Privacy Policy
Last updated: 25 October 2026
1. Who is responsible
Mark Kahlert - DualBlade Development, Atzpodienstraße 12, 10365 Berlin, Germany – e-mail: kahlertmark4@gmail.com ("we"). This policy covers the NULLCLIENT launcher, the NULLCLIENT server (friends, chat, sharing, cosmetics, shop) and this website.
2. The launcher on your computer
When you sign in with Microsoft, the launcher receives Microsoft, Xbox and Minecraft tokens. They are stored only on your computer, in your operating system's credential store, and are only ever sent to Microsoft and Mojang. We never receive your Microsoft password or your Minecraft access token. To confirm which Minecraft account you own, the launcher uses Mojang's own "join server" check: our server only learns your Minecraft name and UUID, confirmed by Mojang.
Instances, mods, worlds, skins and settings stay on your computer. When you search for content, the launcher contacts Modrinth, CurseForge (through our server, so no CurseForge key is shipped in the launcher) and Hangar with your search terms.
3. Your NULLCLIENT account
| Data | Purpose | Kept |
|---|---|---|
| Name, password (only as an Argon2 hash), Minecraft UUID and name, registration date, last time online | Your account, friends finding you, showing cosmetics in game | Until you delete your account |
| Friends, friend requests, chat messages, invites, shared modpacks, own capes, equipped cosmetics | The features you use | Until you or the other person deletes them, or your account is deleted |
| Sign-in sessions (refresh tokens, stored hashed) | Keeping you signed in | 60 days or until you sign out |
| Purchases (amount, date, item; no card data) | Null+ and cosmetics, accounting duties | As required by tax law (up to 10 years) |
| Error reports from the launcher (message, stack trace, launcher version, account if signed in) | Finding and fixing bugs | 30 days |
Legal basis: performance of the contract you enter by using the account (Art. 6(1)(b) GDPR) and, for purchase records, legal obligations (Art. 6(1)(c) GDPR); error reports and security measures are based on our legitimate interest in a working, secure service (Art. 6(1)(f) GDPR).
4. Server logs and security
For security (rate limiting, abuse protection) our server processes your IP address while handling a request. IP addresses are kept in memory for at most one hour for rate limits and appear in technical logs, which are rotated regularly. Legal basis: Art. 6(1)(f) GDPR.
5. This website
The website sets no cookies and loads no third-party trackers or fonts. To know how many people visit, each page view sends the page path and the domain of the referring site (e.g. "youtube.com") to our server, where it is counted per day. No IP address, device identifier or cookie is stored with it, so visits cannot be linked to you. Counts are kept for one year.
6. Payments
Payments are handled by Stripe Payments Europe Ltd. (Ireland). Stripe receives the data needed for the payment directly; we only receive the result (paid, amount, item). See stripe.com/privacy.
7. Other services
The launcher talks to Microsoft/Xbox and Mojang (sign-in, game files, skins), Modrinth, CurseForge and Hangar (content), Adoptium (Java), and mc-heads.net for player heads. Each is responsible for the data it receives under its own privacy policy.
8. Your rights
You can access, correct, export and delete your data, restrict or object to processing, and complain to a data protection authority. You can delete your account yourself in the launcher under Settings → NULLCLIENT account → Delete account; this removes your account, friends, chats, shared packs and capes immediately. For anything else, write to kahlertmark4@gmail.com.
9. Children
If you are under 16, please ask a parent before creating an account or buying anything.