/**
 * Sent immediately after the connection is accepted. The `config` block
 * echoes the resolved surface. Note that the endpointing field is echoed as
 * `turn_detection` (`vad` / `manual`), not `endpointing`.
 */
export interface RealtimeSessionBegin {
    event: "session.begin";
    /** Per-connection correlation id (quote it in support/debugging) */
    request_id: string;
    /** Resolved server-side session configuration */
    config?: RealtimeSessionBegin.Config | undefined;
}
export declare namespace RealtimeSessionBegin {
    /**
     * Resolved server-side session configuration
     */
    interface Config {
        model?: string | undefined;
        language_code?: string | undefined;
        encoding?: string | undefined;
        sample_rate?: number | undefined;
        stream_type?: string | undefined;
        mode?: string | undefined;
        prompt?: string | undefined;
        /** Endpointing strategy, echoed as turn_detection (vad / manual) */
        turn_detection?: string | undefined;
        threshold?: number | undefined;
        prefix_padding_ms?: number | undefined;
        silence_duration_ms?: number | undefined;
        min_speech_duration_ms?: number | undefined;
        return_timestamps?: boolean | undefined;
    }
}