fix(memory): remove idle archive request fallback

nanobot/agent/memory.py

@@ -1064,7 +1064,11 @@ class Consolidator:
             logger.warning("Consolidation provider returned tool calls, raw-dumping to history")
             self.store.raw_archive(fallback_messages, session_key=session_key)
             return None
-        summary = response.content or "[no summary]"
+        summary = response.content
+        if not summary or not summary.strip():
+            logger.warning("Consolidation provider returned no summary, raw-dumping to history")
+            self.store.raw_archive(fallback_messages, session_key=session_key)
+            return None
         self.store.append_history(
             summary,
             max_chars=_ARCHIVE_SUMMARY_MAX_CHARS,
@@ -1154,19 +1158,21 @@ class Consolidator:
             runtime=runtime,
         )
         if request_messages is None:
-            return await self.archive(
+            logger.debug(
-                messages,
+                "Idle consolidation cannot replay the full tail for {}; raw-dumping",
-                runtime=runtime,
+                session.key,
-                session_key=session.key,
             )
-        tools = self._get_tool_definitions()
+            self.store.raw_archive(messages, session_key=session.key)
+            return None
         budget = self._input_token_budget(runtime)
         if budget <= 0:
-            return await self.archive(
+            logger.debug(
-                messages,
+                "Idle consolidation has no safe input budget for {}; raw-dumping",
-                runtime=runtime,
+                session.key,
-                session_key=session.key,
             )
+            self.store.raw_archive(messages, session_key=session.key)
+            return None
+        tools = self._get_tool_definitions()
         estimated, source = estimate_prompt_tokens_chain(
             runtime.provider,
             runtime.model,
@@ -1175,17 +1181,14 @@ class Consolidator:
         )
         if estimated > budget:
             logger.debug(
-                "Idle consolidation falling back to bounded archive for {}: {}/{} via {}",
+                "Idle consolidation prefix exceeds budget for {}; raw-dumping: {}/{} via {}",
                 session.key,
                 estimated,
                 budget,
                 source,
             )
-            return await self.archive(
+            self.store.raw_archive(messages, session_key=session.key)
-                messages,
+            return None
-                runtime=runtime,
-                session_key=session.key,
-            )
         return await self._archive_request(
             request_messages=request_messages,
             fallback_messages=messages,

tests/agent/test_consolidator.py

@@ -634,6 +634,15 @@ class TestConsolidatorTokenBudget:
 class TestCompactIdleSession:
     """Idle compaction tests."""
 
+    @pytest.fixture
+    def runtime(self, mock_provider):
+        """Exercise the structured idle-consolidation path by default."""
+        return LLMRuntime.capture(
+            mock_provider,
+            "test-model",
+            context_window_tokens=128_000,
+        )
+
     @pytest.fixture
     def real_consolidator(self, store, mock_provider):
         """Create a Consolidator with a real SessionManager (not a mock)."""
@@ -713,7 +722,6 @@ class TestCompactIdleSession:
     async def test_new_messages_advance_existing_archive_progress(
         self, real_consolidator, mock_provider, runtime
     ):
-        runtime = replace(runtime, context_window_tokens=128_000)
         mock_provider.chat_with_retry.return_value = MagicMock(
             content="Summary.", finish_reason="stop"
         )
@@ -773,7 +781,6 @@ class TestCompactIdleSession:
         the recent suffix it retains. Otherwise a late user correction / final
         result that lands in the kept suffix is excluded from the persisted
         summary, leaving a stale wrong conclusion in history. Regression for #4264."""
-        runtime = replace(runtime, context_window_tokens=128_000)
         mock_provider.chat_with_retry.return_value = MagicMock(
             content="Summary.", finish_reason="stop"
         )
@@ -934,7 +941,6 @@ class TestCompactIdleSession:
         self, real_consolidator, mock_provider, runtime
     ):
         """30 turns with last_consolidated=50 → only unconsolidated tail considered."""
-        runtime = replace(runtime, context_window_tokens=128_000)
         mock_provider.chat_with_retry.return_value = MagicMock(
             content="Tail summary.", finish_reason="stop"
         )
@@ -972,7 +978,6 @@ class TestCompactIdleSession:
         mock_provider,
         runtime,
     ):
-        runtime = replace(runtime, context_window_tokens=128_000)
         mock_provider.chat_with_retry.return_value = MagicMock(
             content="Tail summary.", finish_reason="stop"
         )
@@ -1023,7 +1028,6 @@ class TestCompactIdleSession:
         store,
         runtime,
     ):
-        runtime = replace(runtime, context_window_tokens=128_000)
         tools = [{"type": "function", "function": {"name": "lookup"}}]
         real_consolidator._get_tool_definitions.return_value = tools
         mock_provider.chat_with_retry.return_value = LLMResponse(
@@ -1102,23 +1106,44 @@ class TestCompactIdleSession:
         assert sessions.get_or_create("cli:unexpected-tool").last_consolidated == 2
 
     @pytest.mark.asyncio
-    async def test_oversized_prefix_falls_back_to_bounded_archive(
+    async def test_empty_response_uses_raw_fallback(
         self,
         real_consolidator,
         mock_provider,
         store,
         runtime,
     ):
-        async def bounded_chat(**kwargs):
+        mock_provider.chat_with_retry.return_value = LLMResponse(
-            sent_chars = sum(
+            content="",
-                len(str(message.get("content") or ""))
+            finish_reason="stop",
-                for message in kwargs["messages"]
         )
-            if sent_chars > 20_000:
+        sessions = real_consolidator.sessions
-                return LLMResponse(content="context too long", finish_reason="error")
+        session = sessions.get_or_create("cli:empty-summary")
-            return LLMResponse(content="Bounded summary.", finish_reason="stop")
+        session.add_message("user", "remember this")
+        session.add_message("assistant", "important answer")
+        sessions.save(session)
 
-        mock_provider.chat_with_retry.side_effect = bounded_chat
+        result = await real_consolidator.compact_idle_session(
+            "cli:empty-summary",
+            runtime=runtime,
+        )
+
+        assert result is None
+        entries = store.read_unprocessed_history(since_cursor=0)
+        assert len(entries) == 1
+        assert entries[0]["content"].startswith("[RAW] ")
+        assert "important answer" in entries[0]["content"]
+        assert sessions.get_or_create("cli:empty-summary").last_consolidated == 2
+
+    @pytest.mark.asyncio
+    async def test_oversized_prefix_raw_archives_without_flattened_llm_retry(
+        self,
+        real_consolidator,
+        mock_provider,
+        store,
+        runtime,
+    ):
+        runtime = replace(runtime, context_window_tokens=1_000)
         sessions = real_consolidator.sessions
         session = sessions.get_or_create("sdk:oversized")
         session.add_message("user", "x" * 100_000)
@@ -1129,13 +1154,11 @@ class TestCompactIdleSession:
             runtime=runtime,
         )
 
-        assert result == "Bounded summary."
+        assert result is None
-        sent = mock_provider.chat_with_retry.call_args.kwargs["messages"]
+        mock_provider.chat_with_retry.assert_not_awaited()
-        assert sum(len(str(message.get("content") or "")) for message in sent) < 20_000
+        entries = store.read_unprocessed_history(since_cursor=0)
-        assert not any(
+        assert len(entries) == 1
-            "[RAW]" in entry["content"]
+        assert entries[0]["content"].startswith("[RAW] ")
-            for entry in store.read_unprocessed_history(since_cursor=0)
-        )
         assert sessions.get_or_create("sdk:oversized").last_consolidated == 1
 
     @pytest.mark.asyncio
@@ -1145,7 +1168,6 @@ class TestCompactIdleSession:
         mock_provider,
         runtime,
     ):
-        runtime = replace(runtime, context_window_tokens=128_000)
         mock_provider.chat_with_retry.return_value = LLMResponse(
             content="Summary.",
             finish_reason="stop",