go-api-contractlisted

# Go API Contract A public API is an **observable contract**: every distinction a deployed client can detect is a clause. `request acceptance -> success -> failure -> replay or async recovery -> compatibility -> proof` For a delegated Decision or Review, or when the active artifact requires its result interface, load the [shared specialist contract](../../contracts/specialist-contract.md). For each affected operation, build one `ObservableCell{surface, old, accepted, client_consequence, owner, proof}` matrix from `api/openapi/service.yaml`, the serving router, `internal/problem`, and affected consumers. Each changed cell names the old behavior, accepted behavior, client consequence, canonical owner, and proof. Status, body shape or absence, error code and details, default and nullability, pagination order and cursor, resource identity, retry outcome, and unknown mutation outcome are observables. A green schema diff proves syntax, not compatibility. A Decision fills every missing cell and its migration behavior. A Review tries to falsify every accepted cell through a client-visible example. Complete only when every changed observable has one stable clause and consumer-runnable proof or a named evidence gap. The scope starts at the changed published operation and closes only after every terminal, replay, and unknown-outcome state that a client can distinguish. Load the [reference selector](references/index.md) only for its stated pressure.