diff --git a/src/components/routes/create-plan/CreatePlan.test.tsx b/src/components/routes/create-plan/CreatePlan.test.tsx
index 63ead223..3351247e 100644
--- a/src/components/routes/create-plan/CreatePlan.test.tsx
+++ b/src/components/routes/create-plan/CreatePlan.test.tsx
@@ -320,7 +320,7 @@ describe("CreatePlan Component", () => {
     const tagInput = screen.getByPlaceholderText("Add a tag");
     fireEvent.change(tagInput, { target: { value: "tag1" } });
     fireEvent.keyDown(tagInput, { key: "Enter", code: "Enter" });
-    expect(screen.getByText("tag1")).toBeInTheDocument();
+    expect(screen.getByText("Tag1")).toBeInTheDocument();
   });
 
   it("shows no image preview initially", () => {
diff --git a/src/components/routes/task/api/taskApi.ts b/src/components/routes/task/api/taskApi.ts
index 7c37ee27..c4f5ce69 100644
--- a/src/components/routes/task/api/taskApi.ts
+++ b/src/components/routes/task/api/taskApi.ts
@@ -46,7 +46,7 @@ export const createSubTasks = async (
     duration?: string;
     source_text_id?: string | null;
     pecha_segment_id?: string | null;
-    segment_id?: string | null;
+    segment_ids?: string[] | null;
   }[],
 ) => {
   const { data } = await axiosInstance.post(
@@ -72,7 +72,7 @@ export const updateSubTasks = async (
     duration?: string;
     source_text_id?: string | null;
     pecha_segment_id?: string | null;
-    segment_id?: string | null;
+    segment_ids?: string[] | null;
   }[],
 ) => {
   await axiosInstance.put(
diff --git a/src/components/routes/task/components/view/TaskForm.tsx b/src/components/routes/task/components/view/TaskForm.tsx
index d4ba6a5b..6ecb94d6 100644
--- a/src/components/routes/task/components/view/TaskForm.tsx
+++ b/src/components/routes/task/components/view/TaskForm.tsx
@@ -84,7 +84,7 @@ const TaskForm = ({
           ...(subTask.content_type === "SOURCE_REFERENCE" && {
             source_text_id: subTask.source_text_id || null,
             pecha_segment_id: subTask.pecha_segment_id || null,
-            segment_id: subTask.segment_id || null,
+            segment_ids: subTask.segment_ids || null,
           }),
         }));
         await createSubTasks(taskResponse.id, subTasksPayload);
@@ -117,7 +117,7 @@ const TaskForm = ({
         ...(subTask.content_type === "SOURCE_REFERENCE" && {
           source_text_id: subTask.source_text_id || null,
           pecha_segment_id: subTask.pecha_segment_id || null,
-          segment_id: subTask.segment_id || null,
+          segment_ids: subTask.segment_ids || null,
         }),
       }));
       await updateSubTasks(editingTask.id, subTasksPayload);
@@ -194,7 +194,7 @@ const TaskForm = ({
               content: data.content,
               source_text_id: data.source_text_id || null,
               pecha_segment_id: data.pecha_segment_id || null,
-              segment_id: data.segment_id || null,
+              segment_ids: data.segment_ids || null,
             };
           default:
             return {
@@ -212,7 +212,7 @@ const TaskForm = ({
     content: string;
     pecha_segment_id: string;
     text_id: string;
-    segment_id: string;
+    segment_ids: string[];
   }
 
   const handleAddSubTask = (content_type: any, sourceData?: SourceData) => {
@@ -256,7 +256,7 @@ const TaskForm = ({
           content: sourceData?.content || "",
           source_text_id: sourceData?.text_id || null,
           pecha_segment_id: sourceData?.pecha_segment_id || null,
-          segment_id: sourceData?.segment_id || null,
+          segment_ids: sourceData?.segment_ids || null,
         };
         break;
     }
diff --git a/src/components/ui/molecules/content-sub/ContentTypeSelector.tsx b/src/components/ui/molecules/content-sub/ContentTypeSelector.tsx
index 62d6e135..ed145a5a 100644
--- a/src/components/ui/molecules/content-sub/ContentTypeSelector.tsx
+++ b/src/components/ui/molecules/content-sub/ContentTypeSelector.tsx
@@ -10,7 +10,7 @@ interface SourceData {
   content: string;
   pecha_segment_id: string;
   text_id: string;
-  segment_id: string;
+  segment_ids: string[];
 }
 
 interface ContentTypeSelectorProps {
diff --git a/src/components/ui/molecules/subtask-card/SubTaskCard.tsx b/src/components/ui/molecules/subtask-card/SubTaskCard.tsx
index 92c2b449..f88e4749 100644
--- a/src/components/ui/molecules/subtask-card/SubTaskCard.tsx
+++ b/src/components/ui/molecules/subtask-card/SubTaskCard.tsx
@@ -46,7 +46,7 @@ interface SourceSubTask {
   display_order?: number;
   source_text_id?: string | null;
   pecha_segment_id?: string | null;
-  segment_id?: string | null;
+  segment_ids?: string[] | null;
 }
 export type SubTask =
   | VideoSubTask
diff --git a/src/components/ui/molecules/tag-input/TagInput.tsx b/src/components/ui/molecules/tag-input/TagInput.tsx
index ab6e5f5a..5c860010 100644
--- a/src/components/ui/molecules/tag-input/TagInput.tsx
+++ b/src/components/ui/molecules/tag-input/TagInput.tsx
@@ -13,7 +13,13 @@ const TagInput = ({ value = [], onChange }: TagInputProps) => {
   const handleKeyDown = (e: React.KeyboardEvent) => {
     if (e.key === "Enter" && inputValue.trim()) {
       e.preventDefault();
-      onChange?.([inputValue.trim(), ...value]);
+      const trimmed = inputValue.trim();
+      const normalizedTag =
+        trimmed.charAt(0).toUpperCase() + trimmed.slice(1).toLowerCase();
+
+      if (!value.includes(normalizedTag)) {
+        onChange?.([normalizedTag, ...value]);
+      }
       setInputValue("");
     }
   };
diff --git a/src/components/ui/molecules/webuddhist-source/SourceSelectorSheet.tsx b/src/components/ui/molecules/webuddhist-source/SourceSelectorSheet.tsx
index 5a0ef26c..d75d9248 100644
--- a/src/components/ui/molecules/webuddhist-source/SourceSelectorSheet.tsx
+++ b/src/components/ui/molecules/webuddhist-source/SourceSelectorSheet.tsx
@@ -13,7 +13,7 @@ interface SourceData {
   content: string;
   pecha_segment_id: string;
   text_id: string;
-  segment_id: string;
+  segment_ids: string[];
 }
 
 interface SourceSelectorSheetProps {
diff --git a/src/components/ui/molecules/webuddhist-source/sourceItem.tsx b/src/components/ui/molecules/webuddhist-source/sourceItem.tsx
index 9cc49b62..aafeb49a 100644
--- a/src/components/ui/molecules/webuddhist-source/sourceItem.tsx
+++ b/src/components/ui/molecules/webuddhist-source/sourceItem.tsx
@@ -19,7 +19,7 @@ const SourceItem = ({ source, onSegment }: any) => {
                 content: segment.content,
                 pecha_segment_id: segment.pecha_segment_id,
                 text_id: source.text.text_id,
-                segment_id: segment.segment_id,
+                segment_ids: [segment.segment_id],
               })
             }
           >