Statebox is a radically different way to build smart contracts, inspired by modern physics and mathematics. Instead of text-based instructions telling a smart contract how to achieve certain behaviour, statebox contracts are represented as diagrams. End-to-end correctness proofs are a fundamental design principle, not an afterthought: the core is a mathematically minimalistic structure, aimed to facilitate reasoning about its behaviour. As a result, diagrams can be composed into bigger diagrams, preserving their properties, such as termination guarantees. This way contracts become easier to understand, build and inspect.