macu-wallet/preload.js

const { contextBridge, ipcRenderer } = require('electron');

// Only these specific calls are exposed to the renderer (webpage) side.
// Nothing here touches the filesystem or private keys directly — every
// call is proxied through main.js, which is the only place that ever
// holds a decrypted mnemonic or private key.
contextBridge.exposeInMainWorld('macu', {
  hasKeystore: () => ipcRenderer.invoke('wallet:hasKeystore'),
  generateMnemonic: () => ipcRenderer.invoke('wallet:generateMnemonic'),
  createWallet: (mnemonic, password) => ipcRenderer.invoke('wallet:create', { mnemonic, password }),
  importWallet: (mnemonic, password) => ipcRenderer.invoke('wallet:import', { mnemonic, password }),
  unlock: (password) => ipcRenderer.invoke('wallet:unlock', { password }),
  lock: () => ipcRenderer.invoke('wallet:lock'),
  getBalances: () => ipcRenderer.invoke('wallet:balances'),
  sendEth: (to, amountEth) => ipcRenderer.invoke('wallet:sendEth', { to, amountEth }),
});