Add auto-update checker

Checks npm registry for newer versions and prompts user to update.
Caches check results for 24 hours to avoid spamming.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gricha

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@gricha/perry",
-  "version": "0.1.4",
+  "version": "0.1.5",
   "description": "Self-contained CLI for spinning up Docker-in-Docker development environments with SSH and proxy helpers.",
   "type": "module",
   "bin": {

src/index.ts

@@ -17,6 +17,7 @@ import {
 import { loadAgentConfig, getConfigDir, ensureConfigDir } from './config/loader';
 import { buildImage } from './docker';
 import { DEFAULT_AGENT_PORT, WORKSPACE_IMAGE_LOCAL } from './shared/constants';
+import { checkForUpdates } from './update-checker';
 
 const program = new Command();
 
@@ -513,4 +514,6 @@ function formatUptime(seconds: number): string {
   return parts.join(' ');
 }
 
+checkForUpdates(pkg.version);
+
 program.parse();

src/update-checker.ts

@@ -0,0 +1,93 @@
+import { homedir } from 'os';
+import { join } from 'path';
+import { mkdir, readFile, writeFile } from 'fs/promises';
+
+const PACKAGE_NAME = '@gricha/perry';
+const CHECK_INTERVAL_MS = 24 * 60 * 60 * 1000; // 24 hours
+
+interface UpdateCache {
+  lastCheck: number;
+  latestVersion: string | null;
+}
+
+async function getCacheDir(): Promise<string> {
+  const dir = join(homedir(), '.config', 'perry');
+  await mkdir(dir, { recursive: true });
+  return dir;
+}
+
+async function readCache(): Promise<UpdateCache | null> {
+  try {
+    const cacheFile = join(await getCacheDir(), 'update-cache.json');
+    const content = await readFile(cacheFile, 'utf-8');
+    return JSON.parse(content);
+  } catch {
+    return null;
+  }
+}
+
+async function writeCache(cache: UpdateCache): Promise<void> {
+  try {
+    const cacheFile = join(await getCacheDir(), 'update-cache.json');
+    await writeFile(cacheFile, JSON.stringify(cache));
+  } catch {
+    // Ignore cache write errors
+  }
+}
+
+async function fetchLatestVersion(): Promise<string | null> {
+  try {
+    const response = await fetch(`https://registry.npmjs.org/${PACKAGE_NAME}/latest`, {
+      signal: AbortSignal.timeout(3000),
+    });
+    if (!response.ok) return null;
+    const data = (await response.json()) as { version?: string };
+    return data.version || null;
+  } catch {
+    return null;
+  }
+}
+
+function compareVersions(current: string, latest: string): number {
+  const currentParts = current.split('.').map(Number);
+  const latestParts = latest.split('.').map(Number);
+
+  for (let i = 0; i < Math.max(currentParts.length, latestParts.length); i++) {
+    const c = currentParts[i] || 0;
+    const l = latestParts[i] || 0;
+    if (l > c) return 1;
+    if (l < c) return -1;
+  }
+  return 0;
+}
+
+export async function checkForUpdates(currentVersion: string): Promise<void> {
+  try {
+    const cache = await readCache();
+    const now = Date.now();
+
+    let latestVersion: string | null = null;
+
+    if (cache && now - cache.lastCheck < CHECK_INTERVAL_MS) {
+      latestVersion = cache.latestVersion;
+    } else {
+      latestVersion = await fetchLatestVersion();
+      await writeCache({ lastCheck: now, latestVersion });
+    }
+
+    if (latestVersion && compareVersions(currentVersion, latestVersion) > 0) {
+      console.log('');
+      console.log(`\x1b[33m╭─────────────────────────────────────────────────────────╮\x1b[0m`);
+      console.log(
+        `\x1b[33m│\x1b[0m  Update available: \x1b[90m${currentVersion}\x1b[0m → \x1b[32m${latestVersion}\x1b[0m                     \x1b[33m│\x1b[0m`
+      );
+      console.log(
+        `\x1b[33m│\x1b[0m  Run \x1b[36mnpm install -g ${PACKAGE_NAME}\x1b[0m to update   \x1b[33m│\x1b[0m`
+      );
+      console.log(`\x1b[33m╰─────────────────────────────────────────────────────────╯\x1b[0m`);
+      console.log('');
+    }
+  } catch {
+    // Silently ignore update check errors
+  }
+}