# SFT Engine Contract

SFT is treated as an artifact-producing engine.

Given a proposed witness context (arena slice, phase observable, coupling class, and perturbation model), the engine outputs exactly one of:

- a Witness Stability Certificate (WSC), or
- a Witness Obstruction (WOB)

The intent is to make universality claims referee-hard:

- either a witness exists with explicit stability margins
- or a named obstruction exists with evidence and a recommended next move list

This contract is the SFT analogue of the certificate-or-obstruction pipeline used in your RU flagship scope.
