gemini-cli/packages/cli/src/ui/utils/updateCheck.ts

/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import updateNotifier from 'update-notifier';
import { readPackageUp } from 'read-package-up';
import process from 'node:process';

export async function checkForUpdates(): Promise<string | null> {
  // read-package-up looks for the closest package.json from cwd
  const pkgResult = await readPackageUp({ cwd: process.cwd() });
  if (!pkgResult) {
    return null;
  }

  const { packageJson } = pkgResult;
  const notifier = updateNotifier({
    pkg: {
      name: packageJson.name,
      version: packageJson.version,
    },
    // check every time
    updateCheckInterval: 0,
    // allow notifier to run in scripts
    shouldNotifyInNpmScript: true,
  });

  if (notifier.update) {
    return `Gemini CLI update available! ${notifier.update.current} → ${notifier.update.latest}\nRun npm install -g ${packageJson.name} to update`;
  }

  return null;
}