PayMate

PayMate is a programmable credit liquidity pool where licensed Payment Service Providers (PSPs) access instant USDC capital for corridor settlement prefunding, and institutional investors earn a guaranteed 5% fixed APY all on-chain on Arc.

The problem: PSPs pre-fund millions in bank accounts across markets earning zero yield. Cross-border capital takes days. FX spreads eat margins.

PayMate replaces this with an on-chain credit pool. PSPs onboard through a full KYB process with a 14-criteria credit scoring matrix (KYR), get approved by admin, then draw USDC from the pool instantly.
They repay in any stablecoin (USDC, EURC, USDT) , non-USDC repayments are automatically converted via Uniswap. Fees go to a Yield Reserve that funds investor APY.

Investors deposit USDC and earn fixed 5% APY regardless of pool utilization. Yield is distributed every 7 days automatically by a Chainlink CRE workflow.

If the pool lacks liquidity for a drawdown, CRE sources USDC from Uniswap across chains. Before every drawdown, autonomous AI agents pay for credit risk data via Circle Nanopayments , real gas-free
micropayments on Arc using the x402 protocol. One agent buys market data, processes it, and sells its analysis to other agents — genuine agent-to-agent commerce.

Smart contracts are deployed on Arc testnet with real USDC/EURC. Full fund flow verified: deposit → drawdown → repay → fee routing → yield distribution → withdrawal.

Smart contracts (Solidity 0.8.24) deployed on Arc testnet via Hardhat, Pool.sol handles deposits, drawdowns, repayments with conditional shortfall handling. YieldReserve.sol isolates fees from principal. Pool.sol imports Chainlink's AggregatorV3Interface for on-chain EURC/USD price verification. Contracts use OpenZeppelin AccessControl for role-based permissions (ADMIN_ROLE, CRE_ROLE) and SafeERC20 for
token safety.

Backend is Node.js/Express with MongoDB. Handles auth (JWT + bcrypt), PSP KYB onboarding with 25+ fields, 14-criteria KYR credit scoring with rating bands (AAA/AA/A/B), LP deposit/withdraw tracking,
drawdown validation, audit logging. Has a Uniswap rate API that calls the Trading API /quote endpoint to show live EURC/USDC conversion rates. Event listener service syncs on-chain state to DB via ethers.js.

Chainlink CRE workflow (TypeScript, compiled to WASM) has 3 handlers: cron-triggered yield distribution every 7 days, EVM log trigger for liquidity shortfalls (calls Uniswap API via Confidential HTTP to
hide API credentials in enclave), and EVM log trigger for non-USDC repayment conversion. Uses Chainlink Price Feeds to verify Uniswap quotes. All 3 simulations pass via CRE CLI.

Nanopayment agent layer uses @circle-fin/x402-batching on Arc testnet. 4 agents: Data Service (sell side, 3 x402-protected endpoints), Pool Monitor (buys market data AND sells pool analysis, agent-to-agent commerce), Credit Risk Agent (pays $0.018 per PSP assessment across 3 data sources), Repayment Reminder Agent. Real USDC payments verified on Arc, started with 5 USDC, spent $0.022 across 5 paid API calls.

Frontend is Next.js 16 with Tailwind CSS and shadcn/ui. wagmi + RainbowKit for wallet connection on Arc testnet. 11 pages including multi-step KYB onboarding, PSP dashboard with drawdown/repay/history, LP
dashboard with deposit/withdraw/pool overview, admin dashboard with KYR scoring panel. Live Uniswap rates displayed on repay and deposit pages. On-chain reads via custom wagmi hooks (usePoolState, useLPBalance, usePSPPosition).

Uniswap Trading API integrated across 4 touchpoints: CRE shortfall handler, CRE repayment conversion, backend rate API, and frontend quote preview , all with authenticated API key.