websock

A minimal WebSocket library for native and WebAssembly.

Workspace crates

• websock: top-level facade that selects native (websock-tungstenite) or browser (websock-wasm) transport.
• websock-proto: shared protocol types and error model.
• websock-tungstenite: native transport powered by tokio + tungstenite (optional TLS via rustls).
• websock-wasm: browser transport based on the WebSocket API.
• websock-mux: top-level facade for multiplexed streams over WebSocket.
• websock-mux-proto: frame and varint primitives for the multiplexing layer.
• websock-tungstenite-mux: native multiplexed transport.
• websock-wasm-mux: browser multiplexed transport.
• websock-wasm-demo: small browser demo application.

Quick start

[dependencies]
websock = "0.5"

API documentation is available on docs.rs.

If you need transport-specific features, depend on one of the transport crates directly.

Native

See examples.

WebAssembly

The websock-wasm-demo crate includes a small browser app that connects to an echo server.

Resource limits

WebSocket clients and servers use conservative message, frame, and write-buffer limits by default. Customize them with WebSocketLimits:

use websock::{ClientBuilder, WebSocketLimits};

let client = ClientBuilder::new()
    .with_limits(WebSocketLimits {
        max_message_size: 2 * 1024 * 1024,
        max_frame_size: 512 * 1024,
        max_write_buffer_size: 2 * 1024 * 1024,
    })
    .build();

The mux transports additionally expose Limits for stream counts, queue capacities, batching, and per-stream flow-control windows. Invalid or inconsistent limits return a protocol error rather than panicking.

The multiplexing wire format, stream lifecycle, flow control, compatibility policy, and error codes are specified in docs/mux-protocol.md.

Benchmarking

Criterion benchmarks are available for websock-mux-proto.

cargo bench -p websock-mux-proto