import type { AttachmentAdapter, CompleteAttachment, PendingAttachment } from "@assistant-ui/react";
export declare const MAX_PDF_BYTES: number;
export declare const MAX_IMAGE_BYTES: number;
export declare const MAX_IMAGE_DIMENSION = 2048;
export declare const MAX_ESTIMATED_BODY_BYTES: number;
export declare const AGGRESSIVE_MAX_IMAGE_DIMENSION = 1024;
export declare const AGGRESSIVE_JPEG_QUALITY = 0.7;
export declare function inferDocumentContentType(file: File): string;
export declare function getFileDataURL(file: File | Blob): Promise<string>;
/**
 * Transcode an image to a web-safe JPEG or PNG via canvas and return its
 * data-URL. Throws if canvas is unavailable.
 */
export declare function transcodeImageToDataURL(file: File, opts?: {
    maxDimension?: number;
    jpegQuality?: number;
}): Promise<string>;
/**
 * Return a web-safe, size-bounded data-URL for an image file.
 *
 * - Always transcodes formats that vision APIs reject (HEIC, TIFF, AVIF, BMP, …)
 *   to JPEG/PNG via canvas, regardless of file size.
 * - Also downscales files over MAX_IMAGE_BYTES so large screenshots/photos
 *   don't blow up the request body.
 * - Throws (does NOT silently fall back) when the format is non-web-safe and
 *   canvas transcoding fails — the adapter should surface a visible error.
 */
export declare function getImageFileDataURL(file: File): Promise<string>;
/**
 * Estimate the serialized byte cost of a collection of attachment data-URLs
 * (base64 strings, accounting for JSON string escaping overhead).
 */
export declare function estimateAttachmentBodyBytes(dataUrls: string[]): number;
export type QueuedAttachment = CompleteAttachment;
export declare class DownscalingImageAttachmentAdapter implements AttachmentAdapter {
    accept: string;
    add(state: {
        file: File;
    }): Promise<PendingAttachment>;
    send(attachment: PendingAttachment): Promise<CompleteAttachment>;
    remove(): Promise<void>;
}
export declare class BinaryDocumentAttachmentAdapter implements AttachmentAdapter {
    accept: string;
    add(state: {
        file: File;
    }): Promise<PendingAttachment>;
    send(attachment: PendingAttachment): Promise<CompleteAttachment>;
    remove(): Promise<void>;
}
export declare function imageContentTypeFromDataUrl(dataUrl: string): string;
export declare function imageExtensionFromContentType(contentType: string): string;
export declare function createAgentImageAttachments(images?: readonly string[]): QueuedAttachment[] | undefined;
export declare function isTextLikeFile(file: File): boolean;
export declare function textFileAttachmentEnvelope(file: File, text: string): string;
export declare function serializeAttachmentContentPart(part: Record<string, unknown>): QueuedAttachment["content"][number] | null;
export declare function serializeQueuedAttachments(attachments?: ReadonlyArray<unknown>): Promise<QueuedAttachment[] | undefined>;
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