Privacy Policy
Your mental health data is deeply personal. We built Circadia with privacy as the foundation, not an afterthought.
Overview
Circadia ("we," "our," or "us") is operated by Swan Media Co. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use our mobile application and web service (collectively, the "Service").
Our Core Privacy Principles:
- Zero-Knowledge Architecture: Your data is encrypted on your device before it ever reaches our servers. We cannot read your data.
- Local-First Design: The app works fully offline. Sync is optional and additive.
- No Content Analytics: We do not analyze the content of your mood logs, journal entries, or health data.
- No Advertising: We do not sell your data or show you ads. Ever.
Data We Collect
Information You Provide
- Account Information: Email address (hashed for authentication lookup), passkey credentials
- Mood Data: Episode state, intensity, symptoms, timestamps, and notes (encrypted)
- Journal Entries: Title, body text, voice memos, and photos (encrypted)
- Medication Data: Medication names, dosages, schedules, and adherence logs (encrypted)
- Preferences: App settings, notification preferences, baseline configurations (encrypted)
Health Data (with your permission)
With your explicit consent, we access the following data from Apple HealthKit:
Critical (Sleep Data)
- • Sleep duration and stages
- • Time in bed vs. asleep
- • Bedtime and wake time
- • Sleep consistency patterns
High Priority
- • Heart rate variability (HRV)
- • Resting heart rate
- • State of Mind entries
Standard
- • Step count
- • Workout data
- • Active calories
- • Mindful minutes
Why We Prioritize Sleep
Research shows sleep disruption is one of the strongest predictors of bipolar episodes. We treat sleep as a primary indicator, not an afterthought.
Automatically Collected Information
- Device Information: Device type, operating system version, app version (for compatibility)
- Sync Metadata: Timestamps, device IDs, sync status (non-sensitive, not encrypted)
- Crash Reports: Anonymous crash data to improve app stability (no personal content)
Zero-Knowledge Encryption
We cannot read your data. This is by design.
All sensitive data (mood entries, journal content, health correlations, preferences) is encrypted on your device using keys derived from your password. The encryption happens before data ever leaves your device.
How It Works
- 1Your password is processed with Argon2id (a memory-hard key derivation function) to create a Key Encryption Key (KEK)
- 2A random Data Encryption Key (DEK) is generated and encrypted with your KEK
- 3All your data is encrypted with the DEK using AES-256-GCM encryption
- 4Only encrypted blobs are transmitted to and stored on our servers
What this means: Even if our servers were breached, attackers would only find encrypted data they cannot decrypt. Even if we were legally compelled to provide your data, we could only provide encrypted blobs—we don't have the keys to decrypt them.
How We Use Your Data
Because of our zero-knowledge architecture, we have very limited ability to "use" your data. Here's what we can and cannot do:
What We Do
- • Store encrypted data blobs for sync
- • Authenticate your account (hashed email)
- • Send account-related emails (magic links)
- • Monitor service health and uptime
- • Analyze anonymous crash reports
- • Process subscription payments
What We Cannot Do
- • Read your mood entries or journals
- • Access your health data content
- • Analyze your mental health patterns
- • Profile you based on symptoms
- • Sell or share your health information
- • Decrypt your data under any circumstances
Data Sharing & Third Parties
We do not sell, rent, or trade your personal information. Period.
We may share limited information with the following categories of service providers:
- Cloud Infrastructure: Cloudflare (hosting, CDN) — they store only encrypted blobs
- Payment Processing: Stripe — for subscription management (we never see full card numbers)
- Email Service: Resend — for transactional emails (magic links, account notifications)
- Error Monitoring: Anonymous crash reporting only (no personal content)
Legal Requests
If we receive a legal request for your data, we can only provide encrypted blobs and basic account metadata (email hash, account creation date). We cannot provide decrypted content because we do not have the decryption keys.
Your Rights
Depending on your location, you may have the following rights under GDPR, CCPA, or other privacy laws:
Right to Access
Request a copy of your data. Export features are built into the app—you can export all your data at any time.
Right to Correction
Correct inaccurate data directly within the app. You have full control over your entries.
Right to Deletion
Request deletion of your account and all associated data. We will purge all encrypted blobs.
Right to Portability
Export your data in standard formats (CSV, PDF) designed for sharing with healthcare providers.
Right to Restrict Processing
Use the app in offline-only mode. Your data never leaves your device.
Right to Object
Opt out of any optional data processing. Most processing happens locally on your device anyway.
To exercise any of these rights, contact us at privacy@circadia-app.dev. We will respond within 30 days.
Data Retention
- Active Accounts: Your encrypted data is retained as long as your account is active.
- Account Deletion: Upon request, we delete all encrypted data within 30 days. Backup systems may retain encrypted blobs for up to 90 days before complete purge.
- Inactive Accounts: Accounts inactive for 2+ years may be flagged for deletion with advance notice.
- Local Data: Data stored locally on your device remains under your control and is not automatically deleted.
Children's Privacy
Circadia is not intended for children under the age of 13. We do not knowingly collect personal information from children under 13. If you are a parent or guardian and believe your child has provided us with personal information, please contact us at privacy@circadia-app.dev.
For users between 13-18, we recommend parental guidance when using mental health tracking applications.
Contact Us & Policy Changes
If you have questions about this Privacy Policy or our data practices, contact us at:
Swan Media Co.
Email: privacy@circadia-app.dev
We may update this Privacy Policy from time to time. We will notify you of any material changes by posting the new Privacy Policy on this page and updating the "Last updated" date. For significant changes, we will also send you an email notification.
If you're in crisis or need immediate support, please reach out: