Catala — Law-as-Code Language
A domain-specific language for translating statutory and regulatory text into correct, auditable executable code, pairing lawyers and programmers.
Catala
Catala is a programming language designed to faithfully encode legislative and regulatory text — tax codes, benefits rules, statutes — into executable, auditable code. Developed by researchers at Inria, it uses a literate-programming style so each block of code sits next to the exact legal article it implements, letting lawyers and developers co-review the logic. It has been used to reimplement portions of the French and U.S. tax codes.
Key features
- Literate syntax pairing legal text with its executable implementation
- Default-logic semantics that mirror how statutes express rules and exceptions
- Compiles to general-purpose languages including OCaml, Python, and C
- Prioritizes correctness, traceability, and auditability of legal rules
- Backed by peer-reviewed research on computational law
Legal engineers write Catala programs that mirror statute structure, then compile them into libraries other systems call to compute benefits, taxes, or eligibility with a clear audit trail back to the law.
Curated mirror of the open-source Catala (Apache-2.0). Get it from the source.