starc

Problem Statement

Starc Protocol is a merchant-first payment layer designed to unify fragmented stablecoin liquidity. While merchants want to accept any token (ARS, EURC, USDC), managing a multi-asset treasury is complex and inefficient. Starc solves this with a dual approach:Unification Layer: The Starc Router accepts any whitelisted stablecoin and atomically swaps it into a single liquid asset (USDC) before depositing it into a yield-generating vault. Merchants simply receive StarcShares, representing a unified claim on the treasury. Merchant Services: We built a comprehensive suite of treasury automation tools directly into the dashboard: Automated Payroll: One-click distribution of funds to employee wallets using Circle's programmable infrastructure. Auto-Sweep: Automatically moves excess float into the yield-bearing vault. Cross-Chain Bridge: Integrated Circle CCTP widget for seamless cross-chain liquidity management. AI Treasury Agent: A context-aware AI agent (Gemini) that can analyze open invoices and execute payments via natural language.

Solution

The core architecture relies on StarcRouter.sol and StarcVaultV2.sol (ERC4626) on the Arc Testnet to handle the atomic swap-and-deposit flow. The frontend is built with Next.js 16, React 19, and Tailwind CSS v4.For the merchant experience, we deeply integrated Circle Web3 Services (W3S). Every merchant gets a non-custodial Smart Contract Account (SCA). We used the @circle-fin/w3s-pw-web-sdk to handle PIN challenges for high-stakes actions like Payroll and Sweeps, ensuring security without sacrificing UX. The backend (/api/circle/wallet) orchestrates these complex flows, including a robust polling system to sync on-chain state with our PostgreSQL database (Neon/Prisma).Finally, we integrated Google's Gemini AI to build the Treasury Agent. By feeding the agent real-time context (wallet balances, open invoices), we allow merchants to manage their finances ("Pay all open requests") through a simple chat interface, bridging the gap between complex blockchain operations and everyday business needs.