Legal
Privacy Policy
What stays on your device, what leaves it when you use Miyu Sync, and the choices you have.
1. Scope and controller
This Privacy Policy explains how Miyu (“Miyu”, “we”, “us”) handles personal data in the Miyu website at miyu.avizi.co, the Miyu app, and Miyu Sync.
Miyu is the controller of the personal data described here. Contact us at support@miyu.avizi.co.
This policy does not apply to the App Store, Google Play, Stripe, RevenueCat, or other third-party services you use. Their own privacy policies apply to their processing.
2. The short version
Miyu is local-first. If you use the app without an account, your collection stays on your device. We do not receive your notes, decks, cards, or review history.
If you create an account and turn on Miyu Sync, we process account metadata and store your synced changes and backups in private cloud storage so your devices can share them.
We do not sell personal data, show advertising, or use third-party analytics or tracking.
3. Data kept on your device
The app stores your collection on your device: profiles, settings, decks, courses, cards and notes, review history, media, and local backups.
On the web and mobile apps, this uses browser or app local storage and IndexedDB. On desktop, the collection is kept in a folder such as Documents/Miyu, with automatic backups.
This data is under your control. Clearing site or app data, uninstalling the app, or losing the device can delete it. Use the export and backup features to keep a copy.
We cannot see this local data unless you choose to upload it through Miyu Sync or send it to us for support.
4. Account and sync data
When you create an account, we store your email address, a salted scrypt hash of your password, whether your email is verified, your account ID, and the account creation time.
We store session records so you can stay signed in: a hash of the session token, an optional device ID and device name (for example, “Miyu Web”), and creation, last-use, and expiry times.
We store sync metadata: generation and sequence numbers, object keys, file sizes, SHA-256 hashes, snapshot and backup records, integrity status, and storage usage.
Sync changes, snapshots, and backup ZIPs are uploaded by your device directly to a private Cloudflare R2 bucket under a prefix unique to your account. The Miyu control plane receives metadata but does not store your note contents. We do not use your content for advertising, profiling, or training AI models.
We keep billing state and RevenueCat event records needed to know whether your subscription is active.
When you contact support, we receive your email address and whatever you include in the message.
Our application logs record the request method, path, status, duration, and a random request ID for security and troubleshooting. They do not include note contents. Standard web-server logs may also include IP address and user-agent information.
IP addresses are processed in memory to apply rate limits and protect accounts. They are not stored in the application database.
5. Billing and payment data
Miyu Sync is sold through RevenueCat. Web and desktop checkout uses RevenueCat Billing with Stripe as the payment gateway. iOS and Android purchases use Apple’s App Store or Google Play billing.
Those providers collect and process payment details, billing address, and related information under their own privacy policies. We receive subscription status, plan, renewal and cancellation events, and a customer or account identifier. We do not receive your full payment card number.
We retain records needed for accounting, tax, fraud prevention, and billing disputes as required by law.
6. Email
We use SendGrid (Twilio) to send account emails such as email verification and password reset messages. SendGrid receives your email address and the contents of those messages.
We send transactional emails only. We do not send marketing email.
9. International transfers
Our providers may process data in the United States and other countries. Where required, we rely on appropriate transfer safeguards, such as standard contractual clauses offered by those providers.
10. How long we keep data
Local data stays on your device until you delete it, clear app data, or uninstall the app.
Account and subscription metadata is kept while your account is active. If you ask us to close your account, we delete it within 30 days, except records we must keep for legal, tax, or fraud-prevention reasons.
Sessions expire after 90 days and are deleted when expired or signed out. Email verification links expire after 24 hours; password reset links after 30 minutes. Expired tokens are deleted.
Sync changes and previous snapshots are pruned after about 30 days. Your current snapshot, uploaded backups, and sync metadata remain until you delete them or close your account. Deleted cloud backups are recorded so they are not re-uploaded.
Billing event identifiers are kept for 90 days to prevent duplicate processing; financial records may be kept longer as required by law.
Application logs are kept for a short period for security and troubleshooting, then deleted or rotated. Infrastructure backups may retain deleted metadata for a limited period before they are rotated out.
11. Security
We use TLS for data in transit, scrypt for password hashing, hashed session and email tokens, private object storage, and short-lived credentials scoped to your account prefix. Access to production systems is restricted.
No system is completely secure. If a breach affects your personal data, we will notify you and regulators as required by law.
Keep your password and devices secure, and sign out on shared devices.
12. Your rights and choices
Depending on where you live, you may have the right to access, correct, delete, export, restrict, or object to processing; to withdraw consent; and to complain to a data-protection authority.
You can export your collection at any time from Settings using a verified ZIP backup. You can delete local data in the app.
To close your account and delete your cloud data, email support@miyu.avizi.co from the account address. We may ask for information to verify the request. Deleting the app or clearing site data does not cancel a subscription; cancel it through Manage subscription or the store.
If you are in California, you have the rights to know, access, delete, correct, and opt out of sale or sharing. We do not sell or share personal information for cross-context behavioural advertising, so there is nothing to opt out of. We will not discriminate against you for exercising your rights.
If you live in the EEA or UK, our legal bases are: performance of a contract for account and sync services; legitimate interests for security, abuse prevention, and service reliability; legal obligation for tax and accounting; and consent where we ask for it.
We respond within the time required by applicable law. You can also complain to your local supervisory authority.
13. Children
Miyu is not directed to children under 13. Do not create an account if you are under the minimum age for digital consent in your country. If you are under 18, use Miyu only with permission from a parent or guardian.
If we learn that a child has created an account in violation of this policy, we will delete it. Contact support if you believe a child has provided personal data.
14. Changes to this policy
We may update this policy. The new version will be posted here with a new date. If a change is material, we will give notice on the website, in the app, or by email.
Continuing to use Miyu after the effective date means you accept the updated policy. If you do not agree, stop using the Service and close your account.
15. Contact
Contact support@miyu.avizi.co with “Privacy” in the subject line. Project information is also available at gitlab.com/eshahrabani/miyu.