NinE X

Posted on Jun 27 • Originally published at github.com

I open-sourced A full-stack, peer-to-peer coinflip betting game on Solana

#solana #web3 #typescript #anchor

A full-stack, peer-to-peer coinflip betting game on Solana

A full-stack, peer-to-peer coinflip betting game on Solana. Players connect a wallet, create or join on-chain game rooms, 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 backend tracks rooms, chat, and match history in MongoDB.

I open-sourced coinflip-casino for developers in Solana / Anchor smart contract development. This post walks through what it does, how the pieces fit together, and how to run it locally.

Live demo / site: https://www.flip.is/

Why I built this

Learn full-stack Web3 game architecture (wallet + program + backend + UI)
Study provably fair randomness with on-chain VRF integration
Fork and customize a peer-to-peer on-chain betting room model

Most tutorials stop at a smart contract or a UI mockup. I wanted a complete vertical slice — wallet flow, on-chain logic, backend state, and a responsive frontend — so you can study or fork a production-shaped codebase.

What it does

Create a room — Pick Head or Tail, set bet amount, choose SOL or SPL token.
Join a room — Browse open games in the live lobby and match against another player.
PvP coinflip — When two players are in the same room, the backend triggers on-chain resolution.
2× payout — The winner receives double the bet (fees apply on-chain).
Room expiration — Open rooms older than 5 minutes with no opponent are expired and refunded automatically.
Portfolio stats — Win count and total games per wallet.
Wallet connect — players sign in with a Solana wallet
Peer-to-peer rooms — create or join head-to-head matches

Architecture at a glance

Wallet layer — users connect a Web3 wallet to sign transactions
On-chain program — Anchor/Rust logic for escrow, rooms, and settlement
Randomness — verifiable flip outcomes via Orao VRF on Solana
Real-time layer — WebSocket events push room and flip state to the UI
Persistence — MongoDB stores rooms, chat, and historical match data
Application layer — TypeScript backend/frontend tying on-chain and off-chain flows

User Wallet  →  On-chain Program  →  VRF / Settlement
                    ↓
              Backend (API + WebSockets)  →  MongoDB / state
                    ↓
                 Frontend UI (real-time)

Adjust the diagram to match your repo layout if components differ.

Tech stack

Solana
Anchor
TypeScript
MongoDB
WebSockets
Orao VRF
React

Quick start

git clone https://github.com/xxniiinxx/coinflip-casino.git
cd coinflip-casino

Setup steps:

Install dependencies (see README — typically npm install or yarn)
Copy .env.example to .env and fill in RPC, wallet, and API keys
Run local validator or point to devnet/mainnet as documented
Start the backend and frontend; connect wallet and create a test room

See the full README for environment variables, deploy scripts, and test commands: https://github.com/xxniiinxx/coinflip-casino

Video walkthrough

Coinflip Casino on Solana tutorial — How to set up and run coinflip-casino step by step
Coinflip Casino on Solana — Coinflip Casino on Solana — architecture and demo walkthrough

What to explore in the repo

Program / contract entrypoints and account models
API routes and WebSocket event handlers
Frontend wallet adapter and game room components
Tests, scripts, and deployment configs

Contributing

Issues and PRs are welcome. If this helped you learn something, a ⭐ on GitHub makes it easier for others to find.

anchor #betting #blockchaingame #casino #coinflip #cryptocurrency

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