Last updated: April 25, 2026
Zwier is operated by Wem ("we", "us", "our"). This Privacy Policy explains how we collect, use, and protect your personal data when you use the Zwier mobile application and related services.
1. Data We Collect
We collect the following types of data:
- Account information: Your email address and display name, provided during sign-up or imported from your Google account.
- Event data: Event titles, descriptions, dates, locations, and other details you create or contribute to.
- Expense data: Expense descriptions, amounts, currency, payer information, and split details that you enter within events.
- Task and itinerary data: Tasks, itinerary items, polls, and date-finder responses you create or participate in.
- Location data: Locations you add to events or itinerary items. With your permission, we may use your device's current location to suggest nearby activities. Your device location is not stored or tracked in the background.
- Push notification tokens: Device tokens used to send you event updates and reminders.
- Usage data: Anonymous, aggregated usage analytics (see "Analytics" below).
2. Authentication
We offer two ways to sign in:
- Email OTP: We send a one-time password to your email address. We store your email to manage your account.
- Google Sign-In: If you sign in with Google, we receive your name and email from Google. We do not access your Google contacts, calendar, or other Google data.
3. How We Use Your Data
We use your data to:
- Provide the Zwier service, including event planning, expense splitting, and group coordination.
- Send push notifications about event updates, task assignments, and reminders.
- Improve the app through anonymous usage analytics.
- Respond to support requests.
4. Data Storage and Security
Your data is stored in Supabase, hosted in the EU (Frankfurt region). Supabase provides encryption at rest and in transit. We use row-level security policies to ensure users can only access data for events they are members of.
5. Push Notifications
We use Expo push notification services and Firebase Cloud Messaging (FCM) to deliver notifications to your device. You can disable push notifications at any time through your device settings or within the app.
6. Analytics
We use Mixpanel to collect anonymous usage analytics. This helps us understand how features are used and where to improve the app. We do not sell analytics data. The data collected is aggregated and does not include personally identifiable information like your name or email.
7. Third-Party Services
Zwier integrates with the following third-party services:
- Supabase: Database, authentication, and file storage.
- Google: Sign-in authentication (optional).
- Expo / Firebase Cloud Messaging: Push notification delivery.
- Mixpanel: Anonymous usage analytics.
- Viator: Activity and experience suggestions. When you tap a Viator suggestion, you are taken to the Viator website or app. We earn a commission on bookings made through these links. We do not share your personal data with Viator.
8. AI Assistants (MCP)
Zwier offers an optional integration that lets AI assistants (such as Claude) read and modify your Zwier data on your behalf, via a Model Context Protocol (MCP) server at mcp.zwier.app.
- Explicit consent: Connecting an AI assistant requires you to sign in to your Zwier account and explicitly grant access on a consent screen. No assistant has access to your data without this step.
- Scope: Once connected, the assistant can read your events, members, itinerary, polls, tasks, and expenses, and can create or update events on your behalf. It cannot read events you are not a member of.
- Revocation: You can disconnect any AI assistant at any time at mcp.zwier.app/connections or from the assistant's own connector settings. Disconnecting blocks new requests immediately; an access token already issued may continue to work for up to one hour.
- Data sent to AI providers: When you ask an AI assistant a question that involves your Zwier data, the assistant fetches the relevant data from us and processes it under the AI provider's own privacy policy (for example, Anthropic's privacy policy for Claude). We don't transmit your data to AI providers ourselves; the assistant pulls only what it needs to answer your prompt.
- No training: We don't share Zwier data with AI providers for the purpose of training their models. Whether an AI provider uses your prompts and the data fetched through the assistant for its own model improvement is governed by that provider's terms.
9. Data Sharing
We do not sell your personal data to third parties. We share data only in these cases:
- With other members of events you belong to (they can see your name, RSVP status, expenses, and contributions to the event).
- With the third-party services listed above, as necessary to operate the app.
- With AI assistants you have explicitly connected (see Section 8).
- If required by law or to protect our legal rights.
10. Data Retention and Deletion
We retain your data for as long as your account is active. You can delete your account at any time from the profile screen in the app. When you delete your account:
- Your profile and personal data are permanently deleted.
- Your contributions to events (expenses, tasks, etc.) may be retained in anonymized form to maintain data integrity for other event members.
11. Your Rights (GDPR)
If you are located in the European Union, you have the right to:
- Access the personal data we hold about you.
- Request correction of inaccurate data.
- Request deletion of your data.
- Object to or restrict certain processing of your data.
- Request a portable copy of your data.
- Withdraw consent at any time (where processing is based on consent).
To exercise any of these rights, contact us at privacy@zwier.app.
12. Children's Privacy
Zwier is not intended for children under 16. We do not knowingly collect data from children under 16. If you believe a child has provided us with personal data, please contact us and we will delete it.
13. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of significant changes through the app or by email. The "Last updated" date at the top of this page reflects the most recent revision.
14. Contact Us
If you have questions about this Privacy Policy or your personal data, contact us at:
Wem
The Netherlands