diff --git a/services/rag-api/services/retriever.py b/services/rag-api/services/retriever.py
index 26657bf..284190a 100644
--- a/services/rag-api/services/retriever.py
+++ b/services/rag-api/services/retriever.py
@@ -30,8 +30,11 @@ async def hybrid_search(
     """
     start = time.monotonic()
 
+    # Convert embedding list to pgvector string format
+    embedding_str = '[' + ','.join(str(x) for x in embedding) + ']'
+
     tag_filter = ''
-    params: list = [embedding, query, limit * 2, threshold]
+    params: list = [embedding_str, query, limit * 2, threshold]
 
     if tags:
         tag_filter = 'AND d.tags && $5'