Provider Runtime
Phase IV · V4 — Given an authorized BrokerGrant, which provider executes it and how is that execution routed and planned, independently of any provider, without executing anything? A deterministic planner: provider registry, capability matching, selection, failover. Executes nothing (V5 executes the plan). Read-only.
The Universal Provider Runtime consumes an authorized BrokerGrant (V3) and produces a ProviderExecutionPlan: it verifies the grant (binding, unexpired, unexecuted), then filters every provider by required capabilities, context limit, cost class, availability, enterprise restrictions, and allow/deny lists — recording each exclusion — and ranks survivors deterministically (preference → priority → cost → id) into a selected provider plus an ordered failover chain. Fail-closed: an unresolved or denied or expired grant denies; no satisfying provider is unroutable. It calls no APIs, invokes no models, performs no inference, opens no network, and holds no credentials; providers are metadata and providerRef is always deferred. The future Execution Runtime (V5) consumes the plan.