Privacy Policy

Information we collect

Account & Google sign-in. When you sign in with Google, we receive basic profile information — your name, email address, profile picture, and Google account identifier — to create and identify your account and to enforce the owner allowlist.

Google Calendar data. With your permission, we access your Google Calendar to (a) read your calendar list (calendar names, identifiers, colors, time zones, and access roles) so you can choose which calendars to sync, (b) read events in your chosen source calendars within a configurable time window to determine when you are busy, and (c) create, update, and delete the mirror “busy block” events on your chosen target calendars. We store limited calendar metadata needed to operate the Service.

Authorization tokens. We store the OAuth access and refresh tokens Google issues so the Service can maintain your calendar connection without asking you to sign in repeatedly. These tokens are encrypted at rest and are used only to make the calendar requests described above.

Sync bookkeeping. To keep source and target calendars in sync and avoid duplicate or orphaned events, we store minimal metadata about the mirror events we create — such as event identifiers and content hashes — along with logs of sync runs.

How we use information

• Provide the core service: detect when you are busy in your source calendars and mirror those times as busy blocks on your target calendars, keeping them updated and removed as the source events change.
• Apply the per-rule privacy you choose — either copying an event's title, description, and location to the mirror, or replacing them with a generic busy label.
• Maintain the security and integrity of the Service and troubleshoot problems.

Google API Services — Limited Use

CalSync’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Specifically, we do not use Google user data for advertising, we do not sell it, and we do not transfer or use it for purposes other than providing the calendar-mirroring features you configure — except as necessary for security operations or to comply with applicable law.

How information is shared

We do not sell your personal information. CalSync is single-tenant and self-hosted, so your data is not shared with other users. We share information only:

• With service providers that operate the Service on our behalf — for example, our cloud hosting provider and our database provider — under obligations to protect the data.
• When required by law, or to protect the rights, safety, and security of our users and the Service.

Data retention and deletion

We retain your data for as long as your account is connected or as needed to provide the Service. You can revoke the Service’s access to your Google account at any time from your Google Account permissions page, or by disconnecting the account within the Service; disconnecting deletes the stored OAuth tokens for that account and stops further syncing. Mirror events already written to your calendars remain in your calendars under your control until you remove them. To request deletion of your account and associated data, contact us at hello@aentan.com.

Cookies and local storage

After sign-in, we set a single signed, HTTP-only session cookie to keep you signed in. We do not use third-party advertising or tracking cookies.

Security

We use reasonable technical and organizational measures to protect your information, including encrypted transport (HTTPS), encryption of stored OAuth tokens, and access controls that restrict the Service to accounts on the owner allowlist. No method of transmission or storage is completely secure, and we cannot guarantee absolute security.

Children

The Service is not directed to children and is not intended for use by anyone under the age required to form a binding contract in their jurisdiction.

Changes to this policy

We may update this Privacy Policy from time to time. Material changes will be reflected by updating the “Last updated” date above.

Contact

Questions about this policy or your data? Contact Aen Tan at hello@aentan.com.