/**
 * Standards-compliant 1D barcode encoder (Code 128, EAN-13, EAN-8, UPC-A).
 * Generates module runs suitable for SVG rendering. No external deps.
 */
export type BarcodeSymbology = 'code128' | 'ean13' | 'ean8' | 'upc_a';
export type BarcodeRun = {
    x: number;
    w: number;
    black: boolean;
};
export type EncodedBarcode = {
    format: BarcodeSymbology;
    text: string;
    runs: BarcodeRun[];
    modules: number;
};
/** GS1 check digit for a payload without the check (odd positions from the right × 3). */
export declare function gs1CheckDigit(payload: string): number;
export declare function isValidGs1(digits: string): boolean;
export declare function encodeBarcode(value: string, format?: 'auto' | BarcodeSymbology): EncodedBarcode | null;