fix: rewriting a message is lost on reload due to a non-existent DB column (#1729)

routes/chat_routes.py

@@ -1266,7 +1266,7 @@ def setup_chat_routes(
                                 db_msg = (
                                     db.query(DBChatMessage)
                                     .filter(DBChatMessage.session_id == session_id, DBChatMessage.role == 'assistant')
-                                    .order_by(DBChatMessage.created_at.desc())
+                                    .order_by(DBChatMessage.timestamp.desc())
                                     .first()
                                 )
                                 if db_msg:

tests/test_rewrite_persist_column.py

@@ -0,0 +1,66 @@
+"""Rewriting the last assistant message must persist to the DB.
+
+The /api/rewrite persistence path ordered by DBChatMessage.created_at, but
+the ChatMessage model has no created_at column (only timestamp). Building
+that query raised AttributeError, which the surrounding except swallowed,
+and since session_manager.save_sessions() is a no-op this DB UPDATE was the
+only persistence path. The rewrite was shown live but silently lost on
+reload.
+"""
+import tempfile
+import uuid
+from datetime import datetime, timedelta
+
+import pytest
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import NullPool
+
+import core.database as cdb
+from core.database import ChatMessage as DBChatMessage, Session as DbSession
+
+
+def test_chatmessage_has_timestamp_not_created_at():
+    # The old code referenced .created_at, which does not exist -> AttributeError.
+    assert hasattr(DBChatMessage, "timestamp")
+    assert not hasattr(DBChatMessage, "created_at")
+
+
+def test_rewrite_query_selects_and_updates_latest_assistant_message():
+    tmp = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
+    engine = create_engine(f"sqlite:///{tmp.name}", connect_args={"check_same_thread": False}, poolclass=NullPool)
+    cdb.Base.metadata.create_all(engine)
+    TS = sessionmaker(bind=engine, autoflush=False, autocommit=False)
+
+    sid = "s-" + uuid.uuid4().hex[:8]
+    base = datetime(2026, 6, 3, 12, 0, 0)
+    db = TS()
+    try:
+        db.add(DbSession(id=sid, owner="alice", name="c", model="m", archived=False))
+        db.add(DBChatMessage(id="m1", session_id=sid, role="assistant", content="old first", timestamp=base))
+        db.add(DBChatMessage(id="m2", session_id=sid, role="assistant", content="old latest", timestamp=base + timedelta(minutes=1)))
+        db.commit()
+    finally:
+        db.close()
+
+    # Exactly the query the rewrite path runs (with the fixed column).
+    db = TS()
+    try:
+        db_msg = (
+            db.query(DBChatMessage)
+            .filter(DBChatMessage.session_id == sid, DBChatMessage.role == "assistant")
+            .order_by(DBChatMessage.timestamp.desc())
+            .first()
+        )
+        assert db_msg is not None and db_msg.id == "m2"
+        db_msg.content = "rewritten"
+        db.commit()
+    finally:
+        db.close()
+
+    db = TS()
+    try:
+        latest = db.query(DBChatMessage).filter(DBChatMessage.id == "m2").first()
+        assert latest.content == "rewritten"
+    finally:
+        db.close()