I introduce Vessel, a programming language whose type system, operational semantics, and concurrency model are derived directly from the four axioms of Scale Calculus (M1-M4) and the fundamental identity T-H1: alpha = ln(kappa), equivalently kappa = e^alpha. Types are kappa ranges partitioned by the forbidden zone. The call stack is alpha arithmetic. Scope is the boundary operator dV. Concurrency is Phi = 0 maintenance. Errors are DRC violations. I present a formal grammar, kappa inference rules, operational semantics, a soundness theorem, a five-module standard library, and five full program examples. Four open problems are identified for future work