muxws

HTTP/3 stream semantics over a WebSocket. Many independent, cancellable, bidirectional streams on one socket, either end able to open one - the model HTTP/2 and HTTP/3 already settled, without needing QUIC or an HTTP/3 stack. The wire format is the product; Python and TypeScript are the two ports that exist today, and SPEC.md plus conformance/ are what a third is written from.

The mimicry is of semantics, not transport: one TCP connection means one global message order and no per-stream loss recovery - the rationale says what is and is not copied. muxws is not a router, not a serializer of domain objects, not an authentication mechanism, not a durable store and not an RPC framework.

Install

pip install muxws                       # extras: [starlette], [websockets], [msgpack]
npm install muxws                       # optional peers: ws, @msgpack/msgpack

Documentation

docs.velis.si/muxws is the manual - or build it yourself with npm run docs:dev.

Status

0.1.0, alpha - the first release. Two versions that move independently: the wire is already at its first generation and frozen there (muxws.v1.<codec> is the subprotocol, and v1 stays until a breaking change earns a new one), while the package carries a leading zero because none of this has been through a real deployment yet. 1.0 is what the first confirmed production use earns. Python package muxws (PyPI); npm package muxws, browser entry plus the muxws/node and muxws/msgpack subpaths.

Licence

MIT. Copyright © 2025 Jure Erznožnik.