Drafting computable contracts: executable representations of legal agreements

Computable contracts aim to express the terms of legal agreements in a form that computers can interpret and execute. While their roots predate distributed ledger technologies, the rise of blockchain has renewed interest in this domain through the concept of “smart contracts”, although this term has been misinterpreted and has lost its original connection with the legal dimension. After providing a conceptual background that clarifies common misinterpretations and disambiguates overlapping terms in this domain—such as smart contracts, e-contracts, or computable contracts—this thesis ultimately focuses on the latter. This dissertation investigates how contract terms can be represented in a computable form such that the behaviour of the computable contract remains faithful to the legal semantics of the agreement. This research question is addressed along two complementary lines of inquiry. First, the thesis explores the design of a domain-specific language for computable contracts that preserves legal meaning while supporting execution in digital environments. This results in the implemen-tation of the Stipula language, whose specific features reflect key contract elements such as obligations, amendment clauses or statutorily implied terms. Second, it examines how different programming paradigms—particularly logic-declarative and object-oriented imperative approaches—perform in modelling computable con tracts, including Stipula, through a comparative framework grounded in a real world case study on data-sharing agreements under the EU Data Act. The findings show that no single paradigm fully captures the complexity of computable contracting: declarative approaches align more closely with normative reasoning, whereas imperative approaches provide stronger operational con-trol. Although domain-specific solutions offer important benefits, the thesis suggests that hybrid and layered language architectures are a promising direction for unifying legal semantics and computational automation.