diff --git a/apps/api/src/repositories/knowledge_repository.py b/apps/api/src/repositories/knowledge_repository.py
index 9cfda483..808403a3 100644
--- a/apps/api/src/repositories/knowledge_repository.py
+++ b/apps/api/src/repositories/knowledge_repository.py
@@ -190,7 +190,7 @@ class KnowledgeDBRepository:
             count_query = count_query.where(KnowledgeEntryRecord.status == status)
         if tags:
             for tag in tags:
-                tag_filter = KnowledgeEntryRecord.tags.op('@>')(f'["{tag}"]')
+                tag_filter = _json_string_array_has_tag(tag)
                 query = query.where(tag_filter)
                 count_query = count_query.where(tag_filter)
         if q:
@@ -347,3 +347,18 @@ class KnowledgeDBRepository:
             created_at=record.created_at,
             updated_at=record.updated_at,
         )
+
+
+def _json_string_array_has_tag(tag: str):
+    """建立 JSON/JSONB 皆相容的 tag filter。
+
+    production 的 knowledge_entries.tags 目前是 JSON 欄位，不支援 json @> text。
+    這裡改用帶引號的字串比對，避免把 tag 片段誤判成完整 tag。
+    """
+    escaped = (
+        tag
+        .replace("\\", "\\\\")
+        .replace("%", "\\%")
+        .replace("_", "\\_")
+    )
+    return KnowledgeEntryRecord.tags.cast(String).ilike(f'%"{escaped}"%', escape="\\")
diff --git a/apps/api/tests/test_hermes_kb_growth_worker.py b/apps/api/tests/test_hermes_kb_growth_worker.py
index 4652d3ca..d43d0fac 100644
--- a/apps/api/tests/test_hermes_kb_growth_worker.py
+++ b/apps/api/tests/test_hermes_kb_growth_worker.py
@@ -74,6 +74,16 @@ def test_review_context_keeps_succeeded_at_owner_review_stage():
     assert updated["worker_result"]["status"] == "draft_created"
 
 
+def test_knowledge_tag_filter_is_json_column_compatible():
+    """knowledge_entries.tags 是 JSON 欄位時不可使用 json @> text。"""
+    from src.repositories.knowledge_repository import _json_string_array_has_tag
+
+    compiled = str(_json_string_array_has_tag("dispatch:abc-123"))
+
+    assert "CAST(knowledge_entries.tags AS VARCHAR)" in compiled
+    assert "@>" not in compiled
+
+
 @pytest.mark.asyncio
 async def test_run_once_advances_pending_dispatch_to_review_draft():
     """pending dispatch 應推進到 succeeded + waiting_owner_review read model。"""