QUIC Relay

A QUIC reverse proxy with SNI-based routing and optional TLS termination for protocol inspection and manipulation. Built for Hytale servers, works with any QUIC-based protocol.

What it does

Routes connections to backends based on domain (SNI). Optionally terminates TLS for protocol inspection and manipulation. Multiple servers can share a single IP and port.

┌──────────────┐                        ┌─────────────────────┐
│   Client A   │──play.example.com────▶│                     │──▶ Backend 1
├──────────────┤                        │     QUIC Relay      │
│   Client B   │──lobby.example.com───▶│     (port 5520)     │──▶ Backend 2
├──────────────┤                        │                     │
│   Client C   │──other.example.com───▶│                     │──▶ Backend 3
└──────────────┘                        └─────────────────────┘

Why this exists

Hytale uses QUIC on UDP port 5520. Unlike TCP-based games, there's no established method (like SRV records for Minecraft) to redirect players to different ports. Running multiple servers on one IP currently requires either:

• Different ports per server (inconvenient for players)
• A reverse proxy that routes based on SNI (this project)

Architecture

The proxy uses a handler chain. Each handler processes connections sequentially and decides whether to:

• Continue — pass to the next handler
• Handled — stop processing, connection was handled
• Drop — terminate the connection

This design allows combining handlers for different purposes: logging, rate limiting, routing, and forwarding.