diff --git a/hermes_state_maintenance.py b/hermes_state_maintenance.py
index 680a2d3fd6..31132f98fe 100644
--- a/hermes_state_maintenance.py
+++ b/hermes_state_maintenance.py
@@ -247,7 +247,9 @@ class SessionMaintenanceMixin:
         latest message / ``started_at``); may archive unended sessions.  ``archived = 0`` makes
         repeats no-ops; only lineage tips (``end_reason <> 'compression'``) are candidates — a
         stale tip archives its chain via :meth:`set_session_archived`, so an old compressed-away
-        root with a recent continuation is never matched."""
+        root with a recent continuation is never matched.  The hidden canonical Bot Chat (same
+        predicate as :meth:`set_session_pinned`) is exempt: only a deliberate archive may retire
+        it, since archiving releases its registry title to the next Bot open."""
         if idle_days is None or idle_days < 0:
             return 0
         cutoff = time.time() - float(idle_days) * 86400.0
@@ -258,9 +260,10 @@ class SessionMaintenanceMixin:
             WHERE s.archived = 0
               AND COALESCE(s.end_reason, '') <> 'compression'
               {pin_clause}
+              AND NOT (COALESCE(s.hidden, 0) <> 0 AND COALESCE(s.title, '') = ?)
               AND {_sql_session_last_active("s")} < ?
             ORDER BY s.started_at ASC
-            """, (cutoff,))
+            """, (self.CANONICAL_BOT_CHAT_TITLE, cutoff))
         for row in rows:
             self.set_session_archived(row[0], True)
         return len(rows)
diff --git a/tests/hermes_state/test_canonical_title_guard.py b/tests/hermes_state/test_canonical_title_guard.py
index de75a5043e..a7a6e060f6 100644
--- a/tests/hermes_state/test_canonical_title_guard.py
+++ b/tests/hermes_state/test_canonical_title_guard.py
@@ -78,6 +78,22 @@ def test_deliberately_archived_canonical_chat_releases_name_for_replacement(db):
     assert row and row["id"] == "replacement"
 
 
+def test_auto_archive_sweep_skips_the_canonical_chat(db):
+    """Only a deliberate archive may retire a Bot Chat; the idle sweep must not
+    (it would strand an unrecoverable, soon-to-be-untitled row)."""
+    import time
+
+    forever = _make_canonical(db)
+    db.create_session("ordinary", source="desktop")
+    stale = time.time() - 10 * 86400
+    db._write_sql("UPDATE sessions SET started_at = ?, last_activity_at = ?", (stale, stale))
+
+    assert db.archive_stale_sessions(3) == 1
+    assert db.get_session("ordinary")["archived"]
+    assert not db.get_session(forever)["archived"]
+    assert db.get_session(forever)["title"] == SessionDB.CANONICAL_BOT_CHAT_TITLE
+
+
 def test_auto_titler_still_cannot_touch_the_canonical_row(db):
     # Pre-existing provenance contract, re-pinned here: user-authority title
     # outranks derived/llm, so the turn-start auto-titler can never displace
diff --git a/website/docs/user-guide/bot-mode.md b/website/docs/user-guide/bot-mode.md
index 70f1cb3aad..4c13fec82e 100644
--- a/website/docs/user-guide/bot-mode.md
+++ b/website/docs/user-guide/bot-mode.md
@@ -25,7 +25,7 @@ The roster shows one row per agent profile: avatar, latest-message preview, and
 :::note The canonical Bot Chat is a forever-chat
 Typing `/new` (or `/reset`) inside a Bot's canonical chat would fork the relationship into a scratch session — the one thing Bot Mode promises never happens. The composer reroutes it to `/compact` instead: fresh working context, same conversation. Regular sessions on the same profile keep full `/new` freedom.
 
-Archiving a Bot Chat from the sidebar retires it: the next click on the Bot starts a fresh conversation that becomes the new canonical Bot Chat, and the archived one keeps its history (untitled) in the archive.
+Archiving a Bot Chat from the sidebar retires it: the next click on the Bot starts a fresh conversation that becomes the new canonical Bot Chat. The retired chat stays archived and hidden — its history is preserved in the database, but it is no longer reachable from the Bot or the archive view. The automatic idle-archive sweep (`sessions.auto_archive`) never retires a Bot Chat; only an explicit archive does.
 :::
 
 ### Organize bots into sections