KeyChain builds a user-owned, censorship-resistant, and seamless cross-chain Web3 gateway through a hybrid DEX engine (AMM + order book + AI slippage optimization), quantum-safe wallet (MPC + SPHINCS++ hardware SE), and chain-abstracted accounts (unified management of 30+ chain assets). KeyChain applications collectively form the 'golden triangle' of Web3.0 infrastructure—trusted computing layer (bridging the physical world), value exchange layer (DEX/credit protocols), and asset digitization layer (RWA/ownership certificates). The technological breakthrough lies in the collaborative evolution of scalability and modular blockchains. KeyChain opens the key to the blockchain and the future world for everyone, while the KEY public chain builds a permissionless blockchain suitable for applications for institutions and developers, making wallets and financial tools more accessible without compromising the core principle of decentralization. The KEY chain will construct a self-evolving, infinitely scalable, and seamlessly connecting blockchain foundation layer between the real and digital worlds, becoming the core engine for humanity's move towards a trusted digital society. By combining cutting-edge academic achievements (such as quantum security and federated learning) with extreme engineering design, the KEY chain redefines the boundaries of public chain possibilities. #key