diff --git a/package.json b/package.json
index bc37a5d8..efa74e5b 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,7 @@
   ],
   "preferGlobal": true,
   "scripts": {
+    "preinstall": "node scripts/preinstall.js",
     "build": "tsc && node scripts/add-shebang.js",
     "build:watch": "tsc --watch",
     "build:server": "tsc && node scripts/add-shebang.js",
diff --git a/scripts/preinstall.js b/scripts/preinstall.js
new file mode 100644
index 00000000..06e19182
--- /dev/null
+++ b/scripts/preinstall.js
@@ -0,0 +1,59 @@
+#!/usr/bin/env node
+'use strict';
+
+/**
+ * CCS Preinstall Script
+ * Installs dependencies in ui/ folder before main install
+ *
+ * Runs when: bun install, npm install, yarn install
+ * Skips when: CI environment or global install (npm -g)
+ */
+
+const { execSync } = require('child_process');
+const fs = require('fs');
+const path = require('path');
+
+// Skip in CI environments or global installs
+if (process.env.CI || process.env.npm_config_global === 'true') {
+  process.exit(0);
+}
+
+const uiDir = path.join(__dirname, '..', 'ui');
+const uiPackageJson = path.join(uiDir, 'package.json');
+
+// Skip if ui/ folder or package.json doesn't exist
+if (!fs.existsSync(uiPackageJson)) {
+  process.exit(0);
+}
+
+// Detect package manager (prefer bun > npm)
+function getPackageManager() {
+  // Check if running via bun
+  if (process.env.npm_execpath?.includes('bun') || process.env._?.includes('bun')) {
+    return 'bun';
+  }
+  // Check if bun is available
+  try {
+    execSync('bun --version', { stdio: 'ignore' });
+    return 'bun';
+  } catch {
+    return 'npm';
+  }
+}
+
+const pm = getPackageManager();
+
+console.log(`[i] Installing ui/ dependencies with ${pm}...`);
+
+try {
+  execSync(`${pm} install`, {
+    cwd: uiDir,
+    stdio: 'inherit',
+    env: { ...process.env, npm_config_global: undefined }
+  });
+  console.log('[OK] ui/ dependencies installed');
+} catch (err) {
+  console.error('[!] Failed to install ui/ dependencies:', err.message);
+  console.error('    You can manually install: cd ui && bun install');
+  // Don't fail the main install - ui is optional for CLI usage
+}