import type { LanguageModelV2, LanguageModelV3 } from "@ai-sdk/provider";
import { type ProviderFallbackPolicy } from "./fallback-policy";
/** Concrete model type (excludes string model IDs from the LanguageModel union). */
type ConcreteLanguageModel = LanguageModelV2 | LanguageModelV3;
export interface FallbackProvider {
    name: string;
    model: ConcreteLanguageModel;
}
/**
 * Wraps multiple LanguageModel instances and automatically fails over to
 * backup providers when the primary returns retryable errors (429/500/503).
 *
 * Config errors (400/401/403) are thrown immediately — they indicate
 * misconfiguration, not transient failures.
 */
export declare class FallbackLanguageModel {
    readonly specificationVersion: string;
    readonly provider: string;
    readonly modelId: string;
    readonly supportedUrls: ConcreteLanguageModel["supportedUrls"];
    private providers;
    private policy;
    constructor(providers: FallbackProvider[], policy?: ProviderFallbackPolicy);
    doGenerate(options: unknown): Promise<unknown>;
    doStream(options: unknown): Promise<unknown>;
}
export {};
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