Privacy Policy
Last updated: March 18, 2026
What Calmate Is
Calmate (“we”, “our”, “the Service”) is a calendar synchronization service that keeps your iCloud and Google Calendar events in sync. The Service is operated by the individual behind calmate.pro.
Zero-Knowledge Architecture
Calmate is built on a zero-knowledge principle. We never store the content of your calendar events (titles, descriptions, attendees, locations). The only data we process and store is sync metadata:
- Event unique identifiers (UIDs)
- Change detection tags (ETags, CTags, sync tokens)
- Content hashes (SHA-256 — irreversible, used only for change detection)
- Timestamps of last modification
Event content passes through our servers during sync but is never written to disk or any persistent storage.
Data We Store
Account Data
- Email address and name (for authentication)
- Hashed password (scrypt — we never see your plaintext password)
Calendar Credentials
- Google OAuth refresh token — encrypted at rest with AES-256-GCM
- iCloud Apple ID and App-Specific Password — encrypted at rest with AES-256-GCM
Encryption keys are stored separately from the database. Even in a database breach, credentials cannot be decrypted without the master key.
Subscription Data
- Stripe customer ID and subscription status
- We do not store credit card numbers — Stripe handles all payment data
Sync Logs
- Sync status (success/error), event count, duration, timestamps
- Error messages (technical only, never event content)
Third-Party Services
- Google — OAuth for calendar access (Google Privacy Policy applies)
- Apple iCloud — CalDAV access (Apple Privacy Policy applies)
- Stripe — Payment processing (Stripe Privacy Policy applies)
Data Retention
Account data is retained while your account is active. Upon deletion:
- All credentials are immediately deleted
- Sync state and logs are deleted within 24 hours
- Stripe data is retained per Stripe's retention policy
Your Rights
You can at any time:
- Export your sync configuration
- Disconnect Google or iCloud accounts
- Delete your account and all associated data
Security
- All connections use TLS (HTTPS)
- Credentials encrypted with AES-256-GCM at rest
- Database not exposed to the internet
- Rate limiting on authentication endpoints
Contact
For privacy questions, email contact@calmate.pro.