diff --git a/api/commands.py b/api/commands.py
index 44f7b42825..7ebf5b4874 100644
--- a/api/commands.py
+++ b/api/commands.py
@@ -235,7 +235,7 @@ def migrate_annotation_vector_database():
                 if annotations:
                     for annotation in annotations:
                         document = Document(
-                            page_content=annotation.question,
+                            page_content=annotation.question_text,
                             metadata={"annotation_id": annotation.id, "app_id": app.id, "doc_id": annotation.id},
                         )
                         documents.append(document)
diff --git a/api/core/app/features/annotation_reply/annotation_reply.py b/api/core/app/features/annotation_reply/annotation_reply.py
index 79fbafe39e..3f9f3da9b2 100644
--- a/api/core/app/features/annotation_reply/annotation_reply.py
+++ b/api/core/app/features/annotation_reply/annotation_reply.py
@@ -75,7 +75,7 @@ class AnnotationReplyFeature:
                     AppAnnotationService.add_annotation_history(
                         annotation.id,
                         app_record.id,
-                        annotation.question,
+                        annotation.question_text,
                         annotation.content,
                         query,
                         user_id,
diff --git a/api/models/model.py b/api/models/model.py
index 88cb945b3f..6cfcc2859d 100644
--- a/api/models/model.py
+++ b/api/models/model.py
@@ -1419,15 +1419,20 @@ class MessageAnnotation(Base):
     app_id: Mapped[str] = mapped_column(StringUUID)
     conversation_id: Mapped[str | None] = mapped_column(StringUUID, sa.ForeignKey("conversations.id"))
     message_id: Mapped[str | None] = mapped_column(StringUUID)
-    question = mapped_column(LongText, nullable=True)
-    content = mapped_column(LongText, nullable=False)
+    question: Mapped[str | None] = mapped_column(LongText, nullable=True)
+    content: Mapped[str] = mapped_column(LongText, nullable=False)
     hit_count: Mapped[int] = mapped_column(sa.Integer, nullable=False, server_default=sa.text("0"))
-    account_id = mapped_column(StringUUID, nullable=False)
-    created_at = mapped_column(sa.DateTime, nullable=False, server_default=func.current_timestamp())
-    updated_at = mapped_column(
+    account_id: Mapped[str] = mapped_column(StringUUID, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(sa.DateTime, nullable=False, server_default=func.current_timestamp())
+    updated_at: Mapped[datetime] = mapped_column(
         sa.DateTime, nullable=False, server_default=func.current_timestamp(), onupdate=func.current_timestamp()
     )
 
+    @property
+    def question_text(self) -> str:
+        """Return a non-null question string, falling back to the answer content."""
+        return self.question or self.content
+
     @property
     def account(self):
         account = db.session.query(Account).where(Account.id == self.account_id).first()
diff --git a/api/services/annotation_service.py b/api/services/annotation_service.py
index d03cbddceb..7f44fe05a6 100644
--- a/api/services/annotation_service.py
+++ b/api/services/annotation_service.py
@@ -77,7 +77,7 @@ class AppAnnotationService:
         if annotation_setting:
             add_annotation_to_index_task.delay(
                 annotation.id,
-                annotation.question,
+                question,
                 current_tenant_id,
                 app_id,
                 annotation_setting.collection_binding_id,
@@ -253,7 +253,7 @@ class AppAnnotationService:
         if app_annotation_setting:
             update_annotation_to_index_task.delay(
                 annotation.id,
-                annotation.question,
+                annotation.question_text,
                 current_tenant_id,
                 app_id,
                 app_annotation_setting.collection_binding_id,
diff --git a/api/tasks/annotation/enable_annotation_reply_task.py b/api/tasks/annotation/enable_annotation_reply_task.py
index cdc07c77a8..be1de3cdd2 100644
--- a/api/tasks/annotation/enable_annotation_reply_task.py
+++ b/api/tasks/annotation/enable_annotation_reply_task.py
@@ -98,7 +98,7 @@ def enable_annotation_reply_task(
         if annotations:
             for annotation in annotations:
                 document = Document(
-                    page_content=annotation.question,
+                    page_content=annotation.question_text,
                     metadata={"annotation_id": annotation.id, "app_id": app_id, "doc_id": annotation.id},
                 )
                 documents.append(document)