diff --git a/install.ps1 b/install.ps1
index 58e54ad..e77780b 100644
--- a/install.ps1
+++ b/install.ps1
@@ -26,7 +26,61 @@ if (-not $Version) {
     }
 }
 
-Write-Host "Installing codeg-server $Version (windows/x64)..."
+$TargetVer = $Version -replace '^v', ''
+
+# ── Version detection — skip if already up to date ──
+
+$ExistingBin = Join-Path $InstallDir "codeg-server.exe"
+$CurrentVersion = ""
+$WasRunning = $false
+
+if (Test-Path $ExistingBin) {
+    # Run with timeout to handle old binaries that lack --version support
+    # (old binaries would start the full server and hang)
+    try {
+        $verProc = Start-Process -FilePath $ExistingBin -ArgumentList "--version" `
+            -NoNewWindow -PassThru -RedirectStandardOutput "$env:TEMP\codeg-ver.txt" `
+            -RedirectStandardError "$env:TEMP\codeg-ver-err.txt"
+        $exited = $verProc.WaitForExit(3000)
+        if (-not $exited) { $verProc.Kill() }
+        if (Test-Path "$env:TEMP\codeg-ver.txt") {
+            $CurrentVersion = (Get-Content "$env:TEMP\codeg-ver.txt" -ErrorAction SilentlyContinue | Select-Object -First 1).Trim()
+        }
+    } catch {
+        $CurrentVersion = ""
+    } finally {
+        Remove-Item "$env:TEMP\codeg-ver.txt" -Force -ErrorAction SilentlyContinue
+        Remove-Item "$env:TEMP\codeg-ver-err.txt" -Force -ErrorAction SilentlyContinue
+    }
+}
+
+if ($CurrentVersion -and ($CurrentVersion -eq $TargetVer)) {
+    Write-Host "codeg-server is already at version $TargetVer, nothing to do."
+    exit 0
+}
+
+if ($CurrentVersion) {
+    Write-Host "Upgrading codeg-server: $CurrentVersion -> $TargetVer..."
+} else {
+    Write-Host "Installing codeg-server $Version (windows/x64)..."
+}
+
+# ── Stop running service before upgrade ──
+
+$ServerProcesses = Get-Process -Name "codeg-server" -ErrorAction SilentlyContinue
+if ($ServerProcesses) {
+    Write-Host "Stopping running codeg-server process(es)..."
+    $WasRunning = $true
+    $ServerProcesses | Stop-Process -Force
+    Start-Sleep -Seconds 2
+    # Verify stopped
+    $StillRunning = Get-Process -Name "codeg-server" -ErrorAction SilentlyContinue
+    if ($StillRunning) {
+        $StillRunning | Stop-Process -Force
+        Start-Sleep -Seconds 1
+    }
+    Write-Host "codeg-server stopped."
+}
 
 # ── Download and extract ──
 
@@ -78,10 +132,26 @@ if ($UserPath -notlike "*$InstallDir*") {
 
 Remove-Item $TmpDir -Recurse -Force -ErrorAction SilentlyContinue
 
+# ── Restart service if it was running ──
+
+if ($WasRunning) {
+    Write-Host ""
+    Write-Host "Note: codeg-server was stopped for the upgrade."
+    Write-Host "Please restart it manually to ensure your environment variables (CODEG_PORT, CODEG_TOKEN, etc.) are preserved:"
+    Write-Host "  `$env:CODEG_STATIC_DIR=`"$WebDir`"; codeg-server"
+}
+
 # ── Done ──
 
+$InstalledVer = ""
+try {
+    $InstalledVer = (& (Join-Path $InstallDir "codeg-server.exe") --version 2>$null).Trim()
+} catch {}
+if (-not $InstalledVer) { $InstalledVer = $TargetVer }
+
 Write-Host ""
 Write-Host "codeg-server installed to $InstallDir\codeg-server.exe"
+Write-Host "Version: $InstalledVer"
 Write-Host ""
 Write-Host "Quick start:"
 Write-Host "  `$env:CODEG_STATIC_DIR=`"$WebDir`"; codeg-server"
diff --git a/install.sh b/install.sh
index 6dd6f45..f253e76 100755
--- a/install.sh
+++ b/install.sh
@@ -61,7 +61,63 @@ if [ -z "$VERSION" ]; then
   fi
 fi
 
-echo "Installing codeg-server ${VERSION} (${PLATFORM}/${ARCH_SUFFIX})..."
+# ── Version detection — skip if already up to date ──
+
+CURRENT_VERSION=""
+EXISTING_BIN="${INSTALL_DIR}/codeg-server"
+
+if [ -x "$EXISTING_BIN" ]; then
+  # Run with timeout to handle old binaries that lack --version support
+  # (old binaries would start the full server and hang)
+  VER_TMP=$(mktemp)
+  "$EXISTING_BIN" --version > "$VER_TMP" 2>/dev/null &
+  VER_PID=$!
+  ( sleep 3 && kill "$VER_PID" 2>/dev/null ) &
+  VER_GUARD=$!
+  wait "$VER_PID" 2>/dev/null || true
+  kill "$VER_GUARD" 2>/dev/null || true
+  wait "$VER_GUARD" 2>/dev/null || true
+  CURRENT_VERSION=$(head -1 "$VER_TMP" 2>/dev/null | tr -d '[:space:]')
+  rm -f "$VER_TMP"
+fi
+
+# Normalize: strip leading "v" for comparison
+TARGET_VER="${VERSION#v}"
+
+if [ -n "$CURRENT_VERSION" ] && [ "$CURRENT_VERSION" = "$TARGET_VER" ]; then
+  echo "codeg-server is already at version ${TARGET_VER}, nothing to do."
+  exit 0
+fi
+
+if [ -n "$CURRENT_VERSION" ]; then
+  echo "Upgrading codeg-server: ${CURRENT_VERSION} -> ${TARGET_VER}..."
+else
+  echo "Installing codeg-server ${VERSION} (${PLATFORM}/${ARCH_SUFFIX})..."
+fi
+
+# ── Stop running service before upgrade ──
+
+RESTARTED_PIDS=""
+if pgrep -x codeg-server >/dev/null 2>&1; then
+  echo "Stopping running codeg-server process(es)..."
+  RESTARTED_PIDS=$(pgrep -x codeg-server || true)
+  if kill $RESTARTED_PIDS 2>/dev/null; then
+    # Wait up to 10 seconds for graceful shutdown
+    for i in $(seq 1 10); do
+      if ! pgrep -x codeg-server >/dev/null 2>&1; then
+        break
+      fi
+      sleep 1
+    done
+    # Force kill if still running
+    if pgrep -x codeg-server >/dev/null 2>&1; then
+      echo "Force stopping codeg-server..."
+      kill -9 $RESTARTED_PIDS 2>/dev/null || true
+      sleep 1
+    fi
+  fi
+  echo "codeg-server stopped."
+fi
 
 # ── Download and extract ──
 
@@ -112,10 +168,21 @@ if [ -d "$WEB_SRC" ]; then
   fi
 fi
 
+# ── Restart service if it was running ──
+
+if [ -n "$RESTARTED_PIDS" ]; then
+  echo ""
+  echo "Note: codeg-server was stopped for the upgrade."
+  echo "Please restart it manually to ensure your environment variables (CODEG_PORT, CODEG_TOKEN, etc.) are preserved:"
+  echo "  CODEG_STATIC_DIR=${WEB_DIR} codeg-server"
+fi
+
 # ── Done ──
 
 echo ""
 echo "codeg-server installed to ${INSTALL_DIR}/codeg-server"
+INSTALLED_VER=$("${INSTALL_DIR}/codeg-server" --version 2>/dev/null || echo "${TARGET_VER}")
+echo "Version: ${INSTALLED_VER}"
 echo ""
 echo "Quick start:"
 echo "  CODEG_STATIC_DIR=${WEB_DIR} codeg-server"
diff --git a/src-tauri/src/bin/codeg_server.rs b/src-tauri/src/bin/codeg_server.rs
index b013876..cc01c75 100644
--- a/src-tauri/src/bin/codeg_server.rs
+++ b/src-tauri/src/bin/codeg_server.rs
@@ -9,6 +9,13 @@ use codeg_lib::web::{
 
 #[tokio::main]
 async fn main() {
+    // Support --version flag
+    let args: Vec<String> = std::env::args().collect();
+    if args.iter().any(|a| a == "--version" || a == "-V") {
+        println!("{}", env!("CARGO_PKG_VERSION"));
+        return;
+    }
+
     codeg_lib::process::ensure_user_npm_prefix_in_path();
 
     let port: u16 = std::env::var("CODEG_PORT")