A module's contract should be the thing you would hand a new teammate — why this exists, what it promises, what must stay true — and it should be impossible for that document to quietly stop being true. SpecSync makes the written record and the code answer to each other: the check fails when they disagree, and the change workflow makes sure a contract only moves when a person agreed it should. It should feel like a fast local command you keep in your inner loop rather than a process you submit to, and it should never need a key, a hosted service or a model to do its job. When a change closes, the reasoning and the evidence stay in the repository beside the code, for whoever comes next.