ViaFabric

Client-side and server-side ViaVersion implementation for Fabric

Allows the connection to/from different Minecraft versions on your Minecraft client/server (LAN worlds too)

If you are using the latest Minecraft version and care about the gameplay being more enjoyable/functional, you may want to check ViaFabricPlus out. See the differences between ViaFabric and ViaFabricPlus.

This mod can be installed on:

• Minecraft 26.x+ versions
• 1.14.4 – 1.21.11
• 1.8.9 / 1.12.2 using the Fabric Loader.

For each year, there is a versioned branch named after that year (for example, ver/26.x). Each yearly branch contains all 26.x releases published during that year.

Additional version branches

• ver/1.14-1.21 supports 1.14.4, 1.15.2, 1.16.5, 1.17.1, 1.18.2, 1.19.4, 1.20.6, 1.21.11
• ver/1.8-1.12 supports 1.8.9 and 1.12.2

Anti cheat integration

ViaFabric now supports custom payload sending to transmit player protocol version data to the server when installed on the client side. This allows servers to retrieve a player's protocol version via plugin messages, which can be useful for anti-cheat checks and version-dependent logic. For more details on how to use this feature, see the Player Details Protocol wiki.

Dependencies

Dependency	Download
(Bundled) ViaVersion	https://viaversion.com/
(Bundled) Cotton Client Commands (MC 1.14-15)	https://jitpack.io/#TinfoilMC/ClientCommands
Fabric API	https://modrinth.com/mod/fabric-api

Note: ViaVersion is designed for Vanilla Minecraft servers. It probably will not work with modded registry entries or registry synchronization (fabric-registry-sync mod).

ViaVersion

How can I install ViaBackwards/ViaRewind/ViaAprilFools?:

• Just drop them into mods folder. Make sure you are using versions compatible with the ViaVersion version you are using.

What versions can ViaVersion, ViaBackwards, ViaRewind and ViaAprilFools translate?:

• With ViaVersion: Your server can accept newer versions. Your client can connect to older versions.

• Adding ViaBackwards (and optionally ViaRewind): Your server can accept older versions. Your client can connect to newer versions.

• Adding ViaAprilFools: Your server can accept April Fools versions.

  Note: When using ViaFabric for versions older than 1.17, you need Java 8 builds

• Server-side: See https://viaversion.com/

• Client-side:

	1.8.x	1.9.x	1.10-1.20.x	1.21.x
1.14.4-1.20.6 clients	✓	✓	✓	⟲
1.21.11 client	✓	✓	✓	✓

✓ = ViaVersion ⟲ = ViaBackwards ⏪ = ViaRewind

Note: 1.7.x is not supported in ViaFabric - 1.9.x, 1.10.x, 1.11.x, and 1.13.x may cause problems when visiting such servers in client-side mode.

Can ViaVersion, ViaBackwards and ViaRewind support snapshots?:

• Check https://viaversion.com/donate for getting early access to snapshots. You can use the preview ViaVersion builds with ViaFabric by putting them in the mods' folder. During Minecraft updates there will be usual a branch on this repository with the updated ViaFabric.

Alternatives

Client-side:

• ViaForge: Clientside Implementation of ViaVersion for Forge.
• ViaFabricPlus: Fabric mod for the latest Minecraft version with QoL fixes and enhancements to the gameplay.
• multiconnect: Discontinued Fabric mod for connecting to older versions: down to 1.11 (stable) and 1.8 (experimental).

Server-side:

• ViaVersion: Plugin for Velocity and Paper/Bukkit (and optionally also Sponge/BungeeCord).
• ProtocolSupport: Discontinued Bukkit plugin for older client versions (down to 1.4.7).

Standalone proxy:

• ViaProxy: Standalone ViaVersion proxy with ViaBackwards, ViaRewind and ViaLegacy, allowing you to connect to a wide range of versions (down to classic versions) with your modern client (1.7.2+). Supports online mode.
• VIAaaS: Standalone ViaVersion proxy with ViaBackwards and ViaRewind, allowing you to connect without a mod installed on your client. Supports online mode.
• DirtMultiversion: Discontinued Proxy allowing to connect down to Beta 1.3 with newer Minecraft client versions.

Cool things to try:

• Geyser: Plugins, Fabric mod and a standalone proxy for allowing Bedrock Edition on Java Edition servers.
• PolyMc: Fabric mods which translates modded items and blocks, allowing vanilla to connect using resource packs.

Commands

Commands:

• There are 3 server-side alias /viaversion, /vvfabric and /viaver, and a client-side command /viafabricclient for Minecraft 1.14+ (OP permission level 3 is required for these commands, received by Entity Status Packet)

Configs

Configuration:

• ViaVersion configuration is available at .minecraft/config/viafabric/viaversion.yml
• ViaFabric configuration is at .minecraft/config/viafabric/viafabric.yml

How can I disable client-side ViaFabric?:

• You can disable it in the menu or by setting global protocol version to -1 (this will keep per-server translations still enabled)

How to use protocol detection?:

• For using globally, set the protocol to AUTO or -2. For using in a specific server: ddns.example.com._v-2.viafabric
• The protocol detector will try to ping with the client native protocol version, differently than using -1 version, which may detect the native server version.

How can I set the version for specific servers?:

Suffix Style

• Append ._v(VERSION).viafabric after the host, before any port.
  • All dots (.) in a given version must be replaced with underscores (_).
• Examples:
  • minigame.example.com._v1_8.viafabric
  • native.example.com._v-1.viafabric
  • auto.example.com._v-2.viafabric

Prefix Style

• Add viafabric.v(VERSION); before the address.
• Examples:
  • viafabric.v1.8;minigame.example.com
  • viafabric.v-1;native.example.com
  • viafabric.v-2;auto.example.com

ViaFabricPlus

Does it work with ViaFabric:

• No, ViaFabric cannot be used with ViaFabricPlus.

Differences with ViaFabricPlus:

	ViaFabric	ViaFabricPlus
Can be installed on	Multiple client/server versions with fabric	Latest client-side version with fabric
Objectives	Simply implement ViaVersion	Implements ViaVersion with client-side fixes to version changes
How does it work?	Modifying packets at network code	Modifying client code more deeply
Triggering anti-cheats	Very likely	Mostly not

Disclaimer

It cannot be guaranteed that this mod is allowed on specific servers as it can possibly cause problems with anti-cheat plugins.
(USE ONLY WITH CAUTION!)