Inspiration
Over 3 billion people worldwide participate in Rotating Savings and Credit Associations (ROSCAs) - known as Chama in Kenya, Susu in West Africa, Tandas in Mexico, and Hui in China. These informal savings circles have helped communities build wealth for centuries.
But there's a fundamental problem: trust. When someone takes the pot and disappears, everyone else loses their money. There's no recourse, no enforcement, no transparency. And with volatile currencies in many regions, savings can lose value overnight.
When we discovered MNEE - a USD-backed stablecoin on Ethereum - we saw the perfect opportunity. MNEE's stability means savings hold their value. Its programmability means we can automate enforcement. Its transparency means every transaction is auditable.
We asked: What if MNEE could power trustless savings circles? What if collateral was automatic, payouts were guaranteed in stable USD value, and reputation was on-chain?
What it does
ROSCA Protocol is a decentralized savings circle platform powered entirely by MNEE stablecoin where:
- Groups of 3-12 members contribute MNEE regularly to a shared pot
- Each round, one member receives the MNEE pot through an auction system
- Smart contracts enforce MNEE contributions, manage MNEE collateral, and distribute MNEE payouts
- On-chain reputation rewards reliable participants with lower collateral requirements (25% → 10%)
- AI features help users find matching circles, bid strategically, and assess risk
Why MNEE is Perfect for ROSCAs
| Traditional ROSCA Problem | How MNEE Solves It |
|---|---|
| Currency volatility destroys savings | MNEE is USD-backed - $100 today = $100 next month |
| No enforcement mechanism | Smart contracts automatically handle MNEE transfers |
| Trust required between members | MNEE collateral is locked programmatically |
| Opaque transactions | Every MNEE movement is on-chain and auditable |
| Geographic limitations | MNEE works globally, 24/7, no borders |
MNEE Flow in Our Protocol
┌─────────────────────────────────────────────────────────────┐
│ MNEE TOKEN FLOW │
├─────────────────────────────────────────────────────────────┤
│ │
│ JOIN CIRCLE │
│ └── Member deposits MNEE collateral (10-25%) │
│ │
│ EACH ROUND │
│ └── All members contribute MNEE to pot │
│ │
│ AUCTION │
│ └── Members bid MNEE amounts for payout priority │
│ │
│ SETTLEMENT │
│ └── Winner receives MNEE pot │
│ └── Surplus MNEE split among remaining members │
│ │
│ COMPLETION │
│ └── MNEE collateral returned to all members │
│ │
└─────────────────────────────────────────────────────────────┘
AI-Powered Features
| Feature | Description |
|---|---|
| Circle Finder | Natural language search to match users with MNEE savings circles based on goals |
| Bid Assistant | Analyzes on-chain MNEE data to recommend optimal bid amounts |
| Risk Scoring | Evaluates circle health and member MNEE payment history |
How we built it
Smart Contracts (Solidity 0.8.24)
All contracts integrate directly with the official MNEE token at 0x8ccedbAe4916b79da7F3F612EfB2EB93A2bFD6cF:
ROSCA.sol- Core logic: MNEE deposits, contributions, bidding, round settlementROSCAFactory.sol- Creates circles and configures MNEE as the payment tokenReputationRegistry.sol- On-chain credit scoring that determines MNEE collateral requirements
Key MNEE integration points:
IERC20 public immutable mneeToken; // Official MNEE contract
mneeToken.transferFrom(member, address(this), collateralAmount);
mneeToken.transfer(winner, potAmount);
Frontend (Next.js 16 + TypeScript)
- Built with React 19, Tailwind CSS v4, and wagmi v2
- Real-time MNEE balance displays and transaction tracking
- Responsive design optimized for both desktop and mobile
AI Integration (AWS Bedrock)
- Claude 3 Haiku powers all AI features
- Analyzes MNEE transaction history and on-chain state
- Provides MNEE-denominated recommendations
Demo Environment
- Anvil fork of Ethereum mainnet
- Uses the real MNEE contract - same address, same code, same behavior
- One-command setup:
bash demo.sh
Challenges we ran into
1. MNEE Decimal Precision MNEE uses 6 decimals (like USDC) instead of the typical 18. We had to carefully handle precision throughout the stack - from smart contract math to frontend displays - to ensure users always see accurate MNEE amounts.
2. MNEE Approval Flow Users must approve MNEE spending before joining circles or contributing. We implemented a smooth two-step flow: approve once, then interact freely. The UI clearly shows MNEE allowance status.
3. Auction Mechanics with MNEE Designing a fair auction where bids are in MNEE required careful thought. We settled on "lowest bid wins" - bidding 450 MNEE on a 500 MNEE pot means accepting less, incentivizing patience while giving urgent users early access to their MNEE.
4. Collateral Calculations Balancing security vs. accessibility with MNEE collateral. Too much MNEE locked up hurts capital efficiency; too little creates default risk. Our reputation-based tiers (25% → 10%) reward good MNEE payment history.
5. Real MNEE on Mainnet Fork Testing with the actual MNEE contract (not a mock) required forking mainnet. This added complexity but ensures our code works with the real token - no surprises at deployment.
Accomplishments that we're proud of
- 100% MNEE-powered - Every financial operation uses the official MNEE stablecoin, not mock tokens
- Full end-to-end flow - Users can create circles, deposit MNEE collateral, contribute, bid, and receive MNEE payouts
- Three AI features that analyze MNEE transaction data to improve user decisions
- One-command demo - Judges can spin up the entire system with
bash demo.shusing real MNEE - Programmable money in action - MNEE automatically moves based on smart contract rules: collateral locks, contributions collect, payouts distribute, surplus shares
- Clean, intuitive UI - Makes MNEE-based DeFi accessible to non-crypto users
What we learned
- MNEE enables programmable savings - The stability of USD backing plus Ethereum's programmability is incredibly powerful for financial applications
- Stablecoins unlock global finance - With MNEE, a savings circle can have members from Kenya, Mexico, and the Philippines - all saving in the same stable currency
- Traditional finance has wisdom - ROSCAs have worked for centuries. MNEE and smart contracts just remove the trust requirement.
- AI + on-chain MNEE data is powerful - Every MNEE transaction is immutable and auditable, providing perfect context for AI recommendations
- 6 decimals matter - MNEE's USDC-like precision required attention throughout the stack
What's next for ROSCA Protocol
- Yield on idle MNEE - Integrate with lending protocols so locked MNEE collateral earns interest
- MNEE gas sponsorship - Let users pay gas fees in MNEE for smoother onboarding
- Private circles - Invite-only MNEE savings groups with access codes
- AI agent participation - Autonomous agents that hold MNEE and participate in circles
- Cross-chain MNEE - Deploy wherever MNEE expands (L2s, other chains)
- Mobile app - React Native version for broader MNEE accessibility
- Fiat on/off ramps - Direct bank ↔ MNEE ↔ ROSCA flow for mainstream adoption
Built With
- ethereum
- foundry
- node.js
- solidity
- typescript
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