VOI Frontier and Method Maturity

Stable promotion requires cross-language parity and Rust-kernel parity in addition to the method-specific evidence described below.

The VOI frontier catalogue records methods that extend the stable Rust-backed kernel. A method may be useful and documented without being a v1 stable guarantee.

Maturity labels

• Stable methods are covered by the versioned stable API and compatibility policy.
• Fixture-backed methods have deterministic contract fixtures but still need broader evidence before promotion.
• Experimental methods are isolated under voiage.experimental or an explicitly labelled method surface and may change without stable API guarantees.

Promotion requires contract validation, provenance, reproducibility, security review, and—where relevant—cross-language parity and licensed evidence. See the migration guide before depending on a fixture-backed or experimental method in production.

Expected-utility information pricing

The EUI, CEI, BPI, SPI, and anchored PPI family is implemented as an experimental Rust kernel with a Python/PyO3 facade and deterministic frontier fixtures. Value of Clairvoyance is a presentation of its clairvoyant-policy result, not a duplicate method. A monetary EVPI alias is available only after positive-affine reduction; nonlinear utility results are not relabelled.

R and Julia support is currently absent, and Mojo remains an external boundary. Scientific review, hosted assurance, and a separate promotion decision remain open; implementation and documentation do not make this a stable method. See the method contract for interpretation and diagnostics.