libxumux

TypeScript implementation of the xumux transport-agnostic channel multiplexing protocol.

Status: In development — implementing xumux v0.2.0-draft

What is xumux?

xumux lets you run multiple independent typed channels over a single connection — WebSocket, WebRTC DataChannel, TCP, stdio, or QUIC — with a standard binary framing format and handshake.

Install

npm install libxumux

Quick start

import { XumuxClient } from 'libxumux';
import { WebSocketAdapter } from 'libxumux/transports/websocket';

// Connect as client over WebSocket
const transport = new WebSocketAdapter('wss://example.com/xumux');
const client = new XumuxClient(transport);

// Open a named channel
const channel = await client.openChannel('my-channel');

// Write data
const writer = channel.writable.getWriter();
await writer.write(new TextEncoder().encode('hello'));

// Read data
const reader = channel.readable.getReader();
const { value } = await reader.read();
console.log(new TextDecoder().decode(value));

Transport adapters

Each transport is a separate entry point — import only what you use:

// Browser + Node.js
import { WebSocketAdapter } from 'libxumux/transports/websocket';
import { WebRTCAdapter }   from 'libxumux/transports/webrtc';
import { QuicAdapter }     from 'libxumux/transports/quic';

// Node.js only
import { TcpAdapter }   from 'libxumux/transports/tcp';
import { StdioAdapter } from 'libxumux/transports/stdio';

Development

task build          # Build ESM + CJS + .d.ts
task test           # Run tests
task test:coverage  # Run tests + coverage (≥85% required)
task check          # lint + typecheck + coverage (pre-commit gate)
task fmt            # Format with Prettier
task clean          # Remove dist/ and coverage/

Protocol

libxumux implements xumux v0.2.0-draft:

• 8-byte fixed binary frame header: [Channel:2][Type:1][Flags:1][Length:4]
• 2-byte channel IDs (up to 65,534 application channels)
• 4-byte payload length (up to ~4GB per frame)
• Fragmentation / reassembly for HOL blocking prevention and transport MTU compliance
• Control channel (0x0000) with HELLO/WELCOME handshake, keepalive, graceful close
• Dynamic channel lifecycle (OPEN_CHANNEL / CHANNEL_ACK / CLOSE_CHANNEL)

License

MIT