BitcoinOS (BOS) is a smart contract operating system for Bitcoin that enables scalability, programmability, and interoperability without altering Bitcoin’s core consensus. It uses zero-knowledge proofs (via BitSNARK) to verify off-chain computations directly on Bitcoin, allowing developers to build DeFi, rollups, and programmable assets secured by Bitcoin itself. Through its Grail protocol, BOS also enables trustless movement of BTC across rollups and other chains, eliminating the need for custodial bridges. The system functions as a decentralized, open-source infrastructure layer that extends Bitcoin’s capabilities while preserving its security, neutrality, and decentralization.