Privacy Policy

Last updated: 18 June 2026

Folio Writer (“we”, “us”, “our”) operates the Folio Writer web app at app.foliowriter.com and the marketing site at foliowriter.com. This policy explains what personal data we collect, why, and your choices.

Who we are

Contact: folio@mb-ost.com

Data we collect

Account data: email address, display name, username, and password (stored as a secure hash). If you use Google sign-in, we receive your Google account identifier and email from Google.
User content: manuscripts, chat messages, story settings, LLM provider configuration, and encrypted API keys you choose to store.
Social data: friend connections, chat memberships, and invites.
Device data: a random device identifier stored in your browser or app, and push notification tokens if you enable notifications on Android.
Preferences: theme, language, and notification settings stored locally or on our servers.

How we use data

Provide authentication, collaboration, chat, manuscript editing, and export features.
Send optional push notifications you have enabled.
Operate and secure the service (sessions, abuse prevention, troubleshooting).

We do not sell your personal data. We do not use advertising or analytics trackers on the marketing site or in the app.

Third parties

Google: optional OAuth sign-in and Firebase Cloud Messaging for Android push notifications.
LLM providers you configure: when you chat or generate content, your messages and manuscript context are sent to the API endpoint and model you choose, using your own API keys. You are responsible for that provider’s terms and data practices.
Infrastructure: we host the service on servers we operate or control.

Cookies and local storage

We do not use marketing cookies. The app stores session tokens and preferences in your browser’s localStorage to keep you signed in and remember settings. Google sign-in may briefly set short-lived technical cookies during the OAuth redirect.

Retention

We keep your data while your account is active. When you delete your account, we delete your profile and associated data from our systems, subject to short-lived backups and logs that may persist for a limited period.

Your rights

Access and correction: update your profile in Settings.
Export: download manuscripts as DOCX from within the app.
Deletion: delete specific data in the app (manuscripts, LLM keys, friends, chat membership) or your full account. See our data deletion page for step-by-step instructions.
Questions: email folio@mb-ost.com.

If you are in the EEA/UK, you may have additional rights under applicable law (access, erasure, restriction, portability, objection). Contact us to exercise them.

Security

Traffic is encrypted with HTTPS. LLM API keys are encrypted at rest. No method of transmission or storage is 100% secure; use a strong, unique password and protect your API keys.

Children

Folio Writer is not directed at children under 13. We do not knowingly collect data from children under 13.

Changes

We may update this policy. We will post the new version on this page and update the date above.