fix(session): preserve user turns in replay history

nanobot/agent/loop.py

@@ -1172,6 +1172,7 @@ class AgentLoop:
             "max_messages": self._max_messages,
             "max_tokens": self._replay_token_budget(),
             "include_timestamps": True,
+            "extend_to_user": True,
         }
         history = session.get_history(**_hist_kwargs)
         current_role = "assistant" if is_subagent else "user"
@@ -1447,6 +1448,7 @@ class AgentLoop:
             "max_messages": self._max_messages,
             "max_tokens": self._replay_token_budget(),
             "include_timestamps": True,
+            "extend_to_user": True,
         }
         ctx.history = ctx.session.get_history(**_hist_kwargs)
         self._runtime_events().record_turn_runtime(

nanobot/agent/memory.py

@@ -22,6 +22,7 @@ from nanobot.utils.helpers import (
     estimate_message_tokens,
     estimate_prompt_tokens_chain,
     find_legal_message_start,
+    recent_message_start_index,
     strip_think,
     truncate_text,
     truncate_text_to_tokens,
@@ -717,7 +718,13 @@ class Consolidator:
         if len(tail) <= replay_max_messages:
             return None
 
-        sliced = tail[-replay_max_messages:]
+        tail_messages = [message for _idx, message in tail]
+        start_idx = recent_message_start_index(
+            tail_messages,
+            replay_max_messages,
+            extend_to_user=True,
+        )
+        sliced = tail[start_idx:]
         for i, (_idx, message) in enumerate(sliced):
             if message.get("role") == "user":
                 start = i

nanobot/session/manager.py

@@ -19,6 +19,7 @@ from nanobot.utils.helpers import (
     estimate_message_tokens,
     find_legal_message_start,
     image_placeholder_text,
+    recent_message_start_index,
     safe_filename,
     strip_think,
 )
@@ -153,6 +154,7 @@ class Session:
         *,
         max_tokens: int = 0,
         include_timestamps: bool = False,
+        extend_to_user: bool = False,
     ) -> list[dict[str, Any]]:
         """Return unconsolidated messages for LLM input.
 
@@ -161,7 +163,12 @@ class Session:
         """
         unconsolidated = self.messages[self.last_consolidated:]
         max_messages = max_messages if max_messages > 0 else 120
-        sliced = unconsolidated[-max_messages:]
+        start_idx = recent_message_start_index(
+            unconsolidated,
+            max_messages,
+            extend_to_user=extend_to_user,
+        )
+        sliced = unconsolidated[start_idx:]
 
         # Avoid starting mid-turn when possible, except for proactive
         # assistant deliveries that the user may be replying to.

nanobot/utils/helpers.py

@@ -270,6 +270,30 @@ def truncate_text_to_tokens(text: str, max_tokens: int) -> str:
         return truncate_text(text, max_chars - suffix_chars)
 
 
+def recent_message_start_index(
+    messages: list[dict[str, Any]],
+    max_messages: int,
+    *,
+    extend_to_user: bool = False,
+) -> int:
+    """Return the start index for a recent replay window."""
+    if max_messages <= 0:
+        return len(messages)
+    start_idx = max(0, len(messages) - max_messages)
+    if not extend_to_user or len(messages) <= max_messages:
+        return start_idx
+
+    recovered_user = next(
+        (i for i in range(start_idx, -1, -1) if messages[i].get("role") == "user"),
+        None,
+    )
+    if recovered_user is None:
+        return start_idx
+    if recovered_user > 0 and messages[recovered_user - 1].get("_channel_delivery"):
+        return recovered_user - 1
+    return recovered_user
+
+
 def find_legal_message_start(messages: list[dict[str, Any]]) -> int:
     """Find the first index whose tool results have matching assistant calls."""
     declared: set[str] = set()