solana/web3.js/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,
};