Decentralized Rotating Savings and Credit Association (ROSCA) on Aptos

ChitChain modernizes the centuries-old chit fund model by deploying it on the Aptos blockchain. Using the safety guarantees of Move and the parallel execution of Block-STM, ChitChain eliminates intermediary risk while enabling instant dividend distribution.

• Trustless Operation: Smart contracts replace the traditional "Foreman", eliminating fraud risk
• Instant Dividends: Auction discounts distributed immediately using Aptos parallel execution
• Low Fees: <1% protocol fee vs 5-7% traditional chit fund fees
• Zero Default Risk: Phase I collection ensures full collateralization
• Market-Driven: Bidding mechanism discovers true cost of capital

1. Creator sets up a pool with contribution amount and member limit
2. Members join and deposit their full contribution as collateral
3. Once the pool is full, collection phase begins

1. Monthly auctions where members bid for the pot
2. Highest bidder (offering largest discount) wins
3. Winner receives: Pot - Discount
4. Other members receive: Discount / (N-1) as immediate dividend
5. Repeat until all members have won

chitchain/
├── contracts/               # Move smart contracts
│   ├── sources/
│   │   ├── pool.move       # Pool creation & management
│   │   ├── auction.move    # Bidding & auction logic
│   │   ├── treasury.move   # Fund distribution & escrow
│   │   ├── events.move     # Event definitions
│   │   └── errors.move     # Error codes
│   └── tests/              # Move unit tests
│
├── frontend/               # Next.js web application
│   ├── src/
│   │   ├── app/           # Next.js App Router pages
│   │   ├── components/    # React components
│   │   ├── hooks/         # Custom React hooks
│   │   ├── lib/           # Utilities & Aptos client
│   │   └── providers/     # Context providers
│   └── public/
│
└── scripts/                # Deployment scripts

• Node.js v18+
• Aptos CLI
• Petra Wallet or compatible Aptos wallet

git clone https://github.com/yourusername/chitchain.git
cd chitchain

cd contracts

# Initialize Aptos (creates .aptos/config.yaml)
aptos init --network testnet

# Compile contracts
aptos move compile --named-addresses chitchain=default

# Run tests
aptos move test --named-addresses chitchain=default

# Deploy to testnet
aptos move publish --named-addresses chitchain=default --assume-yes

Save the deployed module address for the frontend configuration.

cd ../frontend

# Install dependencies
npm install

# Configure environment
cp .env.example .env.local
# Edit .env.local with your module address:
# NEXT_PUBLIC_MODULE_ADDRESS=0x<your_deployed_address>
# NEXT_PUBLIC_NETWORK=testnet
# NEXT_PUBLIC_APTOS_API_KEY=your_api_key_here (optional, get from https://geomi.dev)
# NEXT_PUBLIC_APTOS_RPC_URL=https://api.testnet.aptoslabs.com/v1 (optional, custom RPC endpoint)

# Start development server
npm run dev

Open http://localhost:3000 in your browser.

If you and a friend are on different networks and can't see each other's pools, verify both are using the same configuration:

1. Check the Configuration Diagnostics card on the pools page - it shows:

   • Network (Configured): The network from your .env.local file
   • Detected from RPC: The network detected from the RPC endpoint URL
   • RPC Endpoint: The actual endpoint being used
   • Module Address: Must match on both devices

2. Ensure both have the same .env.local file:

   NEXT_PUBLIC_NETWORK=testnet
   NEXT_PUBLIC_MODULE_ADDRESS=c1c71853104465563071e7c615bd4c0fe1cab1a929281588dde3aeda61744163
   NEXT_PUBLIC_APTOS_RPC_URL=https://api.testnet.aptoslabs.com/v1

3. If you see "Network Mismatch" warning: Your configured network doesn't match the RPC endpoint. Update NEXT_PUBLIC_NETWORK to match.

4. Restart the dev server after changing environment variables:

   # Stop the server (Ctrl+C) and restart
   npm run dev

• Move Safety: Linear type system prevents asset duplication
• Formal Verification: Critical functions verified with Move Prover
• Collateralization: Phase I deposits eliminate default risk
• Griefing Protection: Failed transfers escrowed for manual claim

• Core smart contracts (Pool, Auction, Treasury)
• Web frontend with wallet integration
• Telegram bot for notifications
• Move Prover specifications
• Mainnet deployment
• Thala yield integration for Phase I deposits
• Cross-chain support via LayerZero

Contributions are welcome! Please read our contributing guidelines before submitting PRs.

MIT License - see LICENSE for details.

• Aptos Documentation
• Move Language
• Aptos Explorer

Built with ❤️ for the Aptos Code Collision Hackathon