From f63001828fa68daf8f116767a55b355e73e59be3 Mon Sep 17 00:00:00 2001
From: chengyongru <chengyongru.ai@gmail.com>
Date: Wed, 19 Aug 2026 17:07:38 +0800
Subject: [PATCH] refactor(memory): guard empty summaries only on write

---
 nanobot/agent/memory.py                  |  6 +-----
 tests/agent/test_context_prompt_cache.py | 11 -----------
 2 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/nanobot/agent/memory.py b/nanobot/agent/memory.py
index f893424c6..a736335b5 100644
--- a/nanobot/agent/memory.py
+++ b/nanobot/agent/memory.py
@@ -431,11 +431,7 @@ class MemoryStore:
         unified_session: bool = False,
     ) -> list[dict[str, Any]]:
         """Return unprocessed history entries safe to inject into a turn prompt."""
-        entries = [
-            entry
-            for entry in self.read_unprocessed_history(since_cursor=since_cursor)
-            if str(entry.get("content", "")).strip() != "(nothing)"
-        ]
+        entries = self.read_unprocessed_history(since_cursor=since_cursor)
         if session_key is None:
             return entries
         if not unified_session:
diff --git a/tests/agent/test_context_prompt_cache.py b/tests/agent/test_context_prompt_cache.py
index a0d378d46..f9393f1c2 100644
--- a/tests/agent/test_context_prompt_cache.py
+++ b/tests/agent/test_context_prompt_cache.py
@@ -96,17 +96,6 @@ def test_unprocessed_history_injected_into_system_prompt(tmp_path) -> None:
     assert re.search(r"\[\d{4}-\d{2}-\d{2} \d{2}:\d{2}\]", prompt)
 
 
-def test_nothing_history_entry_is_not_injected(tmp_path) -> None:
-    workspace = _make_workspace(tmp_path)
-    builder = ContextBuilder(workspace)
-    builder.memory.append_history("(nothing)")
-
-    prompt = builder.build_system_prompt()
-
-    assert "# Recent History" not in prompt
-    assert "(nothing)" not in prompt
-
-
 def test_recent_history_injection_is_session_scoped(tmp_path) -> None:
     workspace = _make_workspace(tmp_path)
     builder = ContextBuilder(workspace)