A full-stack, peer-to-peer heads-or-tails betting arena on Solana — Players connect a wallet, open or accept on-chain matches, and compete head-to-head for 2× the stake. The UI updates in real time over WebSockets, outcomes are resolved on-chain with Orao VRF, and the server tracks matches, chat, and wallet stats in MongoDB.

FlipArena is split into three packages:

The production PvP program used by the client and server is deployed at:

472RXUv8zUX7zm4LprxNsFQvAZYEpSGaY9EUE4akCvG6

FlipArena/
├── fliparena-client/           # React + Tailwind + wallet adapter
│   ├── src/
│   │   ├── components/         # UI (arena, modals, header, chat)
│   │   ├── providers/          # Arena socket + effects providers
│   │   └── lib/                # RPC, program IDs, menu tokens
│   └── package.json
│
├── fliparena-server/           # WebSocket server + MongoDB
│   ├── services/               # Anchor txs, refunds, social notify
│   ├── models/                 # Match & chat schemas
│   ├── config/                 # DB connection
│   ├── constants/              # Program ID, seeds, token list
│   ├── index.ts                # WebSocket entry (port 8881)
│   └── package.json
│
├── fliparena-program/          # Anchor workspace (reference)
│   └── anchor-workspace/
│       ├── programs/coinflip/  # Rust program (unchanged on-chain name)
│       ├── tests/
│       └── cli/
│
└── readme.md

Create a MongoDB database (local or Atlas) and note credentials for .env.

cd fliparena-server
yarn install

Create fliparena-server/.env (see Configuration).

Place the program IDL at fliparena-server/program-idl.ts (gitignored). Copy from fliparena-program/anchor-workspace/target/types/coinflip.ts or your build artifacts.

yarn dev

WebSocket listens on port 8881.

cd fliparena-client
yarn install

Edit fliparena-client/src/lib/constant.ts:

• Set WS_HOST to ws://localhost:8881
• Set RPC to your Solana cluster URL

yarn start

Open http://localhost:3000.

Example:

RPC=https://api.devnet.solana.com
PRIVATE_KEY=your_base58_secret_key
FEE_RECEIVER=YourFeeReceiverPublicKey
DB_USERNAME=your_user
DB_PASSWORD=your_password
DB_HOST=cluster0.xxxxx.mongodb.net
DB_NAME=fliparena

fliparena-server imports the IDL from program-idl.ts. Regenerate after contract changes:

anchor idl parse -f target/idl/coinflip.json -o program-idl.ts

Connect to WS_HOST. Messages are JSON: { "type": "<EVENT>", ... }.

FlipArena keeps the existing deployed program unchanged:

• Program ID: 472RXUv8zUX7zm4LprxNsFQvAZYEpSGaY9EUE4akCvG6
• Instructions: createGame, joinOpposite, handleGame (called internally by server)
• PDA seeds: coinflip_global_main, coinflip_game
• Randomness: Orao Solana VRF

Only application-layer names (folders, models, WebSocket events, UI copy) were rebranded.

Default list in fliparena-server/constants/index.ts: SOL, USDT, USDC, BONK.

# Terminal 1 — server
cd fliparena-server && yarn && yarn dev

# Terminal 2 — client
cd fliparena-client && yarn && yarn start

Ensure MongoDB is running, .env is configured, program-idl.ts exists, and WS_HOST / RPC match your setup.

Keywords: FlipArena, Solana, anchor, PvP betting, blockchain-game, heads-or-tails, mongodb, websocket