fix: remove dead last_consolidated field from Session

The `last_consolidated` marker was designed for incremental consolidation
assuming append-only messages. However, deferred trim removes messages from
the session, which broke the incremental assumption and caused consolidation
to fail silently (early exit when end_idx <= stale last_consolidated).

After trim, the session only contains NEW unconsolidated messages, making
the marker unnecessary. Consolidation now always starts from index 0,
processing all messages in the session (which are by definition not yet
consolidated due to trim).

Fixes the bug where extraction completely stopped working after trim
(zero facts extracted despite multiple consolidation attempts).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

nanobot/agent/memory.py

@@ -87,9 +87,7 @@ class MemoryStore:
             keep_count = memory_window // 2
             if len(session.messages) <= keep_count:
                 return True
-            if len(session.messages) - session.last_consolidated <= 0:
-                return True
-            old_messages = session.messages[session.last_consolidated:-keep_count]
+            old_messages = session.messages[:-keep_count]
             if not old_messages:
                 return True
             logger.info("Memory consolidation: {} to consolidate, {} keep", len(old_messages), keep_count)
@@ -142,8 +140,7 @@ class MemoryStore:
                 if update != current_memory:
                     self.write_long_term(update)
 
-            session.last_consolidated = 0 if archive_all else len(session.messages) - keep_count
-            logger.info("Memory consolidation done: {} messages, last_consolidated={}", len(session.messages), session.last_consolidated)
+            logger.info("Memory consolidation done: {} messages total", len(session.messages))
             return True
         except Exception:
             logger.exception("Memory consolidation failed")

nanobot/agent/memory_mem0.py

@@ -332,8 +332,8 @@ Here is the conversation to extract facts from:
                 if len(session.messages) <= keep_count:
                     return True
 
-                # Get unconsolidated messages
-                start_idx = session.last_consolidated
+                # Consolidate messages except the most recent (kept for context)
+                start_idx = 0
                 end_idx = len(session.messages) - keep_count
 
                 if end_idx <= start_idx:
@@ -414,15 +414,8 @@ Here is the conversation to extract facts from:
                     session_id=session.key
                 )
 
-            # Update consolidation marker
-            if archive_all:
-                session.last_consolidated = len(session.messages)
-            else:
-                session.last_consolidated = end_idx
-
             logger.info(
-                f"Mem0 consolidation done: {len(session.messages)} messages, "
-                f"last_consolidated={session.last_consolidated}"
+                f"Mem0 consolidation done: {len(session.messages)} messages total"
             )
             return True
 

nanobot/session/manager.py

@@ -19,9 +19,7 @@ class Session:
 
     Stores messages in JSONL format for easy reading and persistence.
 
-    Important: Messages are append-only for LLM cache efficiency.
-    The consolidation process writes summaries to MEMORY.md/HISTORY.md
-    but does NOT modify the messages list or get_history() output.
+    Messages are trimmed after consolidation to keep session size manageable.
     """
 
     key: str  # channel:chat_id
@@ -29,7 +27,6 @@ class Session:
     created_at: datetime = field(default_factory=datetime.now)
     updated_at: datetime = field(default_factory=datetime.now)
     metadata: dict[str, Any] = field(default_factory=dict)
-    last_consolidated: int = 0  # Number of messages already consolidated to files
     
     def add_message(self, role: str, content: str, **kwargs: Any) -> None:
         """Add a message to the session."""
@@ -73,7 +70,6 @@ class Session:
     def clear(self) -> None:
         """Clear all messages and reset session to initial state."""
         self.messages = []
-        self.last_consolidated = 0
         self.updated_at = datetime.now()
 
 
@@ -139,7 +135,6 @@ class SessionManager:
             messages = []
             metadata = {}
             created_at = None
-            last_consolidated = 0
 
             with open(path, encoding="utf-8") as f:
                 for line in f:
@@ -152,7 +147,7 @@ class SessionManager:
                     if data.get("_type") == "metadata":
                         metadata = data.get("metadata", {})
                         created_at = datetime.fromisoformat(data["created_at"]) if data.get("created_at") else None
-                        last_consolidated = data.get("last_consolidated", 0)
+                        # Ignore legacy last_consolidated field
                     else:
                         messages.append(data)
 
@@ -161,7 +156,6 @@ class SessionManager:
                 messages=messages,
                 created_at=created_at or datetime.now(),
                 metadata=metadata,
-                last_consolidated=last_consolidated
             )
         except Exception as e:
             logger.warning("Failed to load session {}: {}", key, e)
@@ -178,7 +172,6 @@ class SessionManager:
                 "created_at": session.created_at.isoformat(),
                 "updated_at": session.updated_at.isoformat(),
                 "metadata": session.metadata,
-                "last_consolidated": session.last_consolidated
             }
             f.write(json.dumps(metadata_line, ensure_ascii=False) + "\n")
             for msg in session.messages: