sk3chy

A peer-to-peer multiplayer drawing game with WebRTC for real-time gameplay and blockchain integration. Players compete to guess what the host is drawing, with cryptographic commitments ensuring fair play. Features BIP-39 word lists and optional on-chain game recording.

Tech Stack

• Nuxt 3 + Vue 3 — Game UI with Composition API and Nuxt UI
• Yjs — CRDT for real-time collaborative state (game state, drawing strokes, presence)
• WebRTC — Peer-to-peer connections for low-latency gameplay
• Statement Store — Substrate People chain for decentralized WebRTC signaling (no server needed)
• Polkadot Asset Hub — On-chain NFT minting and game recording
• Canvas API — HTML5 canvas for drawing and rendering

Game Mechanics

• BIP-39 Word Lists — ~800+ drawable words organized by difficulty
• Cryptographic Commitments — keccak256 hash with random salt prevents cheating
• 8-Player Limit with Spectator Mode
• Word Length Hints — Players see underlines representing letter count
• Timer System — Configurable game duration (30s to 5min)
• PNG Export — Canvas snapshots with game metadata

Getting Started

Install Dependencies

bun install

Development

bun dev

The game app will be available at http://localhost:3000.

Environment

Copy .env.example to .env and configure:

• NUXT_PUBLIC_STATEMENT_STORE_WS — Statement store WebSocket endpoint (default: PreviewNet)
• NUXT_PUBLIC_STATEMENT_STORE_SIGNING — Signing mode (mnemonic, ephemeral, or wallet)
• NUXT_PUBLIC_TURN_USERNAME / NUXT_PUBLIC_TURN_CREDENTIAL — Optional TURN relay credentials

Game Pages

• /play/[id] — Main game (statement store signaling, on-chain registration)
• /game-subs/[id] — Hybrid substrate game (statement store, ephemeral signing)
• /test-ss-signaling — Statement store connection test page

Testing

bun test

Runs Playwright E2E tests. The focused CRDT fallback smoke uses a local mock Statement Store so it is deterministic:

bun run test:crdt

To run the same CRDT fallback flow against a real Statement Store, provide a WebSocket endpoint and a test mnemonic that already has Statement Store allowance on that chain:

LIVE_STATEMENT_STORE_WS=wss://previewnet.substrate.dev/people \
LIVE_STATEMENT_STORE_MNEMONIC="..." \
bun run test:crdt:live

The live test writes statements under a unique sk3chy:crdt:* room topic, so use only disposable test credentials.

Manual testing:

1. Open http://localhost:3000/play/test1 in two browser tabs
2. Complete on-chain username registration if prompted
3. Both tabs should discover each other via statement store signaling

Production

bun build

Deploy to any Nuxt-compatible hosting platform (Vercel, Netlify, etc.)

Polkadot Host Product Build

Build the SPA as a host-compatible product archive:

APP_DOTNS_DOMAIN=sk3chy.dot bun run build:product

This writes dist/ with relative Nuxt assets and a manifest.toml.

The product runtime defaults to Paseo Next v2 Asset Hub:

wss://paseo-asset-hub-next-rpc.polkadot.io
0xbf0488dbe9daa1de1c08c5f743e26fdc2a4ecd74cf87dd1b4b1eeb99ae4ef19f

Deploy to Bulletin/DotNS with bulletin-deploy. The deploy script defaults to BULLETIN_ENV=paseo-next-v2:

APP_DOTNS_DOMAIN=sk3chy.dot bun run deploy:product

Set PUBLISH=1 to ask bulletin-deploy to publish the product manifest where supported. Secrets such as mnemonics should be provided only through the deploy CLI prompt or environment expected by bulletin-deploy; do not commit them.