/**
 * fallbackProvider — convenience for chained fallbacks across N providers.
 *
 * Pattern: Chain of Responsibility (GoF) over `LLMProvider` instances.
 * Role:    Outer ring (Hexagonal). Sugar over repeated `withFallback`.
 *
 * `fallbackProvider(p1, p2, p3)` is equivalent to
 * `withFallback(p1, withFallback(p2, p3))` — tries each provider in
 * order, advancing on errors that match the (optional) shouldFallback
 * predicate. The first success wins; if all fail, the last error throws.
 *
 * @example
 *   import { anthropic, openai, mock } from 'agentfootprint/providers';
 *   import { fallbackProvider } from 'agentfootprint/resilience';
 *
 *   const provider = fallbackProvider(
 *     anthropic({ apiKey: A }),
 *     openai({ apiKey: O }),
 *     mock({ reply: '[degraded] all upstream providers failed' }),
 *   );
 */
import type { LLMProvider } from '../provider-contract/types.js';
import { type WithFallbackOptions } from './withFallback.js';
export interface FallbackProviderOptions extends WithFallbackOptions {
    /** Optional explicit name for the chained provider. */
    readonly name?: string;
}
/**
 * Compose N providers into a single fallback chain. At least one
 * provider is required; throws synchronously on empty input.
 */
export declare function fallbackProvider(...providers: readonly LLMProvider[]): LLMProvider;
export declare function fallbackProvider(options: FallbackProviderOptions, ...providers: readonly LLMProvider[]): LLMProvider;