type BuildMultipartInput = {
    /**
     * JSON-serialisable payload. Goes into the multipart `data` part as a
     * plain JSON-stringified field (see the function-level doc for why it's
     * a string, not a `Blob`). The helper does not inspect the contents —
     * callers are responsible for the wire shape (see `buildCuringRequestData`
     * for the curing case).
     */
    data: unknown;
    /**
     * Optional file to attach as the multipart `file` part. Omitted from the
     * `FormData` when null/undefined — the BE accepts data-only submissions
     * for some flows (e.g. curing's explanation-only correction).
     */
    file?: File | null;
};
/**
 * Build a `FormData` body for a multipart POST. Always appends a `data`
 * part (JSON-serialised, as a plain string — *not* a Blob, otherwise
 * FormData stamps it with a default `filename="blob"` in its
 * Content-Disposition header and the BE's multipart parser (Busboy)
 * routes it to `files.data` instead of `fields.data`. The `fields.data`
 * lookup then returns undefined and the BE responds with 400
 * "Multipart form is missing the required `data` field"). Appends a
 * `file` part only when one is supplied. Curing-agnostic — the
 * curing-shape mapping lives in
 * `widgets/TaxbitCuringDocumentation/buildCuringRequestData.ts`.
 */
export declare const buildMultipart: ({ data, file, }: BuildMultipartInput) => FormData;
export {};