/**
 * Typed fallback and degradation.
 *
 * Fallback triggers are typed: no fuzzy substitution, no surprise paid
 * provider, local-only preserved, safety class preserved, fallback reason and
 * cost implications visible, loops bounded, and no silent quality downgrade.
 *
 * Fallback hierarchy:
 *   explicit operator fallback → validated policy fallback →
 *   deterministic baseline → safe degraded mode → typed blocked state.
 */
import type { OrchestrationCandidate, OrchestrationFeatureVector } from "./types.js";
export type FallbackTrigger = "provider_unavailable" | "model_unavailable" | "rate_limited" | "context_limit" | "structured_output_invalid" | "tool_capability_unavailable" | "subagent_unavailable" | "evaluation_store_unavailable" | "routing_policy_corrupt";
export interface FallbackResult {
    trigger: FallbackTrigger;
    selectedCandidate?: OrchestrationCandidate;
    fallbackLayer: "operator" | "validated_policy" | "deterministic_baseline" | "degraded" | "blocked";
    reason: string;
    costImplication: string;
    blocked: boolean;
}
/**
 * Resolve a fallback for a trigger.
 * - explicitFallback: operator-provided candidate (highest authority).
 * - policyFallback: candidate from the validated policy.
 * - Otherwise, fall to the deterministic baseline then to a typed degraded mode.
 */
export declare function resolveFallback(trigger: FallbackTrigger, features: OrchestrationFeatureVector, options: {
    explicitFallback?: OrchestrationCandidate;
    policyFallback?: OrchestrationCandidate;
    localOnly: boolean;
    safetyClass: string;
}): FallbackResult;
export declare function isRemoteProvider(provider: string): boolean;
export declare const FALLBACK_CHAIN_LIMIT = 5;
//# sourceMappingURL=fallback.d.ts.map