QUIC-MC

QUIC-MC

A mod and plugin that add QUIC (UDP) transport for Minecraft game traffic instead of the usual TCP connection.

Made up of two parts:

• Mod (Fabric, client) — installed by the player. Detects whether a server supports QUIC and transparently reroutes the game connection through a local tunnel. Browsing the server list never triggers any prompts — the trust dialog only appears when you actually try to join a server.
• Plugin (Velocity, server) — installed by the proxy server owner. Listens on a separate UDP port and accepts game connections through it from clients running the mod.

QUIC runs over UDP and, unlike TCP, doesn’t stall all data streams when a single packet is lost, and recovers connections faster. This can reduce latency and disconnects on unstable networks — provided both the server and the client are using QUIC-MC.

What to know before installing

• The mod only works with servers that have the QUIC-MC plugin installed. On regular servers it has no effect and traffic goes over TCP as usual.
• If you run a server, the plugin needs to be installed on the Velocity proxy — otherwise players with the mod won’t get any benefit.
• The server-side plugin currently only works on Linux x86_64. A Windows build isn’t ready yet (an upstream library issue), and macOS isn’t planned.
• Requires Java 21.

For players

1. Install the mod for your Minecraft version via Fabric Loader.
2. Join the server as usual. If the server supports QUIC, on first connection you’ll see a dialog with the address and a short identity code — compare it with the code published by the server owner, then enter the published access key once.
3. QUIC-enabled servers are marked with a ⚡ icon in the server list.

The access key and identity code are tied to that specific server and only requested once — after that, connecting happens automatically.

For server owners

1. Install the plugin on your Velocity proxy.
2. On first startup the plugin creates a config file and generates a unique access key for your server.
3. Open the required UDP port in your firewall and publish the access key and identity code somewhere players can see them (e.g. in your server description or website).

Platform support

| Platform | Mod (client) | Plugin (server) |
|—|—|—|
| Linux x86_64 | ✅ | ✅ |
| Windows x86_64 | ✅ | ⏳ pending (Windows native build isn’t ready upstream) |
| macOS | ⏳ planned | ❌ not planned |

Requirements

• Java 21
• Client: Fabric Loader
• Server: Velocity

Learn more

Technical documentation, architecture details, the security model, and build instructions are in the repository’s README on GitHub.

License

AGPL-3.0