/**
 * Voice-note speech-to-text (OpenAI transcription).
 *
 * Same injection shape as `synthesize.ts`: the client, model and clamp come
 * from the host, so nothing here reads env or imports a transport.
 *
 * Contract mirrors the synthesizer: null on ANY failure (disabled, empty
 * audio, API error, empty transcript), never a throw — callers fall back to a
 * text reply rather than silence.
 *
 * `openai` is only ever imported as a type. The upload is built from the
 * platform `File` global rather than the SDK's `toFile` helper, which would be
 * a value import and make an optional peer dependency load-bearing at module
 * load time.
 */
import type OpenAI from "openai";
export interface TranscriberConfig {
    /** Lazy OpenAI client — injected so this module never reads env. */
    client: () => OpenAI;
    /** Master gate; false makes the transcriber a no-op null. */
    enabled: () => boolean;
    /** Transcription model. */
    model?: string;
    /** Clamp on the returned transcript before it enters the answer path. */
    maxChars?: number;
}
export declare const DEFAULT_TRANSCRIPT_MAX_CHARS = 2000;
/** Transcribe audio bytes, or null when no usable transcript came back. */
export type Transcriber = (bytes: Uint8Array) => Promise<string | null>;
/**
 * Build a transcriber: Ogg/Opus bytes → transcript | null.
 *
 * The model auto-detects the spoken language, so no language hint is needed.
 */
export declare function createTranscriber(config: TranscriberConfig): Transcriber;