Privacy policy

Last updated: 24 October 2026

In short: MCS-Relay has no servers of its own. Everything the app does happens between your PC and Google (and playit.gg, if you turn it on). What it stores is on your PC and in the Google Drive folders of the servers you use. The developer sees your data only in a problem report you choose to send.

Who this policy is about

MCS-Relay is a free, open-source Windows app for hosting a Minecraft server in turns, with the world kept in a shared Google Drive folder. It is made by yeet30 (github.com/yeet30/MCS-Relay). "We" below means the people who make the app.

What the app uses from your Google account

When you sign in, you allow MCS-Relay to use:

Permission	What MCS-Relay does with it
Your name, email address and profile picture	Shows who is signed in, and tells the other members of a server who is hosting it and who saved each version of the world.
See, edit, create and delete your Google Drive files	Creates the "Minecraft Shared Servers" folder and the server folders in it; uploads and downloads the files of a server's world; reads the files other members uploaded; shares a server folder with the people you invite and removes members you remove; puts deleted servers in your Drive trash; keeps world backups you put in the cloud; and, only when you send a problem report, saves it in a "MCS-Relay problem reports" folder and shares it with the developer. MCS-Relay only works with server folders it created or that you joined, and with that reports folder. It does not open, list or change any other files in your Drive.

Permission

What MCS-Relay does with it

Your name, email address and profile picture

Shows who is signed in, and tells the other members of a server who is hosting it and who saved each version of the world.

See, edit, create and delete your Google Drive files

Creates the "Minecraft Shared Servers" folder and the server folders in it; uploads and downloads the files of a server's world; reads the files other members uploaded; shares a server folder with the people you invite and removes members you remove; puts deleted servers in your Drive trash; keeps world backups you put in the cloud; and, only when you send a problem report, saves it in a "MCS-Relay problem reports" folder and shares it with the developer. MCS-Relay only works with server folders it created or that you joined, and with that reports folder. It does not open, list or change any other files in your Drive.

What is stored, and where

On your PC, in the app's data folder (%APPDATA%\mcs-relay):

Your Google sign-in tokens, encrypted with Windows' own data protection.
Your settings, the folder each server uses on your PC, and what the app knows about each server's files (names, sizes and checksums), so it only transfers what changed.
A record of an upload that was interrupted, so it can be finished later.
Copies of your own files, only when you choose to keep the cloud's version over yours.
A log of what the app did (logs in the same folder, at most about 8 MB): server names, folder paths, the names and email addresses of members, and errors. It never holds your password or your Google sign-in. It leaves your PC only inside a problem report you choose to send.

In each server folder on your PC: the world backups you make, in mcs-relay-backups. They are never synced.

In Google Drive, inside each server folder (stored by Google in the Drive of whoever owns each file):

The server's files: the world, its settings and anything else in the server folder that is not on its ignore list.
A small .launcher folder with the app's own files: who is hosting right now (name and email), the players online, the server's playit.gg addresses, the list of the world's files, and the name and email of the member who saved each version.
The world backups members put in the cloud, in .launcher/backups. They count against the Drive storage of whoever uploaded them.

In a problem report, only when you send one: what you wrote, a few lines about the app and your PC (versions, Windows version, what the app was doing) and, if you leave it ticked, the end of the log above. It is saved as a text file in a "MCS-Relay problem reports" folder in your Drive and shared, read only, with the developer, who gets an email about it with your name and email address. Delete the file to take it back. You can also save a report as a file instead and send it however you like.

Apart from a problem report you send, we have no copy of any of this. There is no MCS-Relay account and no MCS-Relay server.

Who can see it

The members of a server you are in, through Google Drive sharing: the server's files and its cloud backups, and your name and email address as a member and as the host or author of a version.
The developer, only for a problem report you send, as described above. It is used only to find and fix the problem.
Google, which provides Google Drive and Google sign-in, under Google's privacy policy.
playit.gg, only if you turn it on in the app: MCS-Relay then starts the playit.gg program on your PC so friends can reach your server, under playit.gg's privacy policy.
GitHub, where the app checks for new versions and downloads them. Like any download, this shows GitHub your IP address.

We do not sell your data, use it for advertising, or collect statistics about how you use the app. The app contains no analytics or tracking.

Google API Services User Data Policy

MCS-Relay's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements. Data from your Google account is used only to provide the features described above, is never transferred except as those features need (sharing a server with its members, and a problem report you choose to send to the developer), and is never used for advertising.

Removing your data

Sign out in the app's menu: your sign-in is removed from this PC.
Take the app's access back in your Google Account under third-party apps and services.
Delete a server you own in Settings > Drive Folders: its folder goes to your Drive trash, and Google empties the trash after 30 days. Leave a server you joined to remove your access to it.
Delete a backup in the app's Backups window, and the mcs-relay-backups folder in a server folder to remove them all from this PC.
Delete a problem report from the "MCS-Relay problem reports" folder in your Drive: the developer loses access to it.
Uninstall MCS-Relay and delete the data folder above to remove everything it kept on your PC.

Security

Sign-in tokens are encrypted on your PC, and every connection to Google uses HTTPS. The app's source code is public, so anyone can check what it does.

Children

MCS-Relay is not directed at children under 13 and does not knowingly collect their data. Children's Google accounts follow the rules their parents set in Google Family Link.

Changes to this policy

When this policy changes, the new version is published on this page with a new date. Every earlier version stays visible in the project's history on GitHub.

Contact

Questions about this policy or your data: open an issue at github.com/yeet30/MCS-Relay/issues.