export type MessageRenderMode = 'tty' | 'plain';
export interface MessageRenderOptions {
    mode: MessageRenderMode;
    /**
     * Optional override. When `true`, the renderer returns the input unchanged
     * regardless of `mode`. Callers should set this when `NO_COLOR` is set,
     * `--no-color` is passed, or `--json` is requested.
     */
    noColor?: boolean;
}
/**
 * Render a human-readable message string for the terminal.
 *
 * Pure function. Returns the input unchanged when:
 *   - `input` is empty,
 *   - `input` is not a string (defensive: callers occasionally pass numbers/objects),
 *   - `mode === 'plain'`,
 *   - `noColor === true` (NO_COLOR / --no-color / --json opt-out).
 */
export declare function renderMessage(input: string, options: MessageRenderOptions): string;