fix(harness): preserve dynamic context across summarization (#2823)

backend/packages/harness/deerflow/agents/middlewares/dynamic_context_middleware.py

@@ -45,6 +45,7 @@ logger = logging.getLogger(__name__)
 
 _DATE_RE = re.compile(r"<current_date>([^<]+)</current_date>")
 _DYNAMIC_CONTEXT_REMINDER_KEY = "dynamic_context_reminder"
+_SUMMARY_MESSAGE_NAME = "summary"
 
 
 def _extract_date(content: str) -> str | None:
@@ -72,6 +73,16 @@ def _last_injected_date(messages: list) -> str | None:
     return None
 
 
+def is_dynamic_context_reminder(message: object) -> bool:
+    """Return whether *message* is a hidden dynamic-context reminder."""
+    return isinstance(message, HumanMessage) and bool(message.additional_kwargs.get(_DYNAMIC_CONTEXT_REMINDER_KEY))
+
+
+def _is_user_injection_target(message: object) -> bool:
+    """Return whether *message* can receive a dynamic-context reminder."""
+    return isinstance(message, HumanMessage) and not is_dynamic_context_reminder(message) and message.name != _SUMMARY_MESSAGE_NAME
+
+
 class DynamicContextMiddleware(AgentMiddleware):
     """Inject memory and current date into HumanMessages as a <system-reminder>.
 
@@ -163,7 +174,7 @@ class DynamicContextMiddleware(AgentMiddleware):
 
         if last_date is None:
             # ── First turn: inject full reminder as a separate HumanMessage ─────
-            first_idx = next((i for i, m in enumerate(messages) if isinstance(m, HumanMessage)), None)
+            first_idx = next((i for i, m in enumerate(messages) if _is_user_injection_target(m)), None)
             if first_idx is None:
                 return None
             full_reminder = self._build_full_reminder()
@@ -181,7 +192,7 @@ class DynamicContextMiddleware(AgentMiddleware):
             return None
 
         # ── Midnight crossed: inject date-update reminder as a separate HumanMessage ──
-        last_human_idx = next((i for i in reversed(range(len(messages))) if isinstance(messages[i], HumanMessage)), None)
+        last_human_idx = next((i for i in reversed(range(len(messages))) if _is_user_injection_target(messages[i])), None)
         if last_human_idx is None:
             return None
 

backend/packages/harness/deerflow/agents/middlewares/summarization_middleware.py

@@ -14,6 +14,7 @@ from langgraph.config import get_config
 from langgraph.graph.message import REMOVE_ALL_MESSAGES
 from langgraph.runtime import Runtime
 
+from deerflow.agents.middlewares.dynamic_context_middleware import is_dynamic_context_reminder
 from deerflow.agents.middlewares.tool_call_metadata import clone_ai_message_with_tool_calls
 
 logger = logging.getLogger(__name__)
@@ -135,6 +136,7 @@ class DeerFlowSummarizationMiddleware(SummarizationMiddleware):
             return None
 
         messages_to_summarize, preserved_messages = self._partition_with_skill_rescue(messages, cutoff_index)
+        messages_to_summarize, preserved_messages = self._preserve_dynamic_context_reminders(messages_to_summarize, preserved_messages)
         self._fire_hooks(messages_to_summarize, preserved_messages, runtime)
         summary = self._create_summary(messages_to_summarize)
         new_messages = self._build_new_messages(summary)
@@ -160,6 +162,7 @@ class DeerFlowSummarizationMiddleware(SummarizationMiddleware):
             return None
 
         messages_to_summarize, preserved_messages = self._partition_with_skill_rescue(messages, cutoff_index)
+        messages_to_summarize, preserved_messages = self._preserve_dynamic_context_reminders(messages_to_summarize, preserved_messages)
         self._fire_hooks(messages_to_summarize, preserved_messages, runtime)
         summary = await self._acreate_summary(messages_to_summarize)
         new_messages = self._build_new_messages(summary)
@@ -179,6 +182,24 @@ class DeerFlowSummarizationMiddleware(SummarizationMiddleware):
         """
         return [HumanMessage(content=f"Here is a summary of the conversation to date:\n\n{summary}", name="summary")]
 
+    def _preserve_dynamic_context_reminders(
+        self,
+        messages_to_summarize: list[AnyMessage],
+        preserved_messages: list[AnyMessage],
+    ) -> tuple[list[AnyMessage], list[AnyMessage]]:
+        """Keep hidden dynamic-context reminders out of summary compression.
+
+        These reminders carry the current date and optional memory. If summarization
+        removes them, DynamicContextMiddleware can mistake the summary HumanMessage
+        for the first user message and inject the reminder in the wrong place.
+        """
+        reminders = [msg for msg in messages_to_summarize if is_dynamic_context_reminder(msg)]
+        if not reminders:
+            return messages_to_summarize, preserved_messages
+
+        remaining = [msg for msg in messages_to_summarize if not is_dynamic_context_reminder(msg)]
+        return remaining, reminders + preserved_messages
+
     def _partition_with_skill_rescue(
         self,
         messages: list[AnyMessage],