/** A leveled logger that writes formatted lines to stdout. */
export type Logger = {
    /** Logger name shown in each log line. */
    readonly name: string;
    /** Minimum level to emit, as a name (e.g. `'INFO'`) or numeric threshold. */
    level: string | number;
    /** Whether to propagate to parent loggers (unused; kept for compatibility). */
    propagate: boolean;
    /** Log at DEBUG level. */
    debug(message: unknown, ...args: unknown[]): void;
    /** Log at INFO level. */
    info(message: unknown, ...args: unknown[]): void;
    /** Log at WARNING level. */
    warning(message: unknown, ...args: unknown[]): void;
    /** Log at WARNING level (alias of {@link Logger.warning}). */
    warn(message: unknown, ...args: unknown[]): void;
    /** Log at ERROR level. */
    error(message: unknown, ...args: unknown[]): void;
    /** Set the minimum level to emit. */
    setLevel(level: string | number): void;
};
/**
 * Configure and return the shared `zrt.agents` {@link Logger}.
 * @param level Minimum level to emit. Default: `'INFO'`.
 */
export declare function setupLogging(level?: string | number): Logger;
/** An in-memory cache of pre-rendered TTS audio buffers, keyed by string. */
export declare class TTSAudioCache {
    private files;
    constructor(..._a: unknown[]);
    /** Store `data` under `key`, replacing any existing entry. */
    add(key: string, data: Buffer): void;
    /** Return the buffer cached under `key`, or `undefined` if absent. */
    get(key: string): Buffer | undefined;
    /** Remove all cached entries. */
    clear(): void;
    /** Whether a buffer is cached under `key`. */
    has(key: string): boolean;
}
/**
 * Read an audio file into a Buffer. Returns an empty Buffer if the file is
 * missing, a directory, or unreadable; other errors are rethrown.
 */
export declare function loadAudioFile(path: string): Buffer;