PayFi (Payment Finance) is an innovative model that combines payment features with financial services using blockchain technology and smart contracts. PayFi uses blockchain as a settlement layer at its core, merging Web3 payments with decentralized finance (DeFi) to enable smooth, efficient value transfers. PayFi aims to fulfill the Bitcoin whitepaper's vision: creating a peer-to-peer electronic cash payment network that doesn't need trusted third parties while using DeFi's capabilities to build a new financial ecosystem.