Privacy policy

Last updated: 2026-09-29

Bloomery is a launcher that runs on your own computer. There is no Bloomery account, no Bloomery server, and no analytics. We do not collect, receive or store your data. This page describes exactly what the application keeps on your machine and which third-party services it talks to when you use it.

1. What Bloomery stores on your computer

Everything Bloomery keeps is written to your local configuration directory (~/.config/bloomery on Linux and macOS, %USERPROFILE%\.config\bloomery on Windows) and to the game folder you choose.

File Location Contents and purpose
setting.json configuration directory Your game folders, the selected account, the Java list, download source, proxy and window/memory preferences.
accounts.json configuration directory Account list. Offline accounts store a name and an optional UUID. A Microsoft account stores the game name, UUID and XUID returned by Minecraft services, an OAuth refresh token, and a short-lived Minecraft access token with its expiry. The file is created with owner-only permissions (0600).
logs/latest.log configuration directory Diagnostics for troubleshooting: the command that ran, library and asset counts, download summaries. Tokens and passwords are never written to the log.
versions/, libraries/, assets/ your game folder The game itself: version manifests, the client jar, libraries, native libraries, assets and your worlds.

2. What leaves your computer, and to whom

Bloomery contacts only the services needed to install and start the game. No data is sent to the authors of Bloomery.

Service Why
login.microsoftonline.com Sign-in with the OAuth 2.0 device authorization grant, and refreshing the sign-in later. Your credentials are entered on Microsoft's page, never in Bloomery.
user.auth.xboxlive.com, xsts.auth.xboxlive.com Exchange the Microsoft sign-in for an Xbox Live token and an XSTS token.
api.minecraftservices.com Obtain a Minecraft access token and read your profile (game name, UUID) and game ownership.
piston-meta.mojang.com, piston-data.mojang.com, libraries.minecraft.net, resources.download.minecraft.net Version list, client jar, libraries, native libraries and game assets.
BMCLAPI mirror (optional) Only if you switch the download source to the mirror in your settings.
Your own HTTP proxy (optional) Only if you configure one; Bloomery sends the same requests through it.

3. What Bloomery never does

4. Deleting your data

5. Children

Bloomery is not directed at children under the age of digital consent in their country. Minecraft accounts and their use are governed by Microsoft's and Mojang's own terms.

6. Changes to this policy

This policy is versioned with the source code in the Bloomery repository; the date at the top changes when it does. Material changes are noted in the release notes.

7. Contact

Questions about this policy, or requests to delete data held about you: xiangyuanhulian@outlook.com. You can also open an issue in the project repository.

If you write to us, we receive your email address and the message, and use them only to reply. There is no mailing list and no other use.