Cal.diy

Cal.diy is the self-hosted version of Cal.com, an open source scheduling platform designed to handle appointment booking with integrated billing automation. It lets you accept payments for bookings, set up subscription-based scheduling, and manage deposits or upfront fees directly through your own infrastructure. The tool is built for teams and individuals who want full control over their scheduling data and payment workflows.

It supports major payment gateways like Stripe for processing transactions, and integrates with popular calendar services such as Google Calendar, Outlook, and Apple Calendar. Cal.diy runs on any server with Node.js and PostgreSQL, making it platform-agnostic. The software includes features like round-robin scheduling, collective events, and customizable booking pages with payment fields. All billing logic is handled server-side, ensuring PCI compliance when configured properly.

This project is ideal for businesses that need a private, customizable scheduling system with built-in billing capabilities. It is released under the AGPLv3 license, allowing free use and modification. Cal.diy is maintained by Cal.com, the company behind the hosted Cal.com service. It has been adopted by organizations that require on-premise deployment for compliance or data sovereignty reasons.