export interface AppAttachment {
    kind: "image" | "video" | "file";
    name: string;
    mediaType: string;
    /** base64 (no data: prefix). */
    data: string;
}
export interface PreparedAttachment extends AppAttachment {
    path?: string;
}
export declare function prepareAttachments(cwd: string, attachments: AppAttachment[]): Promise<PreparedAttachment[]>;