diff --git a/VERSION b/VERSION
index 561ad334..6aba2b24 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.1.6
+4.2.0
diff --git a/bin/ccs.js b/bin/ccs.js
index f189b5dc..d477c09b 100755
--- a/bin/ccs.js
+++ b/bin/ccs.js
@@ -181,6 +181,7 @@ function handleHelpCommand() {
   console.log(colored('Diagnostics:', 'cyan'));
   console.log(`  ${colored('ccs doctor', 'yellow')}                  Run health check and diagnostics`);
   console.log(`  ${colored('ccs sync', 'yellow')}                    Sync delegation commands and skills`);
+  console.log(`  ${colored('ccs update', 'yellow')}                  Update CCS to latest version`);
   console.log('');
 
   // Flags
@@ -285,6 +286,164 @@ async function handleSyncCommand() {
   process.exit(0);
 }
 
+async function handleUpdateCommand() {
+  const { checkForUpdates } = require('./utils/update-checker');
+  const { spawn } = require('child_process');
+
+  console.log('');
+  console.log(colored('Checking for updates...', 'cyan'));
+  console.log('');
+
+  // Detect installation method for proper update source
+  const isNpmInstall = process.argv[1].includes('node_modules');
+  const installMethod = isNpmInstall ? 'npm' : 'direct';
+
+  // Check for updates (force check)
+  const updateResult = await checkForUpdates(CCS_VERSION, true, installMethod);
+
+  if (updateResult.status === 'check_failed') {
+    console.log(colored(`[X] ${updateResult.message}`, 'red'));
+    console.log('');
+    console.log(colored('[i] Possible causes:', 'yellow'));
+    console.log('  • Network connection issues');
+    console.log('  • Firewall blocking requests');
+    console.log('  • GitHub/npm API temporarily unavailable');
+    console.log('');
+    console.log('Try again later or update manually:');
+    if (isNpmInstall) {
+      console.log(colored('  npm install -g @kaitranntt/ccs@latest', 'yellow'));
+    } else {
+      const isWindows = process.platform === 'win32';
+      if (isWindows) {
+        console.log(colored('  irm ccs.kaitran.ca/install | iex', 'yellow'));
+      } else {
+        console.log(colored('  curl -fsSL ccs.kaitran.ca/install | bash', 'yellow'));
+      }
+    }
+    console.log('');
+    process.exit(1);
+  }
+
+  if (updateResult.status === 'no_update') {
+    let message = `You are already on the latest version (${CCS_VERSION})`;
+
+    // Add context for why no update is shown
+    switch (updateResult.reason) {
+      case 'dismissed':
+        message = `Update dismissed. You are on version ${CCS_VERSION}`;
+        console.log(colored(`[i] ${message}`, 'yellow'));
+        break;
+      case 'cached':
+        message = `No updates available (cached result). You are on version ${CCS_VERSION}`;
+        console.log(colored(`[i] ${message}`, 'cyan'));
+        break;
+      default:
+        console.log(colored(`[OK] ${message}`, 'green'));
+    }
+    console.log('');
+    process.exit(0);
+  }
+
+  // Update available
+  console.log(colored(`[i] Update available: ${updateResult.current} → ${updateResult.latest}`, 'yellow'));
+  console.log('');
+
+  if (isNpmInstall) {
+    // npm installation - use npm update
+    console.log(colored('Updating via npm...', 'cyan'));
+    console.log('');
+
+    const child = spawn('npm', ['install', '-g', '@kaitranntt/ccs@latest'], {
+      stdio: 'inherit',
+      shell: true
+    });
+
+    child.on('exit', (code) => {
+      if (code === 0) {
+        console.log('');
+        console.log(colored('[OK] Update successful!', 'green'));
+        console.log('');
+        console.log(`Run ${colored('ccs --version', 'yellow')} to verify`);
+        console.log('');
+      } else {
+        console.log('');
+        console.log(colored('[X] Update failed', 'red'));
+        console.log('');
+        console.log('Try manually:');
+        console.log(colored('  npm install -g @kaitranntt/ccs@latest', 'yellow'));
+        console.log('');
+      }
+      process.exit(code || 0);
+    });
+
+    child.on('error', (err) => {
+      console.log('');
+      console.log(colored('[X] Failed to run npm update', 'red'));
+      console.log('');
+      console.log('Try manually:');
+      console.log(colored('  npm install -g @kaitranntt/ccs@latest', 'yellow'));
+      console.log('');
+      process.exit(1);
+    });
+  } else {
+    // Direct installation - re-run installer
+    console.log(colored('Updating via installer...', 'cyan'));
+    console.log('');
+
+    const isWindows = process.platform === 'win32';
+    let command, args;
+
+    if (isWindows) {
+      command = 'powershell.exe';
+      args = ['-Command', 'irm ccs.kaitran.ca/install | iex'];
+    } else {
+      command = 'bash';
+      args = ['-c', 'curl -fsSL ccs.kaitran.ca/install | bash'];
+    }
+
+    const child = spawn(command, args, {
+      stdio: 'inherit',
+      shell: true
+    });
+
+    child.on('exit', (code) => {
+      if (code === 0) {
+        console.log('');
+        console.log(colored('[OK] Update successful!', 'green'));
+        console.log('');
+        console.log(`Run ${colored('ccs --version', 'yellow')} to verify`);
+        console.log('');
+      } else {
+        console.log('');
+        console.log(colored('[X] Update failed', 'red'));
+        console.log('');
+        console.log('Try manually:');
+        if (isWindows) {
+          console.log(colored('  irm ccs.kaitran.ca/install | iex', 'yellow'));
+        } else {
+          console.log(colored('  curl -fsSL ccs.kaitran.ca/install | bash', 'yellow'));
+        }
+        console.log('');
+      }
+      process.exit(code || 0);
+    });
+
+    child.on('error', (err) => {
+      console.log('');
+      console.log(colored('[X] Failed to run installer', 'red'));
+      console.log('');
+      console.log('Try manually:');
+      if (isWindows) {
+        console.log(colored('  irm ccs.kaitran.ca/install | iex', 'yellow'));
+      } else {
+        console.log(colored('  curl -fsSL ccs.kaitran.ca/install | bash', 'yellow'));
+      }
+      console.log('');
+      process.exit(1);
+    });
+  }
+}
+
 // Smart profile detection
 function detectProfile(args) {
   if (args.length === 0 || args[0].startsWith('-')) {
@@ -528,6 +687,12 @@ async function main() {
     return;
   }
 
+  // Special case: update command (update CCS to latest version)
+  if (firstArg === 'update' || firstArg === '--update') {
+    await handleUpdateCommand();
+    return;
+  }
+
   // Special case: auth command (multi-account management)
   if (firstArg === 'auth') {
     const AuthCommands = require('./auth/auth-commands');
diff --git a/bin/utils/update-checker.js b/bin/utils/update-checker.js
new file mode 100644
index 00000000..278e88f7
--- /dev/null
+++ b/bin/utils/update-checker.js
@@ -0,0 +1,243 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+const https = require('https');
+const { colored } = require('./helpers');
+
+const UPDATE_CHECK_FILE = path.join(os.homedir(), '.ccs', 'update-check.json');
+const CHECK_INTERVAL = 24 * 60 * 60 * 1000; // 24 hours
+const GITHUB_API_URL = 'https://api.github.com/repos/kaitranntt/ccs/releases/latest';
+const NPM_REGISTRY_URL = 'https://registry.npmjs.org/@kaitranntt/ccs/latest';
+const REQUEST_TIMEOUT = 5000; // 5 seconds
+
+/**
+ * Compare semantic versions
+ * @param {string} v1 - First version (e.g., "4.1.6")
+ * @param {string} v2 - Second version
+ * @returns {number} - 1 if v1 > v2, -1 if v1 < v2, 0 if equal
+ */
+function compareVersions(v1, v2) {
+  const parts1 = v1.replace(/^v/, '').split('.').map(Number);
+  const parts2 = v2.replace(/^v/, '').split('.').map(Number);
+
+  for (let i = 0; i < 3; i++) {
+    const p1 = parts1[i] || 0;
+    const p2 = parts2[i] || 0;
+    if (p1 > p2) return 1;
+    if (p1 < p2) return -1;
+  }
+  return 0;
+}
+
+/**
+ * Fetch latest version from GitHub releases
+ * @returns {Promise<string|null>} - Latest version or null on error
+ */
+function fetchLatestVersionFromGitHub() {
+  return new Promise((resolve) => {
+    const req = https.get(GITHUB_API_URL, {
+      headers: { 'User-Agent': 'CCS-Update-Checker' },
+      timeout: REQUEST_TIMEOUT
+    }, (res) => {
+      let data = '';
+
+      res.on('data', (chunk) => {
+        data += chunk;
+      });
+
+      res.on('end', () => {
+        try {
+          if (res.statusCode !== 200) {
+            resolve(null);
+            return;
+          }
+
+          const release = JSON.parse(data);
+          const version = release.tag_name?.replace(/^v/, '') || null;
+          resolve(version);
+        } catch (err) {
+          resolve(null);
+        }
+      });
+    });
+
+    req.on('error', () => resolve(null));
+    req.on('timeout', () => {
+      req.destroy();
+      resolve(null);
+    });
+  });
+}
+
+/**
+ * Fetch latest version from npm registry
+ * @returns {Promise<string|null>} - Latest version or null on error
+ */
+function fetchLatestVersionFromNpm() {
+  return new Promise((resolve) => {
+    const req = https.get(NPM_REGISTRY_URL, {
+      headers: { 'User-Agent': 'CCS-Update-Checker' },
+      timeout: REQUEST_TIMEOUT
+    }, (res) => {
+      let data = '';
+
+      res.on('data', (chunk) => {
+        data += chunk;
+      });
+
+      res.on('end', () => {
+        try {
+          if (res.statusCode !== 200) {
+            resolve(null);
+            return;
+          }
+
+          const packageData = JSON.parse(data);
+          const version = packageData.version || null;
+          resolve(version);
+        } catch (err) {
+          resolve(null);
+        }
+      });
+    });
+
+    req.on('error', () => resolve(null));
+    req.on('timeout', () => {
+      req.destroy();
+      resolve(null);
+    });
+  });
+}
+
+/**
+ * Read update check cache
+ * @returns {Object} - Cache object
+ */
+function readCache() {
+  try {
+    if (!fs.existsSync(UPDATE_CHECK_FILE)) {
+      return { last_check: 0, latest_version: null, dismissed_version: null };
+    }
+
+    const data = fs.readFileSync(UPDATE_CHECK_FILE, 'utf8');
+    return JSON.parse(data);
+  } catch (err) {
+    return { last_check: 0, latest_version: null, dismissed_version: null };
+  }
+}
+
+/**
+ * Write update check cache
+ * @param {Object} cache - Cache object to write
+ */
+function writeCache(cache) {
+  try {
+    const ccsDir = path.join(os.homedir(), '.ccs');
+    if (!fs.existsSync(ccsDir)) {
+      fs.mkdirSync(ccsDir, { recursive: true, mode: 0o700 });
+    }
+
+    fs.writeFileSync(UPDATE_CHECK_FILE, JSON.stringify(cache, null, 2), 'utf8');
+  } catch (err) {
+    // Silently fail - not critical
+  }
+}
+
+/**
+ * Check for updates (async, non-blocking)
+ * @param {string} currentVersion - Current CCS version
+ * @param {boolean} force - Force check even if within interval
+ * @param {string} installMethod - Installation method ('npm' or 'direct')
+ * @returns {Promise<Object>} - Update result object with status and data
+ */
+async function checkForUpdates(currentVersion, force = false, installMethod = 'direct') {
+  const cache = readCache();
+  const now = Date.now();
+
+  // Check if we should check for updates
+  if (!force && (now - cache.last_check < CHECK_INTERVAL)) {
+    // Use cached result if available
+    if (cache.latest_version && compareVersions(cache.latest_version, currentVersion) > 0) {
+      // Don't show if user dismissed this version
+      if (cache.dismissed_version === cache.latest_version) {
+        return { status: 'no_update', reason: 'dismissed' };
+      }
+      return { status: 'update_available', latest: cache.latest_version, current: currentVersion };
+    }
+    return { status: 'no_update', reason: 'cached' };
+  }
+
+  // Fetch latest version from appropriate source
+  let latestVersion;
+  let fetchError = null;
+
+  if (installMethod === 'npm') {
+    latestVersion = await fetchLatestVersionFromNpm();
+    if (!latestVersion) fetchError = 'npm_registry_error';
+  } else {
+    latestVersion = await fetchLatestVersionFromGitHub();
+    if (!latestVersion) fetchError = 'github_api_error';
+  }
+
+  // Update cache
+  cache.last_check = now;
+  if (latestVersion) {
+    cache.latest_version = latestVersion;
+  }
+  writeCache(cache);
+
+  // Handle fetch errors
+  if (fetchError) {
+    return {
+      status: 'check_failed',
+      reason: fetchError,
+      message: `Failed to check for updates: ${fetchError.replace(/_/g, ' ')}`
+    };
+  }
+
+  // Check if update available
+  if (latestVersion && compareVersions(latestVersion, currentVersion) > 0) {
+    // Don't show if user dismissed this version
+    if (cache.dismissed_version === latestVersion) {
+      return { status: 'no_update', reason: 'dismissed' };
+    }
+    return { status: 'update_available', latest: latestVersion, current: currentVersion };
+  }
+
+  return { status: 'no_update', reason: 'latest' };
+}
+
+/**
+ * Show update notification
+ * @param {Object} updateInfo - Update information
+ */
+function showUpdateNotification(updateInfo) {
+  console.log('');
+  console.log(colored('═══════════════════════════════════════════════════════', 'cyan'));
+  console.log(colored(`  Update available: ${updateInfo.current} → ${updateInfo.latest}`, 'yellow'));
+  console.log(colored('═══════════════════════════════════════════════════════', 'cyan'));
+  console.log('');
+  console.log(`  Run ${colored('ccs update', 'yellow')} to update`);
+  console.log('');
+}
+
+/**
+ * Dismiss update notification for a specific version
+ * @param {string} version - Version to dismiss
+ */
+function dismissUpdate(version) {
+  const cache = readCache();
+  cache.dismissed_version = version;
+  writeCache(cache);
+}
+
+module.exports = {
+  compareVersions,
+  checkForUpdates,
+  showUpdateNotification,
+  dismissUpdate,
+  readCache,
+  writeCache
+};
diff --git a/installers/install.ps1 b/installers/install.ps1
index 30364486..bf904244 100644
--- a/installers/install.ps1
+++ b/installers/install.ps1
@@ -31,7 +31,7 @@ $InstallMethod = if ($ScriptDir -and ((Test-Path "$ScriptDir\lib\ccs.ps1") -or (
 # IMPORTANT: Update this version when releasing new versions!
 # This hardcoded version is used for standalone installations (irm | iex)
 # For git installations, VERSION file is read if available
-$CcsVersion = "4.1.6"
+$CcsVersion = "4.2.0"
 
 # Try to read VERSION file for git installations
 if ($ScriptDir) {
diff --git a/installers/install.sh b/installers/install.sh
index edc1a055..632b3e0d 100755
--- a/installers/install.sh
+++ b/installers/install.sh
@@ -32,7 +32,7 @@ fi
 # IMPORTANT: Update this version when releasing new versions!
 # This hardcoded version is used for standalone installations (curl | bash)
 # For git installations, VERSION file is read if available
-CCS_VERSION="4.1.6"
+CCS_VERSION="4.2.0"
 
 # Try to read VERSION file for git installations
 if [[ -f "$SCRIPT_DIR/VERSION" ]]; then
diff --git a/lib/ccs b/lib/ccs
index 9ad95b11..b0d1a22b 100755
--- a/lib/ccs
+++ b/lib/ccs
@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # Version (updated by scripts/bump-version.sh)
-CCS_VERSION="4.1.6"
+CCS_VERSION="4.2.0"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 readonly CONFIG_FILE="${CCS_CONFIG:-$HOME/.ccs/config.json}"
 readonly PROFILES_JSON="$HOME/.ccs/profiles.json"
@@ -199,6 +199,7 @@ show_help() {
   echo -e "${CYAN}Diagnostics:${RESET}"
   echo -e "  ${YELLOW}ccs doctor${RESET}                  Run health check and diagnostics"
   echo -e "  ${YELLOW}ccs sync${RESET}                    Sync delegation commands and skills"
+  echo -e "  ${YELLOW}ccs update${RESET}                  Update CCS to latest version"
   echo ""
 
   echo -e "${CYAN}Flags:${RESET}"
@@ -591,6 +592,124 @@ sync_run() {
   echo ""
 }
 
+# --- Update Command ---
+
+update_run() {
+  echo ""
+  echo -e "${CYAN}Checking for updates...${RESET}"
+  echo ""
+
+  # Detect installation method
+  local install_method="direct"
+  if command -v npm &>/dev/null && npm list -g @kaitranntt/ccs &>/dev/null 2>&1; then
+    install_method="npm"
+  fi
+
+  # Fetch latest version from appropriate source
+  local latest_version=""
+  if command -v curl &>/dev/null; then
+    if [[ "$install_method" == "npm" ]]; then
+      # Check npm registry for npm installations
+      latest_version=$(curl -fsSL https://registry.npmjs.org/@kaitranntt/ccs/latest 2>/dev/null | \
+        grep '"version"' | head -1 | sed -E 's/.*"version"[[:space:]]*:[[:space:]]*"([0-9.]+)".*/\1/')
+    else
+      # Check GitHub releases for direct installations
+      latest_version=$(curl -fsSL https://api.github.com/repos/kaitranntt/ccs/releases/latest 2>/dev/null | \
+        grep '"tag_name"' | sed -E 's/.*"v?([0-9.]+)".*/\1/')
+    fi
+  fi
+
+  if [[ -z "$latest_version" ]]; then
+    echo -e "${YELLOW}[!] Unable to check for updates${RESET}"
+    echo ""
+    echo "Try manually:"
+    if [[ "$install_method" == "npm" ]]; then
+      echo -e "  ${YELLOW}npm install -g @kaitranntt/ccs@latest${RESET}"
+    else
+      echo -e "  ${YELLOW}curl -fsSL ccs.kaitran.ca/install | bash${RESET}"
+    fi
+    echo ""
+    exit 1
+  fi
+
+  # Compare versions
+  if [[ "$latest_version" == "$CCS_VERSION" ]]; then
+    echo -e "${GREEN}[OK] You are already on the latest version (${CCS_VERSION})${RESET}"
+    echo ""
+    exit 0
+  fi
+
+  # Check if update available
+  local current_major=$(echo "$CCS_VERSION" | cut -d. -f1)
+  local current_minor=$(echo "$CCS_VERSION" | cut -d. -f2)
+  local current_patch=$(echo "$CCS_VERSION" | cut -d. -f3)
+
+  local latest_major=$(echo "$latest_version" | cut -d. -f1)
+  local latest_minor=$(echo "$latest_version" | cut -d. -f2)
+  local latest_patch=$(echo "$latest_version" | cut -d. -f3)
+
+  local is_newer=0
+  if [[ $latest_major -gt $current_major ]]; then
+    is_newer=1
+  elif [[ $latest_major -eq $current_major ]] && [[ $latest_minor -gt $current_minor ]]; then
+    is_newer=1
+  elif [[ $latest_major -eq $current_major ]] && [[ $latest_minor -eq $current_minor ]] && [[ $latest_patch -gt $current_patch ]]; then
+    is_newer=1
+  fi
+
+  if [[ $is_newer -eq 0 ]]; then
+    echo -e "${GREEN}[OK] You are on version ${CCS_VERSION} (latest is ${latest_version})${RESET}"
+    echo ""
+    exit 0
+  fi
+
+  echo -e "${YELLOW}[i] Update available: ${CCS_VERSION} → ${latest_version}${RESET}"
+  echo ""
+
+  # Perform update based on installation method
+  if [[ "$install_method" == "npm" ]]; then
+    echo -e "${CYAN}Updating via npm...${RESET}"
+    echo ""
+
+    if npm install -g @kaitranntt/ccs@latest; then
+      echo ""
+      echo -e "${GREEN}[OK] Update successful!${RESET}"
+      echo ""
+      echo -e "Run ${YELLOW}ccs --version${RESET} to verify"
+      echo ""
+      exit 0
+    else
+      echo ""
+      echo -e "${RED}[X] Update failed${RESET}"
+      echo ""
+      echo "Try manually:"
+      echo -e "  ${YELLOW}npm install -g @kaitranntt/ccs@latest${RESET}"
+      echo ""
+      exit 1
+    fi
+  else
+    echo -e "${CYAN}Updating via installer...${RESET}"
+    echo ""
+
+    if curl -fsSL ccs.kaitran.ca/install | bash; then
+      echo ""
+      echo -e "${GREEN}[OK] Update successful!${RESET}"
+      echo ""
+      echo -e "Run ${YELLOW}ccs --version${RESET} to verify"
+      echo ""
+      exit 0
+    else
+      echo ""
+      echo -e "${RED}[X] Update failed${RESET}"
+      echo ""
+      echo "Try manually:"
+      echo -e "  ${YELLOW}curl -fsSL ccs.kaitran.ca/install | bash${RESET}"
+      echo ""
+      exit 1
+    fi
+  fi
+}
+
 # --- Claude CLI Detection Logic ---
 
 detect_claude_cli() {
@@ -1669,6 +1788,12 @@ if [[ $# -gt 0 ]] && [[ "${1}" == "sync" || "${1}" == "--sync" ]]; then
   exit $?
 fi
 
+# Special case: update command
+if [[ $# -gt 0 ]] && [[ "${1}" == "update" || "${1}" == "--update" ]]; then
+  update_run
+  exit $?
+fi
+
 # Run auto-recovery before main logic
 auto_recover || {
   msg_error "Auto-recovery failed. Check permissions."
diff --git a/lib/ccs.ps1 b/lib/ccs.ps1
index dfaeb3d3..349097a7 100644
--- a/lib/ccs.ps1
+++ b/lib/ccs.ps1
@@ -12,7 +12,7 @@ param(
 $ErrorActionPreference = "Stop"
 
 # Version (updated by scripts/bump-version.sh)
-$CcsVersion = "4.1.6"
+$CcsVersion = "4.2.0"
 $ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 $ConfigFile = if ($env:CCS_CONFIG) { $env:CCS_CONFIG } else { "$env:USERPROFILE\.ccs\config.json" }
 $ProfilesJson = "$env:USERPROFILE\.ccs\profiles.json"
@@ -246,6 +246,7 @@ function Show-Help {
     Write-ColorLine "Diagnostics:" "Cyan"
     Write-ColorLine "  ccs doctor                  Run health check and diagnostics" "Yellow"
     Write-ColorLine "  ccs sync                    Sync delegation commands and skills" "Yellow"
+    Write-ColorLine "  ccs update                  Update CCS to latest version" "Yellow"
     Write-Host ""
 
     Write-ColorLine "Flags:" "Cyan"
@@ -1031,6 +1032,132 @@ function Sync-Run {
     Write-Host ""
 }
 
+# --- Update Command ---
+
+function Update-Run {
+    Write-Host ""
+    Write-Host "Checking for updates..." -ForegroundColor Cyan
+    Write-Host ""
+
+    # Detect installation method
+    $InstallMethod = "direct"
+    try {
+        $NpmList = npm list -g @kaitranntt/ccs 2>&1
+        if ($LASTEXITCODE -eq 0) {
+            $InstallMethod = "npm"
+        }
+    } catch {
+        # npm not available or not installed via npm
+    }
+
+    # Fetch latest version from appropriate source
+    $LatestVersion = ""
+    try {
+        if ($InstallMethod -eq "npm") {
+            # Check npm registry for npm installations
+            $Response = Invoke-RestMethod -Uri "https://registry.npmjs.org/@kaitranntt/ccs/latest" -TimeoutSec 5
+            $LatestVersion = $Response.version
+        } else {
+            # Check GitHub releases for direct installations
+            $Response = Invoke-RestMethod -Uri "https://api.github.com/repos/kaitranntt/ccs/releases/latest" -TimeoutSec 5
+            $LatestVersion = $Response.tag_name -replace '^v', ''
+        }
+    } catch {
+        Write-Host "[!] Unable to check for updates" -ForegroundColor Yellow
+        Write-Host ""
+        Write-Host "Try manually:"
+        if ($InstallMethod -eq "npm") {
+            Write-Host "  npm install -g @kaitranntt/ccs@latest" -ForegroundColor Yellow
+        } else {
+            Write-Host "  irm ccs.kaitran.ca/install | iex" -ForegroundColor Yellow
+        }
+        Write-Host ""
+        exit 1
+    }
+
+    # Compare versions
+    if ($LatestVersion -eq $CcsVersion) {
+        Write-Host "[OK] You are already on the latest version ($CcsVersion)" -ForegroundColor Green
+        Write-Host ""
+        exit 0
+    }
+
+    # Check if update available
+    $CurrentParts = $CcsVersion.Split('.')
+    $LatestParts = $LatestVersion.Split('.')
+
+    $IsNewer = $false
+    for ($i = 0; $i -lt 3; $i++) {
+        $Current = [int]$CurrentParts[$i]
+        $Latest = [int]$LatestParts[$i]
+
+        if ($Latest -gt $Current) {
+            $IsNewer = $true
+            break
+        } elseif ($Latest -lt $Current) {
+            break
+        }
+    }
+
+    if (-not $IsNewer) {
+        Write-Host "[OK] You are on version $CcsVersion (latest is $LatestVersion)" -ForegroundColor Green
+        Write-Host ""
+        exit 0
+    }
+
+    Write-Host "[i] Update available: $CcsVersion → $LatestVersion" -ForegroundColor Yellow
+    Write-Host ""
+
+    # Perform update based on installation method
+    if ($InstallMethod -eq "npm") {
+        Write-Host "Updating via npm..." -ForegroundColor Cyan
+        Write-Host ""
+
+        try {
+            npm install -g @kaitranntt/ccs@latest
+            if ($LASTEXITCODE -eq 0) {
+                Write-Host ""
+                Write-Host "[OK] Update successful!" -ForegroundColor Green
+                Write-Host ""
+                Write-Host "Run ccs --version to verify" -ForegroundColor Yellow
+                Write-Host ""
+                exit 0
+            } else {
+                throw "npm install failed"
+            }
+        } catch {
+            Write-Host ""
+            Write-Host "[X] Update failed" -ForegroundColor Red
+            Write-Host ""
+            Write-Host "Try manually:"
+            Write-Host "  npm install -g @kaitranntt/ccs@latest" -ForegroundColor Yellow
+            Write-Host ""
+            exit 1
+        }
+    } else {
+        Write-Host "Updating via installer..." -ForegroundColor Cyan
+        Write-Host ""
+
+        try {
+            irm ccs.kaitran.ca/install | iex
+            Write-Host ""
+            Write-Host "[OK] Update successful!" -ForegroundColor Green
+            Write-Host ""
+            Write-Host "Run ccs --version to verify" -ForegroundColor Yellow
+            Write-Host ""
+            exit 0
+        } catch {
+            Write-Host ""
+            Write-Host "[X] Update failed" -ForegroundColor Red
+            Write-Host ""
+            Write-Host "Try manually:"
+            Write-Host "  irm ccs.kaitran.ca/install | iex" -ForegroundColor Yellow
+            Write-Host ""
+            exit 1
+        }
+    }
+}
+
 # --- Auth Commands (Phase 3) ---
 
 function Show-AuthHelp {
@@ -1519,6 +1646,12 @@ if ($RemainingArgs.Count -gt 0 -and ($RemainingArgs[0] -eq "sync" -or $Remaining
     exit 0
 }
 
+# Special case: update command
+if ($RemainingArgs.Count -gt 0 -and ($RemainingArgs[0] -eq "update" -or $RemainingArgs[0] -eq "--update")) {
+    Update-Run
+    exit 0
+}
+
 # Run auto-recovery before main logic
 if (-not (Invoke-AutoRecovery)) {
     Write-ErrorMsg "Auto-recovery failed. Check permissions."
diff --git a/package.json b/package.json
index 05842b3c..3767b98b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@kaitranntt/ccs",
-  "version": "4.1.6",
+  "version": "4.2.0",
   "description": "Claude Code Switch - Instant profile switching between Claude Sonnet 4.5 and GLM 4.6",
   "keywords": [
     "cli",
diff --git a/scripts/completion/ccs.bash b/scripts/completion/ccs.bash
index 027791ae..63f07fb1 100644
--- a/scripts/completion/ccs.bash
+++ b/scripts/completion/ccs.bash
@@ -18,7 +18,7 @@ _ccs_completion() {
 
   # Top-level completion (first argument)
   if [[ ${COMP_CWORD} -eq 1 ]]; then
-    local commands="auth doctor sync"
+    local commands="auth doctor sync update"
     local flags="--help --version --shell-completion -h -v -sc"
     local profiles=""
 
diff --git a/scripts/completion/ccs.fish b/scripts/completion/ccs.fish
index aab2eb70..0688853c 100644
--- a/scripts/completion/ccs.fish
+++ b/scripts/completion/ccs.fish
@@ -73,21 +73,22 @@ complete -c ccs -s v -l version -d 'Show version information'
 complete -c ccs -s sc -l shell-completion -d 'Install shell completion'
 
 # Top-level commands (blue color for commands)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'auth' -d (set_color blue)'Manage multiple Claude accounts'(set_color normal)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'doctor' -d (set_color blue)'Run health check and diagnostics'(set_color normal)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'sync' -d (set_color blue)'Sync delegation commands and skills'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'auth' -d (set_color blue)'Manage multiple Claude accounts'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'doctor' -d (set_color blue)'Run health check and diagnostics'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'sync' -d (set_color blue)'Sync delegation commands and skills'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'update' -d (set_color blue)'Update CCS to latest version'(set_color normal)
 
 # Top-level known settings profiles (green color for model profiles)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'default' -d (set_color green)'Default Claude Sonnet 4.5'(set_color normal)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'glm' -d (set_color green)'GLM-4.6 (cost-optimized)'(set_color normal)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'glmt' -d (set_color green)'GLM-4.6 with thinking mode'(set_color normal)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a 'kimi' -d (set_color green)'Kimi for Coding (long-context)'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'default' -d (set_color green)'Default Claude Sonnet 4.5'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'glm' -d (set_color green)'GLM-4.6 (cost-optimized)'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'glmt' -d (set_color green)'GLM-4.6 with thinking mode'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a 'kimi' -d (set_color green)'Kimi for Coding (long-context)'(set_color normal)
 
 # Top-level custom settings profiles (dynamic, with generic description in green)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a '(__fish_ccs_get_custom_settings_profiles)' -d (set_color green)'Settings-based profile'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a '(__fish_ccs_get_custom_settings_profiles)' -d (set_color green)'Settings-based profile'(set_color normal)
 
 # Top-level account profiles (dynamic, yellow color for account profiles)
-complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync' -a '(__fish_ccs_get_account_profiles)' -d (set_color yellow)'Account profile'(set_color normal)
+complete -c ccs -n 'not __fish_seen_subcommand_from auth doctor sync update' -a '(__fish_ccs_get_account_profiles)' -d (set_color yellow)'Account profile'(set_color normal)
 
 # shell-completion subflags
 complete -c ccs -n '__fish_seen_argument -l shell-completion; or __fish_seen_argument -s sc' -l bash -d 'Install for bash'
diff --git a/scripts/completion/ccs.ps1 b/scripts/completion/ccs.ps1
index 1fec0d9f..9c5fada5 100644
--- a/scripts/completion/ccs.ps1
+++ b/scripts/completion/ccs.ps1
@@ -12,7 +12,7 @@
 Register-ArgumentCompleter -CommandName ccs -ScriptBlock {
     param($commandName, $wordToComplete, $commandAst, $fakeBoundParameters)
 
-    $commands = @('auth', 'doctor', 'sync', '--help', '--version', '--shell-completion', '-h', '-v', '-sc')
+    $commands = @('auth', 'doctor', 'sync', 'update', '--help', '--version', '--shell-completion', '-h', '-v', '-sc')
     $authCommands = @('create', 'list', 'show', 'remove', 'default', '--help', '-h')
     $shellCompletionFlags = @('--bash', '--zsh', '--fish', '--powershell')
     $listFlags = @('--verbose', '--json')
diff --git a/scripts/completion/ccs.zsh b/scripts/completion/ccs.zsh
index c31129a9..501ee4c7 100644
--- a/scripts/completion/ccs.zsh
+++ b/scripts/completion/ccs.zsh
@@ -16,7 +16,7 @@
 # Color codes: 0;34=blue, 0;32=green, 0;33=yellow, 2;37=dim white
 # Pattern format: =(#b)(group1)(group2)==color_for_group1=color_for_group2
 # The leading '=' means no color for whole match, then each '=' assigns to each group
-zstyle ':completion:*:*:ccs:*:commands' list-colors '=(#b)(auth|doctor|sync)([[:space:]]#--[[:space:]]#*)==0\;34=2\;37'
+zstyle ':completion:*:*:ccs:*:commands' list-colors '=(#b)(auth|doctor|sync|update)([[:space:]]#--[[:space:]]#*)==0\;34=2\;37'
 zstyle ':completion:*:*:ccs:*:model-profiles' list-colors '=(#b)(default|glm|glmt|kimi|[^[:space:]]##)([[:space:]]#--[[:space:]]#*)==0\;32=2\;37'
 zstyle ':completion:*:*:ccs:*:account-profiles' list-colors '=(#b)([^[:space:]]##)([[:space:]]#--[[:space:]]#*)==0\;33=2\;37'
 zstyle ':completion:*:*:ccs:*' group-name ''
@@ -35,6 +35,7 @@ _ccs() {
     'auth:Manage multiple Claude accounts'
     'doctor:Run health check and diagnostics'
     'sync:Sync delegation commands and skills'
+    'update:Update CCS to latest version'
   )
 
   # Define known settings profiles with descriptions (consistent padding)