• Project website
• Source code headers

License Headers in Source Files

Optional but Recommended:

Add license headers to core implementation files:

Files Requiring Headers:

• Core implementation files in common/src/main/java/com/chronodawn/
• Platform-specific entry points in fabric/ and neoforge/

Header Template:

/*
 * This file is part of Chrono Dawn.
 *
 * Chrono Dawn is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Chrono Dawn is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Chrono Dawn. If not, see <https://www.gnu.org/licenses/>.
 */

When to Add:

• New core class files
• Significant modifications to existing files
• Files intended for distribution

Distribution Checklist

Before distributing the mod (CurseForge, Modrinth, GitHub Releases):

• Verify LICENSE file contains LGPL-3.0 text
• Update THIRD_PARTY_LICENSES.md with all dependencies
• Check all dependencies are LGPL-3.0 compatible
• Confirm source code is publicly available (GitHub repository)
• Include license notice in mod metadata (fabric.mod.json, neoforge.mods.toml)
• (Optional) Add license headers to core source files

License Change History

2025-12-27: Changed from "All Rights Reserved" to LGPL-3.0 (T601-T608)

Rationale: Patchouli dependency removed (T706), enabling FOSS (Free and Open Source Software) licensing

Common Questions

Q: Can I use Chrono Dawn as a library in my proprietary mod?

A: Yes. Dynamic linking (normal Minecraft mod dependency) allows any license. Your mod does not need to be LGPL-3.0.

Q: Can I fork Chrono Dawn and sell it?

A: Yes, but your fork must remain LGPL-3.0. Users have the right to the source code. Selling LGPL software is allowed, but buyers can redistribute it freely.

Q: Can I add a GPL-3.0 dependency?

A: Yes, if it's dynamically linked (modImplementation). Avoid statically linking (shadowing/bundling) GPL dependencies.

Q: Do I need to add license headers to every file?

A: No, it's optional but recommended for core files. The LICENSE file is sufficient for basic compliance.

Q: Can I contribute to Chrono Dawn without agreeing to LGPL-3.0?

A: No. All contributions must be LGPL-3.0 compatible. By contributing, you agree to license your code under LGPL-3.0.

Resources

• LGPL-3.0 Full Text: https://www.gnu.org/licenses/lgpl-3.0.en.html
• GNU Licenses Explained: https://www.gnu.org/licenses/licenses.html
• SPDX License List: https://spdx.org/licenses/

Last Updated: 2026-01-16 Maintained by: Chrono Dawn Development Team