@agent-wasm/core

Node.js in your browser. Just like that.

The core runtime behind agent-wasm: a browser-native Node.js environment with an in-memory filesystem, a real npm package manager (downloaded + ESM→CJS transformed via esbuild-wasm), HTTP servers intercepted through a service worker, and dev servers for Vite and Next.js.

npm install @agent-wasm/core

import { createContainer } from "@agent-wasm/core";

const container = createContainer();
container.vfs.writeFileSync("/index.js", "console.log('hello from the browser')");
await container.run("node index.js");

What's in the box

• VirtualFS — in-memory filesystem, exposed to code as require('fs').
• Runtime / createRuntime / WorkerRuntime / SandboxRuntime — the JS execution engine with require(), ESM→CJS transforms, and 43 built-in module shims (fs, path, http, net, stream, crypto, child_process, …).
• PackageManager — installs real npm packages, served via /_npm/.
• ViteDevServer / NextDevServer — React + HMR, Next Pages + App Router.
• electron shim + setElectronHost / launchElectronApp — emulate the Electron main process (app, BrowserWindow, ipcMain) and run modern (contextIsolation + preload) Electron apps from source; each BrowserWindow renders as a host-supplied iframe with postMessage IPC. See examples/electron-demo.*.
• createContainer / ContainerInstance — orchestration: vfs, workspace, git, terminal sessions.
• ServerBridge — service-worker network interception for in-VFS servers.
• network — Tailscale-backed networking namespace.

Subpaths

| Import | Purpose | | --- | --- | | @agent-wasm/core | the runtime API above | | @agent-wasm/core/internal | internal helpers (OXC linter, Fly/Infisical, auth shims) | | @agent-wasm/core/vite | almostnodePlugin() — serve the service worker in dev | | @agent-wasm/core/next | getServiceWorkerContent() / getServiceWorkerPath() |

License

MIT