About Cal.com
Cal.com is a scheduling product. A person shares a link, a guest picks a time, and both sides get the booking. Team routing and calendar connections are part of the product. Some enterprise features are under a separate licence. Read the licence files in the repository before you ship those parts.
Why it exists
Booking a meeting had become a closed widget. Teams wanted the same flow on a host they control.
Who uses it
Support, sales and professional teams that publish a booking page.
What it is used for
Appointment links and team scheduling. It is not a clinical record system.
Open source behind the product
Cal.com sells a hosted service. The AGPL application in the repository is the self-hosted product. You run a Next.js app and PostgreSQL. Calendar connections still depend on the providers you enable.
How to run it on a server
- Follow the self-hosting guide in the repository. The supported path is a container or a Node process with PostgreSQL.
- Set the secrets the guide names before you connect a calendar.
- Put HTTPS on the public URL. Booking links break if that URL changes later.
- Back up PostgreSQL. The bookings live there.
Follow the project's own guide for the version you install. Commands and file names change between releases.
How to contribute
Read the licence and the contributing guide in calcom/cal.com. A booking bug with clear steps is more useful than a wide rewrite.
- Read the project's guidelines. Open the repository and look for CONTRIBUTING, the code of conduct and the README.
- Find something to work on. Browse good first issues or all open issues. Documentation and bug reports count.
- Make a small change. Fork the repository, work on a branch, and keep the change focused.
- Open a pull request. Say what changed and why, and link the issue. See open pull requests.
Contributions are accepted under the project's own licence (AGPL-3.0). Some projects also ask you to sign a contributor agreement. A doc fix or a reproduced bug is a real contribution.
Licence: AGPL-3.0
Strong copyleft. You can use and modify it, including commercially. If you run a modified version as a network service, you must offer its source code to users under the same licence.
This is a plain-English guide, not legal advice. Read the licence in the repository before you ship it or sell a service on top of it.