revert nanobot

backend/app/core/nanobot.py

@@ -2,7 +2,7 @@ import asyncio
 import sys
 import os
 from pathlib import Path
-from typing import List, Callable, Awaitable
+from typing import List, Callable, Awaitable, Any
 
 # Add project root to sys.path to allow importing nanobot
 # Assuming backend/app/core/nanobot.py -> backend/app/core -> backend/app -> backend -> root
@@ -255,6 +255,12 @@ class NanobotIntegration:
                 # Append user message after skills
                 full_message = f"{skill_context}\n\n{message}"
 
+        session = agent_to_use.sessions.get_or_create(session_id)
+        normalized_messages = self._normalize_session_messages(session.messages)
+        if len(normalized_messages) != len(session.messages):
+            session.messages = normalized_messages
+            agent_to_use.sessions.save(session)
+
         response = await agent_to_use.process_direct(
             full_message,
             session_key=session_id,
@@ -264,4 +270,16 @@ class NanobotIntegration:
         )
         return response
 
+    def _normalize_session_messages(self, messages: List[Any]) -> List[dict[str, Any]]:
+        normalized: List[dict[str, Any]] = []
+        stack: List[Any] = list(messages)
+        while stack:
+            current = stack.pop(0)
+            if isinstance(current, dict):
+                normalized.append(current)
+                continue
+            if isinstance(current, list):
+                stack = list(current) + stack
+        return normalized
+
 nanobot_service = NanobotIntegration()

nanobot/nanobot/providers/base.py

@@ -95,15 +95,6 @@ class LLMProvider(ABC):
         """Keep only provider-safe message keys and normalize assistant content."""
         sanitized = []
         for msg in messages:
-            if isinstance(msg, list):
-                for nested in msg:
-                    if not isinstance(nested, dict):
-                        continue
-                    clean = {k: v for k, v in nested.items() if k in allowed_keys}
-                    if clean.get("role") == "assistant" and "content" not in clean:
-                        clean["content"] = None
-                    sanitized.append(clean)
-                continue
             if not isinstance(msg, dict):
                 continue
             clean = {k: v for k, v in msg.items() if k in allowed_keys}