/** Pure extension-based MIME defaults for the sandbox file tools. */
import type { MimeResolver } from "../contracts/mime_resolver";
/** The default prefix available to a custom resolver. */
export declare const DEFAULT_MIME_PEEK_BYTES = 512;
/** Extension to MIME mappings used by the default resolver. */
export declare const SANDBOX_EXTENSION_MIME: Readonly<Record<string, string>>;
/** Resolve a MIME type from a filename, without sniffing bytes. */
export declare const extensionMimeResolver: MimeResolver;
/** The default resolver, also exported under the concise name used by consumers. */
export declare const defaultMimeResolver: MimeResolver;
/**
 * Run a resolver and fall back to the extension resolver when it declines.
 * The callback supplied to consumer code is always bounded by `maxPeekBytes`.
 */
export declare const resolveMime: (path: string, resolver?: MimeResolver, options?: {
    declared?: string;
    maxPeekBytes?: number;
    peek?: (bytes: number) => Promise<Uint8Array>;
}) => Promise<string | undefined>;