handbook/contributions/licensing.md

Licensing

WP-CLI is licensed under the MIT license. This document outlines WP-CLI's licensing expectations for third-party code.

Accepting third-party code into the official repository/organization

All code accepted into repositories under the official WP-CLI GitHub organization must be compatible with the MIT license. This ensures that WP-CLI can remain freely usable, modifiable, and distributable by anyone.

Bundling third-party code

When bundling third-party code directly into a WP-CLI package (i.e., copying code into the repository rather than declaring it as a dependency), the code must:

1. Be licensed under an MIT-compatible license
2. Include the original license file or header - The third-party code's license terms must be preserved
3. Maintain copyright notices - Original copyright notices must remain intact
4. Be clearly identified - It should be clear which code is third-party and where it came from

When in doubt about whether to bundle third-party code, consider using it as a dependency through Composer instead.

Depending on third-party code

Third-party packages declared as dependencies (through Composer or other package managers) must be licensed under MIT-compatible licenses. This applies to both:

• Direct dependencies - Packages explicitly listed in composer.json
• Transitive dependencies - Dependencies of your dependencies

Checking dependency licenses

Before adding a new dependency:

1. Check the dependency's LICENSE file or composer.json for license information
2. Verify that all of the dependency's own dependencies are also compatible
3. Use composer show -t to view the dependency tree with license information, or install additional tools like composer/satis to run composer licenses for detailed license auditing

Why these requirements?

These licensing requirements ensure that:

1. WP-CLI remains free and open - Users can use, modify, and distribute WP-CLI without legal concerns
2. Commercial use is permitted - Companies can use and integrate WP-CLI into their products
3. No license conflicts - All code in the WP-CLI ecosystem is legally compatible
4. Simplicity for users - Users don't need to track multiple license requirements

Questions?

If you have questions about licensing or need clarification on whether a specific license is compatible, please open an issue or contact the WP-CLI maintainers.