Electron

Overview

Electron is a framework for building cross-platform desktop applications using web technologies. It combines a Node.js main process for system access and window management with Chromium renderer processes for the UI, communicating via IPC with context isolation and preload scripts for security.

Instructions

• When starting a project, install electron as a dev dependency (npm install --save-dev electron), or scaffold with Electron Forge (npm init electron-app@latest my-app). Point main in package.json at the main-process file and run with electron .. Current stable line: Electron 44 (checked 44.5.1).
• When setting up the architecture, create a main process for window management and system APIs, renderer processes for UI, and a preload script that exposes a small, named API with contextBridge.exposeInMainWorld(). Never expose ipcRenderer itself.
• When implementing IPC, use ipcMain.handle() / ipcRenderer.invoke() for request-response, and webContents.send() for main-to-renderer push. Validate arguments and the sender (event.senderFrame.origin, not the URL) inside every handler.
• When accessing native APIs, use dialogs, file system, clipboard, notifications and shell in the main process and reach them from the renderer only through the preload bridge.
• When configuring security, rely on the defaults (contextIsolation: true since Electron 12, nodeIntegration: false, sandbox: true for renderers) and do not turn them off. Add a Content Security Policy, deny unexpected navigation with will-navigate and webContents.setWindowOpenHandler(), never pass untrusted URLs to shell.openExternal, and flip unused fuses (runAsNode, nodeCliInspect) with @electron/fuses.
• When packaging, use Electron Forge (makers: Squirrel.Windows or WiX/MSI, DMG/ZIP, deb/rpm/AppImage via community makers) or electron-builder; sign Windows builds and sign plus notarize macOS builds.
• When implementing auto-updates, use the built-in autoUpdater (Squirrel) with a static storage URL or update.electronjs.org for public GitHub repos, or electron-updater from electron-builder, which supports GitHub Releases or a generic server, differential downloads, and a stagingPercentage field in the release metadata for staged rollouts. autoUpdater does not work on Linux; updates there come through the package manager or AppImage updaters.
• When the renderer crashes, handle webContents.on("render-process-gone", ...) and app.on("child-process-gone", ...), and reload or show an error window.

Minimal secure skeleton

// main.js
const { app, BrowserWindow, ipcMain, dialog } = require("electron");
const path = require("node:path");

function createWindow() {
  const win = new BrowserWindow({
    width: 1100, height: 720,
    webPreferences: { preload: path.join(__dirname, "preload.js") }, // defaults stay secure
  });
  win.webContents.setWindowOpenHandler(() => ({ action: "deny" }));
  win.loadFile("index.html");
}

ipcMain.handle("dialog:openFile", async (event) => {
  if (event.senderFrame?.origin !== "file://") return null; // only our own page
  const { canceled, filePaths } = await dialog.showOpenDialog({ properties: ["openFile"] });
  return canceled ? null : filePaths[0];
});

app.whenReady().then(createWindow);
app.on("window-all-closed", () => { if (process.platform !== "darwin") app.quit(); });

{
  "name": "file-manager",
  "version": "1.0.0",
  "main": "main.js",
  "scripts": { "start": "electron ." },
  "devDependencies": { "electron": "^44.5.1" }
}

// preload.js
const { contextBridge, ipcRenderer } = require("electron");
contextBridge.exposeInMainWorld("files", { openFile: () => ipcRenderer.invoke("dialog:openFile") });

Examples

Example 1: Build a file manager with native dialogs

User request: "Create an Electron app that browses and manages files with native dialogs"

Actions:

1. Set up main process with BrowserWindow and preload script exposing file system commands
2. Implement IPC handlers for dialog.showOpenDialog(), dialog.showSaveDialog(), and file operations
3. Build a React-based renderer UI for browsing directories and previewing files
4. Add context menus and keyboard shortcuts for file operations
5. Run npx electron . and confirm that window.files.openFile() in DevTools returns a path while require is undefined in the renderer

Output: A cross-platform file manager with native OS dialogs and secure IPC-based file access.

Example 2: Add auto-updates with staged rollout

User request: "Set up auto-updates for my Electron app using GitHub Releases"

Actions:

1. Configure electron-builder with publish settings pointing to GitHub Releases
2. Add electron-updater in the main process with update check on startup
3. Implement update UI in the renderer showing download progress and restart prompt
4. Set stagingPercentage (for example 10) in the published latest.yml to update a share of users first, and raise it as the release proves stable

Output: An Electron app that automatically checks for updates, downloads them in the background, and prompts the user to restart.

Guidelines

• Always use context isolation and preload scripts; never enable nodeIntegration in the renderer or disable sandbox.
• Validate all IPC message data and the sender frame in the main process since the renderer is untrusted like a browser.
• Use ipcMain.handle() / ipcRenderer.invoke() for async operations over the older send/on pattern.
• Minimize main process work to keep it responsive for window management and IPC routing.
• Set CSP headers on all windows: default-src 'self'; script-src 'self'.
• Test on all target platforms since Windows, macOS, and Linux behave differently for menus, shortcuts, and file paths.
• Handle the render-process-gone event on webContents and monitor memory with process.getProcessMemoryInfo() or app.getAppMetrics().
• Keep Electron current: each major ships a new Chromium, and old majors stop receiving security fixes.
• Never load remote content in a window that has a privileged preload; prefer custom protocols over file:// for app content.