Privacy policy
Who is responsible
Patrik Schiller, Czech Republic operates https://mcto3d.com and is the controller of the personal data described here. Questions and requests: support@mcto3d.com.
What this service does not collect
Worth stating first, because it is unusual: your Minecraft worlds and the 3D models you create never reach our server. Loading a world, selecting a region, building the mesh and generating the STL file all happen inside your browser. We cannot see your worlds or your models, and we do not store them.
We also run no analytics, no advertising and no tracking of any kind, and no third-party scripts load when you visit.
The one exception is opt-in: pages that show a demonstration video display a still image, and the YouTube player only loads if you press play. If you do, YouTube (Google) receives the request and may set cookies, as it would on any site embedding a video. Choose not to press play and nothing from Google is contacted at all.
What we store, and why
| Data | Why | Kept for |
|---|---|---|
| Email address | Identifies your account; receives confirmation and password-reset messages | Until you delete the account |
| Password, stored only as a scrypt hash | Signing in. The password itself is never stored and cannot be recovered from the hash | Until you delete the account |
| Login sessions (a hash of the cookie token) | Keeping you signed in, and letting a session be revoked | 30 days, or until you sign out |
| Confirmation codes and password-reset tokens (hashes only) | Confirming your address; resetting a forgotten password | 24 hours / 1 hour, then deleted |
| Download records (a timestamp per export) | Showing you your own download history | Until you delete the account |
| Addresses that bounced or reported us as spam | So we never email them again | Indefinitely — see below |
| Server logs, which include IP addresses | Operating the service, diagnosing faults, and rate limiting to prevent abuse | A short period at our hosting provider; we do not extend it |
Legal bases
- Performance of a contract — your account, signing in, and providing downloads.
- Legitimate interests — keeping the service available and secure: rate limiting, server logs, and the suppression list described below.
The suppression list, and why it outlives an account
If an email to you bounces permanently, or you report one of our messages as spam, we record that address so we never send to it again. That record remains even if the account is deleted, because deleting it would allow the same address to be emailed again — which is precisely what the record exists to prevent, and what protects other people from mail they did not want. It is kept for no other purpose, and is never used for marketing.
Who else processes your data
- Amazon Web Services — hosting (Frankfurt, EU) and sending our email through Amazon SES. Your email address is processed to deliver confirmation and reset messages.
- Neon — the managed PostgreSQL database holding the data in the table above. The database is located in the EU (Frankfurt); the provider is established in the United States.
Both act only on our instructions, under their own data processing agreements, which incorporate the European Commission's standard contractual clauses for any processing that takes place outside the European Economic Area: AWS GDPR centre and Neon's data processing agreement. Neon publishes its own list of sub-processors.
Cookies and local storage
We set one cookie: session, which keeps you signed in. It is
strictly necessary to provide an account, so it does not require consent, and it is not used to
track you. It is httpOnly (unreadable by scripts), SameSite=Lax and sent
only over HTTPS.
The editor also saves your own display preferences — field of view, shadows, graphics quality, key bindings and similar — in your browser's local storage. If you dismiss the notice telling you the editor needs a desktop, that choice is kept in session storage instead and is forgotten when you close the tab. Nothing in either store leaves your device.
We set no other cookies. Pressing play on an embedded video hands you over to YouTube, which sets its own — described above.
Your rights
Under the GDPR you may request access to your data, correction, erasure, restriction of processing, objection to processing based on legitimate interests, and portability. Two of these are self-service:
- Erasure — your account page has a "Delete account" option, which removes your account, sessions, download history and any pending tokens immediately.
- Access — the account page shows everything we hold about you.
For anything else, email support@mcto3d.com. You also have the right to complain to the Czech data protection authority, Úřad pro ochranu osobních údajů (uoou.gov.cz).
Security
Passwords are hashed with scrypt and a per-user random salt. Session, confirmation and reset tokens are stored only as SHA-256 hashes, so a copy of the database would not yield anything usable to sign in with. All traffic uses HTTPS, and the connection to the database is encrypted.
Changes
If this policy changes we will update the date at the top. Because the service is young and still growing, that is likely to happen; if a change affects you and we have your confirmed email address, we will tell you.