VIAaaS

VIAaaS - ViaVersion as a Service - Standalone ViaVersion proxy

Address generator: https://jo0001.github.io/ViaSetup/aspirin

Public instances: https://github.com/ViaVersion/VIAaaS/wiki/List-of-Public-Instances

Videos

Offline mode tutorial: https://youtu.be/lPdELnrxmp0

How does it work?

• ViaVersion, ViaBackwards and ViaRewind translates the connections to backend server.
• VIAaaS auth page stores account credentials in the player's browser local storage.
• It uses a CORS Proxy for calling Mojang APIs.
• Account credentials aren't sent to VIAaaS instance by default.
• The web page receives and validates the join game request from VIAaaS instance.

Setting up server instance

Download: GitHub Actions (needs to be logged into GitHub) or JitPack

How to download and start VIAaaS server:

curl -Lf --output VIAaaS-all.jar "https://jitpack.io/com/github/ViaVersion/VIAaaS/master-SNAPSHOT/VIAaaS-master-SNAPSHOT-all.jar"
java -jar VIAaaS-all.jar

• Requires Java 17
• Default Minecraft: via.localhost with port 25565
• Default HTTPS: https://localhost:25543/

How to create a public server

• You need a DNS wildcard pointing to VIAaaS instance, like *.example.com -> 192.168.123.123.
• Configure the hostname in the config
• Open the Minecraft port (25565)
• The HTTPS page needs a valid SSL certificate, you can use a reverse proxy like Apache (with a Let's Encrypt certificate).

Usage for players

You'll need to specify which server you want to connect through address parameters added as prefix in via.localhost or via web page (default https://localhost:25543/).

Offline mode:

• Connect to mc.example.net.via.localhost

Online mode:

Web login:

• Go to VIAaaS auth webpage (default is https://localhost:25543/)
• Listen to the username A (you'll use it to connect to the VIAaaS instance).
• Add the account B (you'll use it in backend server).
• Keep the page open
• Connect with your account A to mc.example.com._u(account B).via.localhost
• Approve the login in the webpage

Web login via token caching:

• Open the web page and save your account in your browser
• Send your access token to the instance. After that you can close the page.
• Connect to mc.example.com.via.localhost with the account you sent the token.

Fabric/Forge client:

• Install OpenAuthMod in your client.
• Join the server: mc.example.net.via.localhost
• Approve the login

Address options

Example address:

• server.example.net._p25565._v1_12_2._of._uBACKUSERNAME.via.example.com
• server.example.net.v_1_8.via.example.com

Address parts:

• You can use (option)_(value) too, like p_25565.
• server.example.net: backend server address
• _p: backend port
• _v: backend version (protocol id or name, replace . with _) . AUTO is default (with 1.8 as fallback).
• _o: true to force online mode in frontend, false to force offline mode in frontend. If not set, it will be based on backend online mode.
• _u: username to use in backend connection (default is front-end username)
• via.example.com: instance address (defined in config)

WARNING

• VIAaaS may trigger anti-cheats, due to block, item, movement and other differences between versions. USE AT OWN RISK.
• Take care of browser local storage. Check for XSS vulnerabilities on your domain.
• Check the security of CORS proxy, it will be used for calling to Mojang API.

FAQ

Accounts

Why to use an online webpage for online mode?:

• It's easier to maintain in that way, because providing login via chat requires encoding and decoding more packets, which reduces maintainability.
• It allows your account password and token to be kept with you.

How to use Microsoft Account?:

• If you're an administrator of the instance, edit config/web/js/config.js (default is in the jar) and configure your Azure Client ID and your domain whitelist.

Connection

How to use IPv6?:

• The hostname parser currently doesn't support direct IPv6, but you can use a DNS name with https://sslip.io/

I'm getting a DNS error/"Unknown host" while connecting to via.localhost

• Try configuring via.localho.st as hostname suffix instead

How to use with Geyser?

• Set the parameters in Geyser's address field:

  remote:
    # The IP address of the remote (Java Edition) server
    address: 2b2t.org._v1_12_2.via.localhost

• If you are using GeyserConnect: connect to a publicly available VIAaaS instance, like mc.example.com._v1_8.via.example.net as a Java Edition server.

Can you support more versions / Is there some alternative?

• See ViaProxy

Can I customize the files of HTTP server?

• Add files to config/web/ directory