packages/web/src/pages/RecipeDetail.tsx

@@ -127,9 +127,11 @@ function RecipeDetail() {
     const trimmedTag = tagInput.trim();
 
     // Convert existing tags to string array (handle both string and object formats)
-    const existingTagNames = (recipe.tags || []).map(tagItem =>
+    const existingTagNames = (recipe.tags || [])
+      .map(tagItem =>
         typeof tagItem === 'string' ? tagItem : tagItem.tag?.name || tagItem.name
-    );
+      )
+      .filter((tag): tag is string => tag !== undefined);
 
     // Check if tag already exists on recipe
     if (existingTagNames.includes(trimmedTag)) {
@@ -168,9 +170,11 @@ function RecipeDetail() {
     try {
       setSavingTags(true);
       // Convert existing tags to string array and filter out the removed tag
-      const existingTagNames = (recipe.tags || []).map(tagItem =>
+      const existingTagNames = (recipe.tags || [])
+        .map(tagItem =>
           typeof tagItem === 'string' ? tagItem : tagItem.tag?.name || tagItem.name
-      );
+        )
+        .filter((tag): tag is string => tag !== undefined);
       const updatedTags = existingTagNames.filter(tag => tag !== tagToRemove);
       await recipesApi.update(id, { tags: updatedTags });
 
@@ -265,6 +269,7 @@ function RecipeDetail() {
               recipe.tags.map(tagItem => {
                 // Handle both string tags and object tags from API
                 const tagName = typeof tagItem === 'string' ? tagItem : tagItem.tag?.name || tagItem.name;
+                if (!tagName) return null; // Skip if tagName is undefined
                 return (
                   <span key={tagName} className="tag-chip-inline">
                     {tagName}