A portfolio-grade financial infrastructure project implementing a Hybrid Clearing & Settlement Engine for Stablecoins.

It demonstrates how modern payment systems can combine the speed of off-chain ledgers (RTGS/Netting) with the trust and finality of on-chain settlement (Ethereum/ERC-20).

The Settlement Engine is deployed live on the Sepolia Testnet. You can verify the source code and view live settlement batches below:

The demo application (demo-app/) walks you through a complete financial lifecycle.

• Action: Go to Admin Panel -> Click "Inject 10 Transactions".
• Result: The system simulates 10 random inter-bank payments. These appear immediately in the Payment Ledger with status CLEARED.
• Concept: Simulates "RTGS" (Real-Time Gross Settlement) clearing on a private ledger.

• Action: Go to Admin Panel -> Click "Inject Circle Scenario".
  • System injects: A -> B ($100), B -> C ($100), C -> A ($100).
• Action: Go to Netting Cycles -> Click "Calculate Net Positions".
• Result: The engine analyzes the cycle, identifies the circular debt, and produces Zero Settlement Obligations.
• Concept: Demonstrates how Multilateral Netting can reduce liquidity requirements by 100%.

• Action: Connect your MetaMask (Sepolia) wallet.
• Action: In the Netting Cycles tab, click "Settle on Blockchain".
• Result:
  1. The app constructs a Batch Settlement Transaction.
  2. You sign it with MetaMask.
  3. The Smart Contract verifies the batch and moves funds between participants (if any obligations exist).
  4. The Payment Status updates to SETTLED (Finality).

1. Off-Chain Layer (Speed):
   • Clearing Engine: Validates ISO 20022 schemas, enforces compliance checks, handles high-throughput "messaging".
   • Netting Engine: Aggregates obligations to optimize capital efficiency.
2. On-Chain Layer await (Trust):
   • Settlement Contract: The "Source of Truth" for final funds movement. It only accepts signed batches from authorized operators.

• Frontend: React, TypeScript, Vite, Mantine UI.
• State Management: Zustand (Client-side localized database simulation).
• Web3: Wagmi, Viem, MetaMask SDK.
• Backend (Reference): Python, FastAPI, SQLAlchemy (in src/ folder - currently powering the logic ported to the frontend).
• Contracts: Solidity, Hardhat.

Run the visualization locally:

cd demo-app
npm install
npm run dev

Compile and deploy your own contracts (requires .env with SEPOLIA_RPC_URL and PRIVATE_KEY):

npm install
npx hardhat compile
npx hardhat run scripts/deploy.ts --network sepolia

• Flow Diagrams
• State Machine
• Netting Algorithm
• ISO 20022 Interoperability

This is a portfolio project/prototype. It is not audited for mainnet production use. The "USDC" used here is a mock testnet token.