Coss
Coss is a free, open-source UI component library built with React, Next.js and Tailwind CSS. Coss.com/ui is the official design system of Cal.com. It has 10,669 GitHub stars and is released under the AGPL-3.0 license. A live demo is linked from this page.
Get started
Copy the files into a new folder with degit (no git history), or clone the repository with git.
npx degit cosscom/coss my-ui
cd my-ui
npm install # then run the dev script from the READMEgit clone --depth 1 https://github.com/cosscom/coss.git my-uiSources: GitHub docs on template repositories, degit.
About Coss
coss.com/ui is the official Cal.com Design System. This repository contains multiple products and applications that make up the coss.com ecosystem:
Built with
- React
- Next.js
- Tailwind CSS
- shadcn/ui
- TypeScript
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What is Coss?
Coss is a free, open-source UI component library built with React, Next.js and Tailwind CSS. Coss.com/ui is the official design system of Cal.com. It has 10,669 GitHub stars and is released under the AGPL-3.0 license. A live demo is linked from this page.
How do I use Coss?
Copy the files into a new folder with npx degit cosscom/coss my-ui (no git history), or fork the repository on GitHub. Then follow the README for the install and dev commands.
Can I use Coss for commercial projects?
It depends on the AGPL-3.0 license. CC-BY licenses need visible attribution, GPL and AGPL licenses require sharing your changes under the same license, and other licenses have their own terms. Read the LICENSE file in the repository before shipping a client project.
Is Coss maintained?
The repository's most recent commit was on Oct 7, 2026. appsgit only lists templates from repositories with a commit in the last six months.