Unichain is an Ethereum L2 optimized for DeFi, and designed to be the home of liquidity across chains. Unichain is an Ethereum Layer 2 platform that focuses on cost-efficiency and liquidity. It offers faster and cheaper transactions, with block times of just one second. It also aims to reduce transaction costs by 20x when compared to Ethereum. It is built on the OP Stack and promotes scalability. Open-source innovations are also promoted, as well as future enhancements such as Provable Block Building. Unichain is a resource for developers and users of the DeFi ecosystem, offering resources to deploy smart contracts and create liquidity pools. Our experience in building the largest decentralized trading platform in the world has informed our design. Unichain is based on the OP stack. Unichain's technical innovations are open source and available to any rollup. A network of full-nodes monitors and validates the actions of the Sequencer, bringing faster transactions to Unichain and more decentralization.