Web

The entire engine — QuickJS, the raym3 renderer, and the rlwg WebGPU raylib backend — compiles to a single WebAssembly module. Your app runs unchanged in the browser, painted onto a canvas with WebGPU (4× MSAA), falling back to a WebGL2 host build where WebGPU is unavailable.

Develop

npm run web    # rayact dev --web

Starts the dev server plus a COOP/COEP proxy (default port 8768) and opens the dev host. Edits hot-reload like every other platform.

Release build

npm run build:web    # rayact build --release --web

Output in dist/web/:

File	Purpose
rayact.html / index.html	Host page (release-sanitized: no dev bootstrap)
rayact.js + rayact.wasm	The engine
app.qjsbc (or app.js)	Your bundle, compiled to QuickJS bytecode
app-assets.json	Manifest of runtime files the host preloads into MEMFS
rayact-assets/…, assets/…	Staged CSS and bundled assets (worker .wasm, images)

The host fetches app-assets.json before boot and copies every listed file into the WASM filesystem, so importCSS(...), spawnWorker(...) and asset reads behave exactly as they do natively.

Serving — COOP/COEP required

WebGPU + SharedArrayBuffer require a cross-origin isolated page. Serve with:

Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp

rayact serve does this for you:

rayact serve dist/web --web-port 8771

For production, set the two headers in your web server/CDN config. Everything is static files — any host works once the headers are right.

Canvas sizing

The browser owns the canvas resolution: the page sets the backing store to CSS size × devicePixelRatio and the engine treats it as read-only, so zoom, resize and fractional-DPI displays stay crisp. Mouse-wheel events scroll ScrollViews natively.

WASM workers need the pthreads host

spawnWorker() with a .wasm worker runs the worker on a real thread, which on the web requires SharedArrayBuffer — a pthreads-enabled host build. The release attaches rayact-web-pthreads-<version>.tar.gz; point builds at it:

RAYACT_WEB_HOST_DIR=/path/to/pthreads-host npm run build:web

The default host stays non-pthreads (the dev module loader is incompatible with pthreads), so apps without WASM workers need nothing special. JS-side code and worker views work on both hosts; only spawning WASM/native workers needs the pthreads variant.

Limitations on web

• @rayact/mmkv / @rayact/secure-store native modules are stubbed to in-memory/localStorage-backed KV.
• File-system paths refer to the in-memory MEMFS staged from app-assets.json.