diff --git a/scripts/build-watch.sh b/scripts/build-watch.sh
index 0276843..174c468 100644
--- a/scripts/build-watch.sh
+++ b/scripts/build-watch.sh
@@ -1,12 +1,45 @@
+#!/bin/bash
+
+CACHE_FILE=".build-cache"
+
+needs_build() {
+    # If cache file doesn't exist, require build
+    if [ ! -f "$CACHE_FILE" ]; then
+        echo "Build required: first run"
+        return 0
+    fi
+
+    # Get all changed files from git
+    changed_files=$(git status --porcelain | awk '{print $NF}')
+
+    if [ -z "$changed_files" ]; then
+        return 1
+    fi
+
+    # Check if any changed file is a build source file and newer than cache
+    while IFS= read -r file; do
+        if [[ "$file" =~ \.(js|vue|less|css)$ ]] && [ -f "$file" ] && [ "$file" -nt "$CACHE_FILE" ]; then
+            echo "Build required: $file changed"
+            return 0
+        fi
+    done <<< "$changed_files"
+
+    return 1
+}
 
 upload() {
-    sh local-remote.sh --dry-run | grep -E "(\.less|\.js|\.vue|\.css)"
-
-    if [ $? -eq 0 ]; then
-        echo "Changes detected in build files - running build..."
-        npm run build && sh local-remote.sh
+    if needs_build; then
+        echo "Running build..."
+        if npm run build; then
+            # Update cache file timestamp
+            touch "$CACHE_FILE"
+            sh local-remote.sh
+        else
+            echo "Build failed, skipping upload"
+            exit 1
+        fi
     else
-        echo "No build files changed - uploading directly..."
+        echo "No build required - uploading directly..."
         sh local-remote.sh
     fi
 }
@@ -18,4 +51,4 @@ fi
 
 sh "remote-local.sh"
 
-watchexec --debounce 2s -w . 'sh watch-build.sh --upload'
+watchexec --debounce 1s -w . 'sh watch-build.sh --upload'