import type { UIMessage } from "ai";
/** A picked File → an ai-SDK FileUIPart (data URL) so it can ride the turn.
    The optional `onProgress` (0..1) feeds the chip's read ring:
    attachments are now read eagerly at attach time (progress visible, failures
    surfaced per-chip with retry) instead of silently at send time. */
export declare function fileToPart(file: File, onProgress?: (fraction: number) => void): Promise<{
    type: "file";
    mediaType: string;
    filename: string;
    url: string;
}>;
/** The `.fl-att-ext` badge text — the filename's extension, bounded so a long
    or missing one still reads as a badge. */
export declare function fileExt(name: string | undefined): string;
export declare function formatBytes(size: number): string;
export type FilePart = Extract<UIMessage["parts"][number], {
    type: "file";
}>;
/** A part that names a file the SERVER holds rather than carrying it: the
    conversation's own files, a drop still in staging, or the keep-shelf. All
    three live under §3.1's frozen `/user` mount, and nothing that carries its own
    bytes ever does — a data:, blob: or https: url cannot start with a slash. */
export declare const isSavedFile: (url: string) => boolean;
/** A sent attachment in the transcript: images render as the designed
    `.fl-msg-img` thumbnail, anything else as a `.fl-msg-file` pill.

    A SAVED file is a reference, not bytes in the transcript — it lives in the
    user's own files — so its pill names it and has nothing to download. Only a
    part still carrying its own data keeps the download link. */
export declare function SentAttachment({ part }: {
    part: FilePart;
}): import("react").JSX.Element;