deckcraft/packaging/web

Hosting SlideCraft for the web

slidecraft-web-<version>.zip (from the GitHub release, or packaging/web/package.sh) holds a static site in slidecraft-web-<version>/:

File	What it is
index.html	The page. It loads everything through relative URLs.
slidecraft-web-<hash>.js	wasm-bindgen glue (generated, ES module)
slidecraft-web-<hash>_bg.wasm	The app, size is printed by packaging/web/package.sh
_headers, .htaccess	Sample header rules for Netlify/Cloudflare Pages and Apache

There is no server-side code. Upload the folder's contents anywhere that serves static files.

Any path works

All URLs in index.html are relative (public_url = "./" in apps/slidecraft-web/Trunk.toml), so the site works at a domain root (https://example.com/), under a prefix (https://example.com/tools/slidecraft/) and from a CDN bucket. The asset names carry a content hash, so they can be cached forever. Only index.html needs revalidation.

Required server settings

• MIME type: serve .wasm as application/wasm. Browsers refuse to stream-compile it under any other type, and the app then loads slowly or not at all. Serve .js as text/javascript. Most hosts already do both. For nginx, check that mime.types has application/wasm wasm;.
• Compression: turn on gzip or Brotli for .wasm, .js and .html. That shrinks the download by roughly 60%. You can also precompress (brotli -k *.wasm) and let the server send Content-Encoding: br.
• Caching: Cache-Control: public, max-age=31536000, immutable on the hashed .wasm and .js files, and no-cache on index.html.
• HTTPS: WebGPU (and the clipboard) only work in a secure context, which means https:// or http://localhost. Over plain HTTP elsewhere, the app falls back to WebGL2.
• No special isolation headers: SlideCraft doesn't use SharedArrayBuffer, so it doesn't need Cross-Origin-Opener-Policy or Cross-Origin-Embedder-Policy. If your site already sends COEP require-corp, also send Cross-Origin-Resource-Policy: same-origin (or cross-origin when the files live on a CDN) on the app's files.

nginx example:

location /slidecraft/ {
    types { application/wasm wasm; text/javascript js; text/html html; }
    gzip on;
    gzip_types application/wasm text/javascript text/html;
    location ~* \.(wasm|js)$ { add_header Cache-Control "public, max-age=31536000, immutable"; }
    location ~* index\.html$ { add_header Cache-Control "no-cache"; }
}

Local test: python3 -m http.server 8765 inside the folder, then open http://localhost:8765/.

Embedding in a page (iframe)

<iframe
  src="https://example.com/slidecraft/"
  title="SlideCraft presentations"
  style="width: 100%; height: 720px; border: 0;"
  allow="fullscreen; clipboard-read; clipboard-write"
  allowfullscreen>
</iframe>

• The app fills the iframe and follows its size, so size the iframe and not the app.
• Keyboard shortcuts go to the iframe after the user clicks into it, as with any embedded app.
• Cross-origin embeds work. The web build keeps no preferences between visits; it starts with the sample deck (or ?blank) every time.
• Sandboxed iframes need at least sandbox="allow-scripts allow-same-origin allow-downloads allow-popups". Without allow-downloads, Save and Export (browser downloads) are blocked.
• Don't send X-Frame-Options: DENY or a frame-ancestors CSP that excludes the embedding page.

Renderer selection and fallback flags

SlideCraft renders with wgpu. It uses WebGPU when the browser has it and falls back to WebGL2 on its own. URL query flags override this, and they work on the iframe src too:

Flag	Effect
(none)	WebGPU if available, otherwise WebGL2
?webgl	Force the WebGL2 backend (useful when a WebGPU driver misbehaves)
?blank	Start with an empty presentation instead of the sample deck
?show	Start the slide show immediately (kiosk/embedded decks)

For example: <iframe src="https://example.com/slidecraft/?webgl" ...>.

A browser with neither WebGPU nor WebGL2 gets a message in place of the app.