windows-web-next

Project page: jacobfv.com/projects/windows-web-next · Used as a native execution substrate by SynthUX (github.com/JacobFV/synthux)

A browser-based Windows 11 simulation built in Svelte for human annotation and computer-use agent research.

What it is

• Recreates a desktop environment with window management, taskbar, start menu, and bundled apps in Svelte.
• Includes a reactive in-memory filesystem and app surface for realistic computer-use interaction traces.
• Serves as a controlled environment for annotation, evaluation, and agent training rather than a visual parody of Windows.

The repo is intentionally a research substrate: structured affordances (open app, navigate folders, manipulate files, resize windows, handle menus, move through a desktop workflow) are exposed so external agent/dataset systems can drive it without a real machine.

Local development

pnpm install
pnpm dev             # default port 5173
pnpm dev --port 5174 # alternate port for multi-sim runs

SynthUX bridge

src/lib/embed-bridge.ts exposes:

• window.__synthuxLaunchApp(appId) and a synthux-launch postMessage handler that route through wm.openApp(...). The SynthUX launcher overlay calls this on a real low-level click, so visible state changes still flow from real DOM events.
• A synthux.getState postMessage handler that returns the active workspace and window snapshot.

No other bridge command mutates state. See SynthUX for the executor side and the per-(env, surface) compilers that drive Notepad, Terminal, Edge, Mail, Wordpad, and VSCode here.