Privacy notes

1. Controller

The controller for this service is currently:

Uwe Pries
Address: Waterbergstr. 4, 81827 Munich, Germany
E-mail: up@pries.me
Phone: 0151 / 21 27 25 26

2. Purpose of the service

ValueMatch is a platform for selling second-hand physical goods via live auctions with dynamic price discovery. Sellers list items with an opening price and a floor (reserve); the price drops automatically over time until a buyer accepts, or until a previously placed standing offer fires. A short English bidding window then finalises the auction.

3. Data we process

Depending on use, we may process the following data:

• Identity keys: a locally-generated Ed25519 keypair (BIP39 mnemonic). The public key signs your actions and is visible on the public event log.
• Listings, bids, standing offers: cryptographically signed events are persisted on the backend (hash-chained event log at api.valuematch.me).
• Payment and card data: pre-authorisations and charges are handled exclusively through Stripe. We never see card numbers. We store only Stripe PaymentIntent IDs and their status.
• Profile and shipping addresses: name, e-mail and shipping addresses are stored exclusively locally on your device, if you enter them. They are never written to the event log.
• Uploaded images: listing images are stored content-addressed (SHA-256) on the backend and are publicly accessible via the URLs embedded in their listings.
• Technical logs: server logs with IP address, timestamp, HTTP method, path and status code for secure technical operation.
• Push / realtime: the ntfy.pries.me service distributes anonymous notifications about new events so clients stay in sync.

4. Public event log

Listings, bids, auction events and disputes form part of a publicly readable event log. Public keys (identities) and event payloads are visible. For standing offers placed below the current price, a per-offer ephemeral key is used so offers cannot be linked back to your identity key by outside observers.

5. Payment processing via Stripe

Card authorisations and captures are processed by Stripe Payments Europe, Ltd. Stripe's privacy notice is available at https://stripe.com/privacy. We receive only the PaymentIntent ID and its current status (e.g. requires_capture, succeeded, canceled).

6. Legal bases

Processing depends on the function and is based on:

• Art. 6 para. 1 lit. b GDPR — fulfilment of the user contract and operation of the auction;
• Art. 6 para. 1 lit. a GDPR — consent (e.g. for image uploads);
• Art. 6 para. 1 lit. f GDPR — legitimate interest in secure operation and fraud prevention.

7. Retention

Events on the public log are retained indefinitely — the log is hash-chained and retroactive modification would break its integrity. Local data on your device (profile, addresses, drafts, watchlist) remains stored until you delete it or remove the app. Stripe data is subject to Stripe's retention policy. Server logs are kept for a limited time.

8. External services

• Stripe — payment processing, card and PaymentIntent management.
• ntfy — push notifications for real-time sync between clients.
• Apple App Store / Google Play — download, distribution, optional in-app purchases.

9. Your rights

You have the statutory rights to access, rectification, erasure, restriction, data portability, withdrawal of consent and to lodge a complaint with a data protection supervisory authority. Because the event log is cryptographically chained, individual events cannot be retroactively removed; where applicable, pseudonymisation or a subsequent "revoke" event is used instead.

10. Contact

For privacy enquiries, please contact up@pries.me.

Note: this privacy policy reflects the current state of the app and backend but is not a substitute for individual legal advice. Before a public launch and any marketing, the corporate form and final third-party flows should be reviewed legally. In case of any discrepancy between this text and the German original, the German version prevails.