OptionalfallbacksModels tried next if this one fails, when fallback_on_error is on.
The model the request would run on. The server sends null when the key's cap is used up and the request would be refused.
What decided it: <condition>:<value> for a rule, or default, requested, cache, on_empty or budget_exceeded. The server sends null when the request is not routed and runs the model it named.
True when the route policy picked the model, false when the request runs the model it named or is refused.
The answer from POST /key/route/test.