wp-calypso

What Calypso is

Calypso is the WordPress.com dashboard reimplemented as a single page application powered by the WordPress.com REST API. It is built for reading, writing, and managing all of a user's WordPress sites in one place. On the back end it uses a light Node and Express server, and on the front end it uses React, Redux, wpcom.js, and a number of other libraries, replacing the older PHP driven admin interface with a modern web application.

Running it locally

The getting started path requires git, Node, and yarn. After cloning the repository, you add 127.0.0.1 calypso.localhost to your local hosts file, run yarn and then yarn start from the root directory, and open calypso.localhost:3000 in a browser. More detailed installation, troubleshooting, and contribution instructions live in the docs directory, and the project promises a welcoming experience for contributors of varied backgrounds and experience levels.

Community and licensing

Calypso has adopted the Contributor Covenant code of conduct and welcomes pull requests, suggestions, bug reports, and questions. Security vulnerabilities are reported through Automattic's security program and a HackerOne bug bounty rather than public issues. The code is licensed under the GNU General Public License version 2 or later, and the August 2026 snapshot shows 12,637 stars, 2,026 forks, and 3,232 open issues.

Editorial conclusion

The application is GPL-2.0 licensed and records 12,637 stars with 2,026 forks as of August 2026. It is the React and Redux based admin interface that powers the logged in areas of WordPress.com.