The adapter Tier 1 runs first and the seam's tests bind. Its rules are a table in an Agent, one per test. A test binds it through the configuration override as {Mediate.Test.Fake, rules: pid}. An entry allows one holder one operation on one object or on any object of a type. A holder is one subject, an account whatever its kind, or any subject. The fake allows nothing else.

Without a table the fake answers with the verdict option, which is :deny unless the test says otherwise.

It returns a value of the real type everywhere the real adapters do. scope returns a real dynamic. A table told to fail/2 answers every call with the reason :engine_unreachable, so the port's fail-closed path runs against it.