Backend Services

The backend handles game logic, authentication, and real-time events.

Technology Stack

Component	Technology
Runtime	Node.js
Framework	Express
Database	PostgreSQL
ORM	Prisma
Language	TypeScript

Core Services

Game Logic (/services)

Service	Purpose
startHand.ts	Initialize new poker hands
playerAction.ts	Process fold/call/raise/check/all-in
pokerHandEvaluation.ts	Determine winning hands
potSplitting.ts	Calculate side pots

Authentication

Service	Purpose
userAuth.ts	Wallet signature verification
twitter.ts	Twitter OAuth handling
Middleware	walletAuth.ts, twitterAuth.ts

Asset Management

Service	Purpose
escrowBalance.ts	Track player balances
withdrawalSigning.ts	Sign withdrawal authorizations
contractListener.ts	Listen for on-chain events

API Structure

Public Endpoints (No Auth)

• GET /pokerTables - List all tables
• GET /tablePlayers - List players at a table
• GET /watchCurrentHand - Current hand state (no hole cards)
• GET /leaderboard - Top players

Authenticated Endpoints

• POST /joinTable - Join a poker table
• POST /standUp - Leave a table
• POST /action - Make a poker action
• GET /currentHand - Current hand with hole cards
• POST /signEscrowWithdrawal - Request withdrawal signature

Real-time

• GET /api/tables/:tableId/events - SSE stream for table events

Database Schema

Key models:

PokerTable
├── Hand (1:many)
│   ├── HandPlayer (1:many)
│   ├── HandAction (1:many)
│   └── Pot (1:many)
└── TableSeatSession (1:many)

PlayerEscrowBalance
Event (audit log)
LeaderboardStats

Event Signing

All game events are signed using EIP-712:

1. Event payload is serialized to JSON
2. EIP-712 digest is computed
3. Server signs with TEE private key
4. Signature (r, s, v) is stored with event

This creates a verifiable audit trail of all game actions.

Background Jobs

Job	Interval	Purpose
Action Timeout Checker	1.5s	Auto-fold timed-out players
Hand Start Checker	1.5s	Start hands when ready
Contract Listener	Real-time	Process on-chain events