qmux 0.5.0

QMux protocol (draft-ietf-quic-qmux-02) over reliable transports
Documentation

qmux

A Rust implementation of the QMux protocol (draft-ietf-quic-qmux-02, negotiating down to draft-01 and draft-00).

QMux brings QUIC's multiplexed streams and flow control to reliable, ordered byte-stream transports like TCP and WebSockets. It allows applications built for QUIC to seamlessly fall back to TCP/TLS when UDP is blocked by network middleboxes, without maintaining separate protocol implementations.

The protocol reuses QUIC frame types and semantics while adapting them for stream-based transports, providing multiplexed streams with flow control and optional unreliable datagrams.

Install

[dependencies]
qmux = "0.4"

Features

  • tcp - QMux over raw TCP streams
  • uds - QMux over Unix domain sockets (Unix only)
  • tls - QMux over TLS (via tokio-rustls)
  • ws - QMux over WebSockets (via tokio-tungstenite)
  • wss - QMux over secure WebSockets (WebSocket + TLS)

Default features: tls, wss

Usage

The crate root holds the transport-independent session API — Session, SendStream, RecvStream, Config, Version, and Error. Each transport keeps its own entry point in its own module, so the shared names don't collide:

Module Entry point Feature
qmux::tcp tcp::Config tcp
qmux::uds uds::Config uds
qmux::tls tls::Client, tls::Server tls
qmux::ws ws::Client, ws::Server, ws::Upgraded ws
qmux::transport transport::Stream tcp or uds 
use qmux::{tcp, Error, Session, Version};

async fn connect(addr: std::net::SocketAddr) -> Result<Session, Error> {
    tcp::Config::new(Version::QMux02)
        .protocols(["moq-lite-04"])
        .connect(addr)
        .await
}

To run QMux over something the built-in modules don't cover, wrap any AsyncRead + AsyncWrite byte stream in transport::Stream, or implement transport::Transport yourself, then pass it to Session::connect / Session::accept.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.