Block Party

A 3D brick-building sandbox that runs in your browser. Snap bricks onto a grid, stack them up, and build your World — on your own, or together with others in real time over the network.

Built with Three.js, Vite, and Socket.IO.

A LAN-party game (v1.0). Block Party is made for people on the same network (or the same room): play side-by-side on your LAN, or with remote friends over a private encrypted overlay like ZeroTier or Tailscale. It's intentionally lightweight — a username + PIN, plain HTTP — which is exactly right on a trusted network, and exactly why you should not put it on a public IP. Keep it on your LAN/VPN and you're all set.

Quick start — self-host on Ubuntu Server 24.04 LTS

On a fresh Ubuntu Server 24.04 LTS box, one command installs everything (Node.js, the app, a build) and starts it as a service on port 80:

curl -fsSL https://raw.githubusercontent.com/bufanoc/block-party/main/install.sh | sudo bash

Then open http://<your-server-ip>. Re-run the same command to update.

Want to see what it does first? Read install.sh — it's short. Prefer to do it by hand? See Run your own server below.

Features

• Click to place bricks, right-click to delete, with a live ghost preview
• Grid snapping and automatic stacking; many brick shapes + a classic palette
• Solo sandbox — offline, saved to your browser (no server needed)
• Play together — accounts, a lobby of shared Projects, and real-time co-building in the same World
• Project sizes & colors — pick a baseplate size (Small / Medium / Large) and color when you create a World
• Creator controls — each Project has an owner who can require approval to join, freeze the build, rename, clear, or delete it
• Rotate (R), Undo (Ctrl/Cmd+Z — solo), and Clear

Play

Playing needs nothing but a browser — open the URL your host gives you on any desktop or laptop (Windows, macOS, Linux). Solo sandbox works with no account; Play together asks for a name and a PIN.

Mobile (phones/tablets) is experimental in this release — the 3D builder may run, but the touch controls and on-screen panels aren't tuned for small screens yet. It's on the roadmap.

Develop

Two processes — the Vite dev server for the front-end, and the game server:

npm install
npm run dev      # front-end on http://localhost:5173
npm run server   # multiplayer game server on http://localhost:3001 (separate terminal)

Open http://localhost:5173. (Solo mode needs only npm run dev.)

Run your own server

Supported platform: Ubuntu Server 24.04 LTS. That's what Block Party is built and tested on. It will likely run on any 64-bit Linux with Node.js 18+, but Ubuntu 24.04 LTS is the only configuration guaranteed to work. The server needs Node.js 18 or newer.

1. Install Node.js and git

Ubuntu 24.04 ships a compatible Node.js (18.x):

sudo apt update
sudo apt install -y nodejs npm git

(Optional — for a current LTS via NodeSource instead:)

curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt install -y nodejs git

2. Get the code and build it

git clone https://github.com/bufanoc/block-party.git
cd block-party
npm ci
npm run build

3. Run it

In production the server serves the whole app and the multiplayer socket on a single port — and defaults to port 80 (clean URLs). Port 80 is privileged, so for a quick foreground run either use sudo, or pick an unprivileged port:

sudo npm start                 # port 80  → http://<server-ip>
# or, no sudo needed:
PORT=8080 npm start            # port 8080 → http://<server-ip>:8080

If you use the firewall, open the port (80 or 8080):

sudo ufw allow 80/tcp

For anything long-lived, use the systemd service below — it binds port 80 without running as root.

Keep it running (systemd) — recommended

So it starts on boot, restarts on failure, and binds port 80 as an unprivileged user. Create /etc/systemd/system/block-party.service (replace the path and user):

[Unit]
Description=Block Party server
After=network.target

[Service]
WorkingDirectory=/home/USER/block-party
ExecStart=/usr/bin/node server/index.js
Environment=PORT=80
Environment=NODE_ENV=production
Restart=on-failure
User=USER
# Lets the unprivileged user bind port 80 (no running as root).
AmbientCapabilities=CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target

Then enable and start it:

sudo systemctl daemon-reload
sudo systemctl enable --now block-party
sudo systemctl status block-party

Updating to a newer version

cd block-party
git pull
npm ci
npm run build
sudo systemctl restart block-party   # or restart your `npm start` process

Data and backups

Accounts and Worlds are stored as plain JSON under data/ (git-ignored). Back up that folder to preserve everyone's builds.

Changing the port

PORT=3000 node server/index.js

(or edit the Environment=PORT= line in the service file).

Security & networking

Block Party is designed to live on a trusted network, and its security model assumes exactly that:

• On your LAN — just share the URL with people on the same Wi-Fi/network.
• With remote friends — put everyone on a private encrypted overlay like ZeroTier or Tailscale, then share the server's overlay address. Your traffic rides inside their end-to-end encryption, and only invited members can reach it.
• Do not expose it directly on a public IP. Auth is a lightweight username + PIN (hashed with scrypt), traffic is plain HTTP, and there's no rate-limiting or quotas — all fine among people you've invited to a private network, not fine facing the open internet.

If you ever do want a public, hardened deployment, that's a future step (reverse proxy + HTTPS + rate-limiting) — but it's deliberately out of scope for this LAN-party release.

Controls

Action	Input
Place brick	Left click
Delete brick	Right click
Orbit camera	Left drag
Zoom	Scroll
Rotate piece	R
Undo (solo)	Ctrl+Z / Cmd+Z

License

Released under the Block Party License (BSD 3-Clause with an attribution requirement) — see LICENSE.

You are free to use, modify, and redistribute this software, in whole or in part, provided you give clear, visible credit to the original author:

Based on Block Party by Carmine Bufano https://carminebufano.com https://github.com/bufanoc/block-party

Disclaimer

LEGO® is a trademark of the LEGO Group, which does not sponsor, authorize, or endorse this project. Block Party is an independent, fan-made building sandbox and is not affiliated with the LEGO Group.