A provably fair crash game built on Yellow Network's state channels for instant, gasless multiplayer gameplay with cryptographic security.
Higher!! is a multiplayer crash game where players predict a multiplier (1.01x-10.00x) before the rocket crashes. The game leverages Yellow Network's off-chain state channels for real-time, gas-free gameplay while maintaining the security and finality of on-chain settlements on Base Sepolia testnet.
- Instant Gameplay: Off-chain state channels eliminate gas costs and confirmation delays
- Provably Fair: Deterministic crash outcomes verified through cryptographic signatures
- Multi-Player Support: Real-time synchronization via Yellow Network's WebSocket RPC
- Secure Settlements: Multi-signature state updates with atomic on-chain finalization
- Automated Flow: Auto-start sessions, auto-sign transactions, and auto-reset lobbies
Yellow Network provides state channel infrastructure for building scalable, low-latency trading and gaming applications. It enables off-chain state transitions with cryptographic guarantees, settling final results on-chain.
We integrate Yellow Network through the @erc7824/nitrolite SDK (v0.5.3), which provides:
- Session Management: Create multi-participant sessions with EIP-712 authorization
- Off-Chain State Updates: Apply state transitions (bets, outcomes) without blockchain transactions
- Withdrawal Primitives: Move funds between unified balance (off-chain) and on-chain wallets
import { Nitrolite, ParticipantAuthorization } from '@erc7824/nitrolite';
// Initialize Nitrolite client
const client = new Nitrolite({ transport: wsRpcUrl });
// Authenticate with Yellow Network
await client.authenticateParticipant({
challenge,
signature,
authToken
});Players authenticate using EIP-712 typed data signatures:
// Request authentication challenge from Yellow Network
const { challenge, authToken } = await client.requestParticipantAuthChallenge({
appName: 'crash-test-app',
scope: 'session-participant',
participant: walletAddress,
allowances: [{ asset: 'ytest.usd', amount: '1000000' }]
});
// Sign with session private key (client-side)
const signature = await account.signTypedData({
domain: { name: 'crash-test-app', version: '1' },
types: { /* EIP-712 types */ },
primaryType: 'ParticipantAuth',
message: challenge
});
// Complete authentication
await client.authenticateParticipant({ challenge, signature, authToken });Each game round is a Yellow Network session:
// Start a new session (server-side)
const session = await client.startSession({
sessionId: crypto.randomUUID(),
participants: [adminAddress, ...playerAddresses],
allowances: { 'ytest.usd': '1000000' }
});
// Authorize participant (client-side)
await client.authorizeParticipantSession({
sessionId,
participant: walletAddress,
signature: await wallet.signTypedData(authTypedData)
});Game logic (bets, payouts) is encoded as pending actions:
// Create start action (collects bets)
const startAction = await client.createPendingAction({
sessionId,
actionType: 'start',
balanceChanges: {
[player1]: { 'ytest.usd': '-100' }, // Bet amount
[player2]: { 'ytest.usd': '-200' }
}
});
// Players sign the action
await client.signPendingAction({
actionId: startAction.id,
signature
});
// Finalize when all signatures collected
await client.finalizePendingAction({ actionId: startAction.id });After the crash, payouts are calculated and applied:
// Create end action (distribute payouts)
const endAction = await client.createPendingAction({
sessionId,
actionType: 'end',
balanceChanges: {
[winner1]: { 'ytest.usd': '+150' }, // 1.5x payout
[winner2]: { 'ytest.usd': '+0' } // Lost bet
}
});
// Multi-sig signing by all participants
// Finalize to commit state changes
await client.finalizePendingAction({ actionId: endAction.id });
// End session (final on-chain settlement)
await client.endSession({ sessionId });Yellow Network supports two withdrawal paths:
A. Unified to On-Chain (via settlement contract)
const { tx } = await client.prepareWithdrawUnifiedToOnchainTransaction({
participant: walletAddress,
asset: 'ytest.usd',
amount: '500'
});
// Submit transaction on-chain
await wallet.sendTransaction(tx);B. Layer-2 to Hot Wallet (internal transfer)
await client.prepareWithdrawToWallet({
participant: walletAddress,
asset: 'ytest.usd',
amount: '500'
});
// Execute withdrawal
await client.executeWithdrawToWallet({ withdrawalId });- Node.js 18+ and npm
- MetaMask or compatible Web3 wallet
- Base Sepolia testnet ETH (for gas)
- yUSDC tokens (get from faucet)
# Clone the repository
git clone https://github.com/your-repo/higher.git
cd higher/frontend
# Install dependencies
npm installCreate a .env.local file:
# Admin wallet (server-side signing)
ADMIN_PRIVATE_KEY=0x...
# Yellow Network Configuration
YELLOW_WS_URL=wss://clearnet-sandbox.yellow.com/ws
YELLOW_APP_NAME=crash-test-app
YELLOW_ASSET_ID=ytest.usd
YELLOW_AUTH_ALLOWANCE=1000000
# Blockchain Configuration
NEXT_PUBLIC_BASE_CHAIN_ID=84532
NEXT_PUBLIC_TOKEN_SYMBOL=yUSDCnpm run devOpen http://localhost:3000 and navigate to /game.
npm run build
npm start- Connect Wallet: Click "Connect Wallet" and select your Web3 wallet
- Join Lobby: Click "Join Game" (approves yUSDC token and joins lobby)
- Place Bet: Enter a multiplier prediction (1.01x - 10.00x)
- Auto-Start: Game auto-starts when players join
- Auto-Sign: Your wallet auto-signs the session authorization
- Watch Crash: The multiplier rises until the rocket crashes
- Settlement: Winners are paid out automatically via Yellow Network
- Auto-Reset: Lobby resets after 5 seconds for the next round
- Auto-Start: Fires 10s after last player joins (see
tryAutoStartSessionin/api/game/join) - Auto-Sign: Client auto-signs pending actions when detected (see
useGameLoop.ts) - Auto-End: Server auto-ends session 6s after crash (see
page.tsx) - Auto-Reset: Client triggers reset 5s after game ends
Set to MIN_PLAYERS = 1 for solo testing. Change in src/server/game-store.ts:
const MIN_PLAYERS = 1; // Change to 2 for multiplayerBuilt with 💛 on Yellow Network