KUBORA

◆ WHAT'S INSIDE ◆

Everything you need
to ship a world.

◨

Studio editor

A live 3D editor inspired by the best of the old web — drag parts, group them, tweak properties, and playtest in the same viewport.

{ }

JSON Game NEW

Author a full world as a JSON file — parts, scripts, spawn, settings. Drop it into Studio, play it live. Paste the docs into Claude and get a playable game back.

⟨⟩

Blocks or KUB

Write game logic with a visual block editor or switch to KUB text. Both modes talk to the same engine API — swap anytime, hot-reload always.

◉

Roblox import

Drop in .rbxl, .rbxlx, .rbxm, or .rbxmx files and KUBORA parses the tree into native parts.

▤

Scriptable UI NEW

Menus, HUD overlays and timers authored from a KUB script. Update a label every tick — the engine reconciles widgets by id, so nothing duplicates or flickers.

◈

Publish in one click

Hit Publish — your game lands in the Community shelf and anyone signed in can Play, instantly sharing a room with you.

◆ JSON GAME · NEW ◆

A world is
just a JSON file.

Every KUBORA world — parts, colors, scripts, spawn, settings — serializes into one clean JSON document. Write it by hand in VS Code, generate it with a script, or hand a prompt to Claude and let the model draft the whole world for you. Load it in Studio and the game runs.

One JSON button — dropdown: Import, Append, Export, Copy AI Prompt
Append mode — merge a prop pack / obstacle course into an existing world, no overwrite
Round-trip everything you built in Studio — parts, scripts, settings
Versioned — v: 2 today, forward-compatible
Prompt in the client — one click copies it to clipboard, no browser needed

Read JSON Game docs → Grab the AI prompt

hello.json JSON Game v2

1{
2  "v": 2, "name": "Neon Hop",
3  "start": [0, 4, 0],
4  "platforms": [
5    { "pos": [0,0,0], "size": [8,1,8], "color": "#7b61ff" },
6    { "pos": [6,2,0], "size": [3,1,3], "color": "#ff6ec7" },
7    { "pos": [12,4,0], "kind": "hazard" },
8    { "pos": [18,6,0], "kind": "finish" }
9  ],
10  "scripts": [
11    {
12      "name": "spinner", "lang": "kub",
13      "source": "every 1s do world.spin('p2', 30) end"
14    }
15  ]
16}

✦

Ship an AI-made game in one prompt

Copy a prompt from the docs. Paste into Claude. Get a world back.

The docs include a full system prompt that teaches the model the JSON Game schema, KUB language, and design rules. Ask for “a 20-platform lava parkour with a moving checkpoint” and Claude returns a ready-to-load .json.

Open the prompt →

◆ KUB LANGUAGE ◆

Write games
in KUB.

KUB is the scripting language baked into KUBORA. Reads like Lua, feels like a game language — events, parts, physics and multiplayer are built-in primitives, not libraries you pull off GitHub.

on for events — no callback spaghetti
part, player, world are first-class
Hot-reload — save, the running game updates live
Same API as the Blocks editor, switch freely

Read the KUB docs → Studio guide

lobby.kub KUB 0.1

1part spawn = world.find("SpawnPad")
2part portal = world.spawn("Portal", { color = "#b36eff" })
3
4-- every player who joins gets a welcome + teleport
5on player.join as p do
6  chat.say(p, "welcome to KUBORA, " .. p.name)
7  p:teleport(spawn.pos)
8  p.walk_speed = 18
9end
10
11-- touching the portal = random teleport across the map
12on portal.touch as p do
13  let target = world.random_point({ y = 4 })
14  p:teleport(target)
15  fx.burst(target, "sparkle")
16end
17
18every 5s do
19  portal:spin({ y = 180 }, 0.4)
20end

◆ NEW SCRIPTABLE UI ◆

Menus, HUD,
live timers.

From inside a KUB script you can author real menus, absolute-positioned HUD overlays, and timers that fire named functions. Update them every frame — the engine reconciles widgets by id, so calling menu_label(m, "score", str(n)) on every tick just updates that one row.

menu_* — windows with buttons, labels, sliders
hud_text / hud_bar — overlays in pixel coords
timer_every / timer_after — cancelable tickers
All widgets update in-place by id — no duplicates, no flicker

See the API → HUD reference

hud.kub KUB 0.2

1var score = 0
2var hp = 100
3
4-- Build a pause menu once; toggle it on Escape.
5let pause = menu_create("Pause")
6menu_button(pause, "resume", "Resume", "on_resume")
7menu_slider(pause, "vol", "Music", 0, 1, 0.7)
8menu_hide(pause)
9
10-- Tick every second — live HUD, no re-layout.
11timer_every(1, "on_tick")
12
13fn on_tick()
14  score = score + 1
15  hud_text("score", "Score: " + score, 20, 20, 0xffffff)
16  hud_bar("hp", hp, 100, 20, 48, 0x00d44a)
17end
18
19fn on_resume() menu_hide(pause) end

◆ BUILD ◆

A studio that feels
like a toy box.

Spawn primitives, paint them, stack them, wire them to a script. Live Mode runs your world with the same physics the shipped game uses — no "works in editor, breaks at runtime".

◨ Explorer tree with Models, Folders, and Parts
◨ Property panel: color, size, rotation, collidable, gravity
◨ Hazards, finish zones, moving platforms
◨ Autosave to cloud, or keep it local
◨ Project Settings with graphics quality + camera options

◆ MULTIPLAYER ◆

One shared room
per world.

Click Play, meet everyone else who clicked Play. No server picker, no shard list, no one spawning alone by accident. Real-time chat, inline invites, and live friend dots.

01

Invite in chat

Rich invite cards inline in DMs. Join or Decline with one click — the sender gets a courtesy reply either way.

02

Live presence

Green dots light up the moment a friend comes online. Positions update at 15 Hz over a Phoenix socket.

03

Fighting & parkour

Two built-in modes ship with the client. Your published games slot in alongside them.

◆ LIVE FROM THE CLOUD ◆

Games people are
building right now.

Every world marked public in Studio shows up here within a second — no refresh, no delay. This list is wired straight to the same Postgres your client reads from, over a live WebSocket. New game appears? It slides in.

— public games live

Connecting to cloud… Realtime via Supabase — updates appear without reloading.

◆ UNDER THE HOOD ◆

Built with stuff
that doesn't rot.

No Electron, no proprietary runtime, no dying framework. KUBORA is a native Rust binary that speaks to a Phoenix channel and a Postgres backend — a stack you can still run in ten years.

ENGINE

Rust + wgpu

Custom renderer, no Godot or Unity. Pure wgpu on top of winit, rapier for physics.

UI

egui

Immediate-mode UI that recompiles with the game — every panel is just a function.

SCRIPTING

Lua 5.4 + Blockly

Same engine API for both. Text people and visual people work in the same project.

NETWORK

Phoenix Channels

WebSocket realtime through Elixir. 15 Hz position sync, fanout chat, presence events.

BACKEND

Supabase

Postgres + auth + storage on the free tier. Every client is its own row-level-secure user.

IMPORT

RBX formats

Native parser for .rbxl, .rbxlx, .rbxm, .rbxmx. Drag in, play out.

◆ WHY KUBORA ◆

Made for players.
Not for shareholders.

KUBORA isn't a platform that will turn on its community in two years. Here's what you actually get when you install.

00

Free, always

No trial, no paywall, no premium tier. Every tool in the studio ships with the 21 MB executable.

01

Your game is yours

Save locally or to the cloud — your call. Export a project folder any time and walk away with the source.

02

No microtransactions

Zero in-game stores, zero gacha, zero cosmetics you rent for 90 days. The engine does not ship a currency.

03

Works offline

Build and test with no internet. Sign in only when you want to publish, chat, or hop into friends' lobbies.

04

Real language

KUB reads like a proper scripting language, not a stunted toy. Text people and visual people ship in the same project.

05

One runtime for all

What the editor plays is what a player plays. No "works in editor, breaks live" surprise at publish time.

◆ WE vs ROBLOX ◆

Same dream.
Different owners.

KUBORA is the game-making platform Roblox used to be before the shareholders showed up. Here's what that means in practice.

Roblox

The platform you grew up on

✕
Creators keep ~25¢ on the dollar. Robux cashout (DevEx) pays about $0.0035 per Robux, while players buy Robux at ~$0.0125 each. A 70% cut leaves the studio before taxes.
✕
Aggressive microtransactions everywhere. The default currency, the default monetization template, the default storefront — all built to pressure kids into buying Robux.
✕
Your game is hostage. No real export. You can't take your place off the platform — only Roblox's servers can run it, and only Roblox's client can play it.
✕
Moderation by algorithm. Hours of work can vanish to a false-positive ban with no human review and no real appeal path.
✕
Closed-source runtime. When Roblox breaks your game with a platform update, you wait. There's nothing to fork, no fallback.
✕
Ads & paid boosts to get seen. Discovery is now pay-to-play — sponsored tiles, paid impressions, algorithmic down-ranking if you don't monetize enough.
✕
One language, one IDE, one shop. Luau in Roblox Studio or nothing. No visual scripting for beginners, no real alternative for power users.
✕
You log in to them. Always-online. Servers down = you can't open the editor. No offline mode, ever.

The platform you deserve

✓
100% free, forever. No Robux, no tax on your game. The shop that ships with the client is cosmetics-only and its currency mints by itself while you play.
✓
No microtransactions by default. You can add a shop to your game if you want one, but the engine doesn't push one on your players.
✓
Your world is a file. One JSON. Save it locally, email it, put it on a USB stick. Anyone with KUBORA can run it — no account required.
✓
No silent bans. You can play offline. Even if we delete your cloud account tomorrow, the binary and your saves keep working on your disk.
✓
Open, readable runtime. Native Rust binary, ~22 MB. No Electron, no hidden telemetry, no 2 GB launcher that updates itself every week.
✓
Discovery by freshness, not ad budget. The Games tab is a live list of public worlds in recency order. You publish — you appear. That's it.
✓
Three authoring modes. Blocks for beginners, KUB for text people, JSON for AI. Same engine API behind all three.
✓
Works offline. Build, script, playtest — all without a network. Sign in only when you want to publish or hop into a friend's lobby.

Syncing live online counts… Updated every few seconds — refresh to force.

KUBORA LIVE

—

players online right now

Roblox APPROX

—

peak CCU, Roblox Q4 2025

KUBORA count is pulled live from our Supabase presence table. Roblox's public API blocks cross-origin reads, so we animate their last-reported peak CCU as a reference point — labeled APPROX so nobody gets misled.

◆ GET KUBORA ◆

Free forever.
No accounts sold.

Windows desktop alpha. macOS and Linux builds are on the roadmap.

◨Studio editor
⟨⟩KUB language
▥Blocks editor
{ }JSON Game (new)
◉RBX import
☍Multiplayer client

Windows x86_64 · v0.2

~22 MB Download .exe →

macOS Apple Silicon

Coming soon

Linux x86_64