import type { Config } from '../../config/schema.js';
export type WebchatTtsResult = {
    type: 'tts_audio';
    uri: string;
    mimeType: string;
    name: string;
};
export type WebchatTtsDeps = {
    config: Config | undefined;
    getLastAssistantPlainText: (conversationId: string) => string;
    log: {
        warn: (obj: Record<string, unknown>, msg: string) => void;
    };
};
/** True when the explicit TTS tool already produced durable Webchat audio. */
export declare function isSuccessfulWebchatTtsToolEvent(event: unknown): boolean;
/**
 * Generate TTS for webchat when config allows; persist under `{stateDir}/media/tts/`.
 */
export declare function maybeEmitWebchatTts(deps: WebchatTtsDeps, conversationId: string, hadInboundVoice: boolean): Promise<WebchatTtsResult | null>;