Web and Desktop Apps

Web and desktop apps

Your screens don't have to live in Minecraft. File → Export can also turn a project into a web page or a desktop program. They look and behave like the game: the same layout and anchors, conditions, actions, client scripts, Tick and Key events, animated textures and navigation between screens.

Format	You get	Runs on
Web page — folder	index.html, host.js, a wysicraft folder and your images	Any modern browser. Open index.html, or upload the folder to a website.
Web page — one HTML file	One .html file with everything inside, images included	Any modern browser. Easy to email or attach.
Windows app	A .zip with Name.exe, app.ini and an app folder	Windows 10 and 11. Unzip and run the .exe: nothing to install.
Electron apps	One download per platform you tick	Windows, macOS (Apple silicon and Intel) and Linux.

What's different outside Minecraft

The Export dialog lists anything in your project that won't work the same way:

• Minecraft textures and the Minecraft font belong to Mojang and can't be included. minecraft: textures show nothing, and text uses the system font. Import your own PNGs for backgrounds.
• Item icons show a placeholder, unless the project has an image for that item under textures/item. For example, assets/<namespace>/textures/item/diamond.png is used for minecraft:diamond.
• Server side: message, set_variable, toggle_variable, open_ui and close_ui work as usual, and server scripts run too. Things that need a Minecraft server go to host.js instead: command actions, ctx.server.runCommand, server_function and play_sound.
• KubeJS scripts don't run.
• Escape doesn't close the screen, unless you turn that on in host.js.

host.js: connect your own code

The folder export includes host.js. It's plain JavaScript that you edit, and re-exporting keeps your copy. Every hook is optional:

Hook	Called when
onCommand(command, info)	A Server command action runs, or a server script calls ctx.server.runCommand.
onServerFunction(name, value, info)	A server_function action runs.
onServerAction(action, info)	Any other Minecraft-only server action runs.
onSound(sound)	A play_sound action runs.
onMessage(text)	A message action or ctx.message runs. Return false to hide the built-in message line.
onClose(screen)	The screen is closed. Desktop apps close their window here.

info.app, which is also window.Wysicraft.app, lets your code change the UI, for example after fetching data:

onCommand(command, info) {
  if (command === 'refresh') fetch('/api/status').then(r => r.json()).then(s => info.app.setText('status', s.text));
}

app has open(screen), close(), setText(id, text), setValue(id, value), setVisible(id, bool), setEnabled(id, bool), getVariable(name), setVariable(name, value), message(text) and fire(elementId, eventName, value). host.js also sets closeOnEscape, guiScale (the size, like Minecraft's GUI scale), fontFamily, and the player details that server scripts see.

Windows app

The Windows app is a small program (under 1 MB) plus your web page. It shows the page in its own window using Microsoft Edge WebView2, which comes with Windows 10 and 11. It only ever shows your own files.

• Edit app.ini to change the window title and starting size.
• The .zip includes THIRD-PARTY-NOTICES.txt for the WebView2 loader inside the program. Keep it with the app if you share it.

Electron apps

Electron apps run on Windows, macOS and Linux, and are about 100 MB each.

• Download: the first time you export for a platform, Arcadia Studio downloads Electron's official build from its GitHub releases, checks it against Electron's published checksums, and keeps it in %LOCALAPPDATA%\Arcadia Studio\Electron for next time.
• You can build all three from Windows: Electron isn't compiled, so no Mac or Linux PC is needed.
• Windows is unticked by default: the Windows app format does the same job in under 1 MB instead of about 100 MB. Tick it only if you want your Windows build to match your Mac and Linux ones.
• macOS: the app isn't signed by Apple, so macOS says it's damaged when it's downloaded. Run xattr -cr "Your App.app" once in Terminal, or sign it on a Mac with your Apple developer account.
• Linux: extract the .tar.gz and run the program inside. If it complains about the sandbox, run it with --no-sandbox.

How big should a game be?

Every player downloads a web game over their own connection, so Arcadia Studio warns when one gets heavy. Nothing is refused; the warning just says what the wait will be.

Export	Warns past	Why
Web page (folder)	100 MB	Each player downloads it. At 10 Mbit/s, 100 MB is about a minute and a half.
Web page (one HTML file)	100 MB	The file carries everything as text, which makes it about a third bigger than the folder.
Windows app, Electron apps	500 MB	Downloaded once and kept. Electron adds about 100 MB to each app.

The Export dialog shows about how big the chosen format comes out, and the warning in yellow when it is over. The warning names the three biggest files. It stays in the log after the dialog closes, and Validate notes it too. Sounds are usually the biggest part: shorter or quieter songs, or lower Ogg quality, help most.

How files load in a web game:

• Pictures start loading as soon as the page opens.
• Sound effects are fetched and decoded when the page opens, so the first play of each is instant.
• Music played by a Sound control streams: it downloads while it plays, and it is not held in memory whole.
• A Play sound action or ctx.client.playSound on a long sound (over 512 KB) streams too, instead of being decoded whole.