Prism Relay

Prism Launcher, relay edition

Play Minecraft through a relay.

A build of Prism Launcher that sends all of its network traffic through a relay server, so it never connects to Mojang or Microsoft directly. Download it, enter the relay address and your access token, and you're set.

Download Read the setup guide

Download

Most people only need the Mac app. The Windows download is for running your own relay.

Prism Launcher for Mac

Apple silicon (M1 or newer) · macOS 12 or later · about 35 MB

The launcher itself. This is what you use to play.

Download for Mac (.dmg)

Does not run on Intel Macs. After downloading, see step 1 for the one-time approval macOS asks for.

Advanced

Relay server for Windows

Windows 10 or later, 64-bit · about 8 MB

Only needed if you want to host a relay on your own computer. You don't need it to connect to this one.

Download for Windows (.exe)

Windows SmartScreen may say it protected your PC. Choose More info, then Run anyway.

Set up the Mac app

Four steps. You'll need an access token from the person who shared this page.

  1. Install and open it

    Open the downloaded .dmg file and drag Prism Launcher into your Applications folder. Then open it from there.

    macOS will refuse the first time. It says it can't verify the app, because the app isn't notarized by Apple. That's expected. To allow it once:
    1. Open System Settings and go to Privacy & Security.
    2. Scroll down to the message about Prism Launcher being blocked and click Open Anyway.
    3. Enter your Mac's password, then click Open.
    After that it opens normally. On older macOS versions, right-click the app and choose Open instead.

  2. Open the settings

    In the launcher, press ⌘ , (Command and comma), or choose Settings from the Prism Launcher menu. Click Services in the list on the left. The Relay Server box is at the top of that page.

  3. Enter the address and your token

    Fill in the two fields of the Relay Server box:

    First field: address
    https://relay.qctechnicalconsulting.com Type it exactly like this: starting with https://, with no port number and no slash on the end.
    Second field: token
    Paste the access token you were given. It's a long string of letters and numbers. Treat it like a password, and don't post it anywhere.

    Click OK. The change applies straight away, so there's no need to restart.

  4. Sign in and play

    Go to Settings → Accounts and add your Microsoft account. The launcher shows a short code and asks you to enter it at microsoft.com/link. That page opens in your web browser, which doesn't use the relay, so if your network blocks it, type the code on your phone instead.

    Then create or open an instance and launch it. The first launch downloads Minecraft and its libraries through the relay, so it can take a few minutes.

Good to know

What the relay can see

Everything the launcher sends goes through the relay, so whoever runs it can see which sites the launcher contacts, and your Microsoft and Minecraft sign-in tokens pass through it. Only use a relay run by someone you trust, and only use this one if you're comfortable with that.

What doesn't go through it

The game itself runs as a separate program, so joining an online multiplayer server doesn't use the relay. Neither does the sign-in page you open in your browser.

It only allows known sites

The relay only forwards to a list of approved websites. If something fails to download, the owner may need to add that site to the list.

Troubleshooting

The Mac says the app can't be opened or can't be verified

Follow the approval steps in step 1: System Settings → Privacy & Security → Open Anyway. If your Mac is managed by a school or an employer, that option may be turned off, and you'd need to ask whoever manages it.

Requests fail with "Host unreachable" or a timeout

The launcher can't reach the relay. Check that the address is exactly https://relay.qctechnicalconsulting.com, then open it in your browser with /healthz on the end. If the page shows the word unauthorized, the relay is up and the problem is on your side. If it doesn't load, the relay may be offline, or your network may be blocking it.

I get "unauthorized" or a wrong token error

The token is wrong, or it has been changed. Copy it again with nothing extra at the start or end, and paste it into the second field. If it still fails, ask for a new one.

A download fails and the error mentions a site I don't know

The relay refused that site because it isn't on its approved list. Tell the person who runs the relay which site it was, and they can allow it. Downloads of Java and of some mods come from sites that may need adding.

Every request fails and mentions relay-not-configured.invalid

The address or token in Settings is empty or mistyped. The launcher blocks everything on purpose in that case, so nothing is sent without going through the relay. Re-enter both fields.

The game won't start because a library file is damaged

A library that didn't download properly can be left behind. In Finder, press ⇧ ⌘ G and open ~/Library/Application Support/PrismLauncher/libraries. Move the damaged file named in the error to the Trash, then launch again so the launcher downloads it fresh.

Run your own relay

Optional. For people who want to host their own relay instead of using this one.

  1. Download prism-relay.exe above and run it on a Windows PC that stays on. Your browser opens its admin page.
  2. Point a domain name at your home internet connection, and forward TCP ports 443 and 80 on your router to the PC.
  3. On the admin page's Server tab, enter the domain, keep Automatic selected, and press Start relay, then Check certificate.
  4. Copy the address and token from the Connect tab into the launcher.

The full guide, with troubleshooting for each step, is in the project's relay documentation.