smoltcpjs

A wasm-bindgen build of the smoltcp 0.13 IP stack, targeting WebAssembly. It exposes a Stack API over IPv6: raw L3 frame I/O, TCP, UDP, ICMPv6 echo, raw IPv6 sockets, and topic multicast (see COVERAGE.md for the full matrix).

Installers get prebuilt .js and .wasm; no Rust toolchain is required at runtime.

Use from npm

npm install smoltcpjs

import init, { Stack } from 'smoltcpjs'
await init() // or init({ module_or_path: new URL('smoltcpjs_bg.wasm', import.meta.url) }) in some bundlers
const stack = new Stack('2001:db8::1')
// … see COVERAGE.md and the published TypeScript types

• init() loads the WebAssembly (wasm-bindgen default). Your bundler may need an explicit module_or_path to the smoltcpjs_bg.wasm file next to the JS; check your bundler’s WASM docs.
• The package is ESM ("type": "module"). Use import, not require (or use createRequire in Node if you must).
• Invalid IPv6 in new Stack(…) throws; catch or validate the string first.

Developing this package

To change Rust code or wasm-pack output you need the Rust wasm target, wasm-pack, and dependencies as resolved by cargo (see Cargo.toml):

• rustup target add wasm32-unknown-unknown
• npm install (for wasm-pack as a dev dependency) or a global wasm-pack install

npm run build

The web build is written to pkg/. A Node-target build can be produced with npm run build:node (outputs to pkg-node/, not published in the main npm files set).

npm test

Rebuilds wasm and runs the tests in test/.

Release checklist (npm)

1. Bump version in package.json and Cargo.toml together.
2. npm test (rebuilds wasm and runs test/smoltcpjs.test.mjs).
3. Dry-run the published tarball: npm pack --dry-run and confirm pkg/*.wasm and pkg/*.js are listed.
4. npm login (once) then npm publish (use --access public only if the package name were scoped and needed).

prepack runs npm run build, so npm pack and npm publish both build wasm first even if pkg/ is not committed (it is usually gitignored).

License

0BSD (see the license field in package.json).