What is Thunderbird Appointment used for?

Thunderbird Appointment lets people book time on your calendar through a shareable booking page, with a dashboard for availability and bookings. It is a good fit for letting clients book meetings on your calendar.

Is Thunderbird Appointment open source?

Yes. Thunderbird Appointment is open source under the MPL-2.0 licence. Its source code is on GitHub at thunderbird/appointment and is written mainly in Python.

Is Thunderbird Appointment free?

Yes. Thunderbird Appointment is open source, so the software itself is free to use. A managed cloud version is also available.

Can I self-host Thunderbird Appointment?

Yes. Thunderbird Appointment can be self-hosted on your own server or infrastructure.

What is Thunderbird Appointment an alternative to?

Thunderbird Appointment is an open-source alternative to Calendly, SavvyCal, Microsoft Bookings and Acuity Scheduling. Other open-source alternatives to Calendly include Cal.diy, Easy!Appointments and Someday.

Is Thunderbird Appointment actively maintained?

Yes. The most recent commit to Thunderbird Appointment was on 24 September 2026. The project has 553 stars on GitHub.

Thunderbird Appointment: open-source alternative to Calendly

About Thunderbird Appointment

Thunderbird Appointment is an open-source scheduling tool for inviting others to grab times on your calendar. The goal is to make booking appointments as easy as possible: you set your availability, share a link, and attendees pick a slot on a bookers page. It is part of the Thunderbird Pro family of services.

Subscribers get a dashboard for setting up availability, managing bookings and adjusting general settings. The supported way to build and run it is with Docker, which starts five containers: the backend, the frontend, PostgreSQL, Redis and Mailpit for testing email, with OpenAPI documentation available from the backend. A flag controls whether first-time registration is allowed to create the initial admin user, and an allow list defines admin accounts. Simple password-based authentication is meant only for development and testing.

The backend is written in Python and the project is licensed under MPL-2.0. A hosted service is available at appointment.tb.pro, and feedback and support are handled through a mailing list called Topicbox.

Key features

Public booking page for attendees
Availability setup
Booking management dashboard
Docker-based installation
OpenAPI documentation
Admin allow list

Good fit for

→Letting clients book meetings on your calendar
→Self-hosted alternative to scheduling services

Built with: Python
Tags: scheduling; appointments; calendar; booking; python; docker; thunderbird; self-hosted

Thunderbird Appointment: questions and answers

What is Thunderbird Appointment used for?: Thunderbird Appointment lets people book time on your calendar through a shareable booking page, with a dashboard for availability and bookings. It is a good fit for letting clients book meetings on your calendar.
Is Thunderbird Appointment open source?: Yes. Thunderbird Appointment is open source under the MPL-2.0 licence. Its source code is on GitHub at thunderbird/appointment and is written mainly in Python.
Is Thunderbird Appointment free?: Yes. Thunderbird Appointment is open source, so the software itself is free to use. A managed cloud version is also available.
Can I self-host Thunderbird Appointment?: Yes. Thunderbird Appointment can be self-hosted on your own server or infrastructure.
What is Thunderbird Appointment an alternative to?: Thunderbird Appointment is an open-source alternative to Calendly, SavvyCal, Microsoft Bookings and Acuity Scheduling. Other open-source alternatives to Calendly include Cal.diy, Easy!Appointments and Someday.
Is Thunderbird Appointment actively maintained?: Yes. The most recent commit to Thunderbird Appointment was on 24 September 2026. The project has 553 stars on GitHub.