import { STT, LLM, TTS } from './providers.js';
/** Default seconds a failing provider is skipped before being retried. */
export declare const DEFAULT_TEMPORARY_DISABLE_SEC = 60;
/** Default number of failed attempts after which a provider is disabled for the session. */
export declare const DEFAULT_PERMANENT_DISABLE_AFTER_ATTEMPTS = 3;
/** Default seconds between background health checks of a disabled provider. */
export declare const DEFAULT_RECOVERY_CHECK_INTERVAL_SEC = 300;
/** Failover tuning options shared by all fallback providers. */
export type FallbackOptions = {
    /** Seconds to skip a failing provider before retrying. Defaults to {@link DEFAULT_TEMPORARY_DISABLE_SEC}. */
    temporaryDisableSec?: number;
    /** Failed attempts after which a provider is disabled for the session. Defaults to {@link DEFAULT_PERMANENT_DISABLE_AFTER_ATTEMPTS}. */
    permanentDisableAfterAttempts?: number;
    /** Seconds between health checks of a disabled provider. Defaults to {@link DEFAULT_RECOVERY_CHECK_INTERVAL_SEC}. */
    recoveryCheckIntervalSec?: number;
    /**
     * Latency ceiling in ms for the active provider. When exceeded for
     * `consecutiveLatencyHits` turns in a row, the chain fails over. Omitted/0 = disabled.
     */
    latencyThresholdMs?: number | null;
    /** Consecutive turns over `latencyThresholdMs` before failing over. Defaults to 3. */
    consecutiveLatencyHits?: number;
    /** Additional provider-specific options, passed through unchanged. */
    [key: string]: any;
};
declare class FallbackSTTImpl extends STT {
    _providerName: string;
    providers: STT[];
    protected _primary: STT | null;
    protected _temporaryDisableSec: number;
    protected _permanentDisableAfterAttempts: number;
    protected _recoveryCheckIntervalSec: number;
    protected _latencyThresholdMs: number | null;
    protected _consecutiveLatencyHits: number;
    constructor(providers: STT[], opts?: FallbackOptions);
    getRuntimeConfig(): Record<string, any>;
}
/** A speech-to-text provider that fails over across an ordered list of {@link STT} providers. */
export type FallbackSTT = FallbackSTTImpl;
/**
 * Create an {@link STT} provider that tries each provider in order, failing over
 * to the next when one is unavailable.
 * @param providers - Providers in priority order; the first is the primary.
 * @param opts - Failover tuning. See {@link FallbackOptions}.
 */
export declare const FallbackSTT: (providers: STT[], opts?: FallbackOptions) => FallbackSTT;
declare class FallbackLLMImpl extends LLM {
    _providerName: string;
    providers: LLM[];
    protected _primary: LLM | null;
    protected _temporaryDisableSec: number;
    protected _permanentDisableAfterAttempts: number;
    protected _recoveryCheckIntervalSec: number;
    protected _latencyThresholdMs: number | null;
    protected _consecutiveLatencyHits: number;
    constructor(providers: LLM[], opts?: FallbackOptions);
    getRuntimeConfig(): Record<string, any>;
}
/** An LLM provider that fails over across an ordered list of {@link LLM} providers. */
export type FallbackLLM = FallbackLLMImpl;
/**
 * Create an {@link LLM} provider that tries each provider in order, failing over
 * to the next when one is unavailable. The primary's `temperature` and
 * `max_output_tokens` settings carry through.
 * @param providers - Providers in priority order; the first is the primary.
 * @param opts - Failover tuning. See {@link FallbackOptions}.
 */
export declare const FallbackLLM: (providers: LLM[], opts?: FallbackOptions) => FallbackLLM;
declare class FallbackTTSImpl extends TTS {
    _providerName: string;
    providers: TTS[];
    protected _primary: TTS | null;
    protected _temporaryDisableSec: number;
    protected _permanentDisableAfterAttempts: number;
    protected _recoveryCheckIntervalSec: number;
    protected _latencyThresholdMs: number | null;
    protected _consecutiveLatencyHits: number;
    constructor(providers: TTS[], opts?: FallbackOptions);
    getRuntimeConfig(): Record<string, any>;
}
/** A text-to-speech provider that fails over across an ordered list of {@link TTS} providers. */
export type FallbackTTS = FallbackTTSImpl;
/**
 * Create a {@link TTS} provider that tries each provider in order, failing over
 * to the next when one is unavailable.
 * @param providers - Providers in priority order; the first is the primary.
 * @param opts - Failover tuning. See {@link FallbackOptions}.
 */
export declare const FallbackTTS: (providers: TTS[], opts?: FallbackOptions) => FallbackTTS;
export {};