# src/fee-calculator.js

    // @flow
    import * as BufferLayout from 'buffer-layout';

    /**
     * https://github.com/solana-labs/solana/blob/90bedd7e067b5b8f3ddbb45da00a4e9cabb22c62/sdk/src/fee_calculator.rs#L7-L11
     *
     * @private
     */
    export const FeeCalculatorLayout = BufferLayout.nu64('lamportsPerSignature');

    /**
     * @typedef {Object} FeeCalculator
     * @property {number} lamportsPerSignature lamports Cost in lamports to validate a signature
     */
    export type FeeCalculator = {
      lamportsPerSignature: number,
    };