/**
 * Pure converters from multimodal content parts into native Anthropic
 * Messages-API content blocks (image / document).
 *
 * Two input shapes reach the native Anthropic surface:
 *
 *  1. NeuroLink/V3 multimodal parts — `{ type: "image", image }` produced by
 *     the multimodal message builder (base64, data URL, https URL, or bytes).
 *
 *  2. AI-SDK LanguageModel prompt parts — `{ type: "file", mediaType, data }`.
 *     This is how `ai@6` encodes BOTH images and PDFs in the prompt that the
 *     provider's `doGenerate(options.prompt)` receives. Before this module the
 *     converter only handled `type:"image"`, so on the tool-using generate
 *     path (which always normalises images to `type:"file"`) the image part
 *     was silently dropped — the model never saw the image ("no image
 *     detected"). Gemini/Vertex are immune because they read `input.images`
 *     directly in their own builders instead of going through this conversion.
 *
 * Media type is taken from the AI-SDK-provided `mediaType` when present, then
 * sniffed from magic bytes, and only then defaulted — a hardcoded `image/png`
 * default silently corrupts JPEG/GIF/WebP uploads (the Anthropic API rejects a
 * mislabeled base64 image with HTTP 400 and the image vanishes).
 */
import type Anthropic from "@anthropic-ai/sdk";
/**
 * Detect a supported image media type from a buffer's magic bytes. Returns
 * undefined when the bytes are not one of the four Anthropic-supported formats.
 */
export declare function sniffImageMediaType(bytes: Uint8Array): Anthropic.Messages.Base64ImageSource["media_type"] | undefined;
/**
 * Convert an image part (data URL, bare base64, https URL, byte array, or
 * ArrayBuffer) into an Anthropic image block. Honors `mediaTypeHint` (the
 * AI-SDK `mediaType`), falls back to magic-byte sniffing, then to image/png.
 * Returns undefined for unusable inputs.
 */
export declare function toAnthropicImageBlock(data: unknown, mediaTypeHint?: string): Anthropic.Messages.ImageBlockParam | undefined;
/**
 * Convert an AI-SDK `{ type: "file", mediaType, data }` content part into the
 * matching Anthropic content block: image/* → image block (media type honored,
 * not hardcoded), application/pdf → document block. Returns undefined for
 * unsupported media types (so the caller simply omits them rather than 400ing).
 * When `mediaType` is absent, image bytes are still salvaged via sniffing.
 */
export declare function fileToAnthropicBlock(part: {
    mediaType?: string;
    data?: unknown;
}): Anthropic.Messages.ContentBlockParam | undefined;