An operating system that boots in a Web Worker
A real kernel running real processes — where JS and WASM are the native executable format. POSIX-style coreutils and bash-like scripting. The executable format is a JS or WASM module, not a native binary; the "CPU" is the host's own JS/WASM engine.
import { boot } from "@opentf/workeros-web";
// Boot the Rust→WASM kernel inside a Web Worker.
const os = await boot();
// The VFS is real: write a file, then run a program.
await os.fs.write("/hello.txt", "from the WorkerOS VFS\\n");
// wsh: pipes, &&, redirects, glob — executed by the kernel.
await os.exec("cat /hello.txt | cat && ls /sbin", {
onStdout: (b) => screen.write(b),
});
// Processes are real — inspect the live table.
const procs = await os.ps();Requires a Rust toolchain with the wasm32-unknown-unknown target, wasm-pack,
and Node.js.
# Native kernel tests (pure logic — no browser needed)
cargo test --workspace --exclude workeros-web-wasm
# Node-ism grep gate (keeps the kernel Node-agnostic — INV-1)
./ci/grep-gate.sh
# Build the kernel wasm + host runtime, then serve with COOP/COEP
cd packages/workeros-web
npm install
npm run build:wasm # or build:wasm:dev
npm run serve # http://localhost:8080
# Headless browser tests (boot handshake + MVP acceptance)
npm testOpen a demo at
http://localhost:8080/examples/run-js/index.html (run a JS program) or
http://localhost:8080/examples/shell/index.html (the wsh terminal).
Cross-origin isolation (COOP: same-origin, COEP: require-corp) is required
for SharedArrayBuffer; the dev server sets these headers (ADR-010).
To debug a guest program (a hang, a bad fs access), enable the kernel tracer
(os.trace(...)) or drive real programs with the e2e harness — see
DEBUGGING.md.
Apache-2.0. See NOTICE for attribution details.