Privacy policy

Lucas, a private calendar assistant. Effective 9 November 2026.

Who this covers

Lucas is used only by its owner, with the owner's own Google account. It is not offered to the public. This policy explains what Lucas does with the Google Calendar information the owner connects to it.

What Lucas accesses

With the owner's permission, Lucas uses the Google Calendar API to read events in the calendars the owner authorises and to create or update events when asked. It does not request access to email, contacts, files or any other Google service.

How the information is used

• To answer the owner's questions about their schedule and plan the day.
• To add or change appointments the owner explicitly asks for.
• To show upcoming events on a private status page that only the owner can reach.

Calendar information is not sold, not used for advertising, and not shared with anyone for their own purposes.

Who processes it

Lucas runs on a computer its owner controls. To produce answers, it sends the relevant calendar details, along with the owner's request, to an AI model provider (OpenAI). Replies reach the owner through Telegram, which carries the message text. These services process the information only to deliver Lucas's responses to the owner.

Storage and retention

• The Google access credentials are stored encrypted on the owner's computer.
• Lucas keeps a history of its conversations with the owner on that computer, which can include calendar details mentioned in those conversations. The history is kept until the owner deletes it.
• Calendar events themselves stay in Google Calendar. Lucas does not keep a separate copy of the calendar.

Revoking access

Access can be withdrawn at any time from the Google Account page under Third-party apps and services. Once access is removed, Lucas can no longer read or change the calendar.

Changes and contact

If this policy changes, the effective date above will change with it. Questions can be raised on the site's GitHub page.