Unipay.exchange

Problem Statement

Unipay.Exchange is the 1st FIAT to DeFi onramp using UPI payments to make the vast liquidity available to the masses. The platform allows users to purchase cryptocurrencies directly in their native form by just scanning a UPI QR code and making an INR payment—no complicated onboarding, no centralized custody.The platform leverages Uniswap V4 hooks to facilitate the transaction via a treasury and Pyth Network’s real-time price feeds to ensure transparent INR-to-crypto conversion rates verified on-chain!With Unipay.Exchange, anyone can move from fiat to crypto in seconds, making Web3 truly accessible to the everyday user while maintaining the security and transparency of on-chain settlement.

Solution

A relayer-orchestrated system that enables users to buy crypto with fiat payments while guaranteeing exchange rates through oracle price locks and sophisticated onchain execution.Technical ArchitecturePrice Lock MechanismPyth Oracle locks ETH/USDC rates with expiry timestampsReturns quoteId that cryptographically binds price, amount, and deadlinePrevents slippage between fiat payment and crypto deliveryPayment-to-NFT BridgeUser pays 500 INR via UPI GatewayRelayer mints ReceiptNFT with tokenId=txnId and metadata={quoteId}NFT serves as onchain proof-of-payment with embedded rate guaranteeRelayer transfers NFT to TreasuryHook (custody for execution)Hook-Based Execution EngineUniswap v4 Hook validates and executes swaps atomicallyExtracts quoteId from NFT metadata.Validates locked quote with Oracle (price, expiry, unused status)Burns NFT to prevent double-spendingCalculates exact swap amounts using locked ratePoolManager executes ETH→USDC swap with guaranteed outputERC-6909 claims track user's USDC balanceUser can withdraw to any wallet when ready