feat: summarize when tokenlimit exceeded or threshold reached

camel/memories/agent_memories.py

@@ -129,6 +129,16 @@ def clean_tool_calls(self) -> None:
         # Save the modified records back to storage
         self._chat_history_block.storage.save(record_dicts)
 
+    def pop_records(self, count: int) -> List[MemoryRecord]:
+        r"""Removes the most recent records from chat history memory."""
+        return self._chat_history_block.pop_records(count)
+
+    def remove_records_by_indices(
+        self, indices: List[int]
+    ) -> List[MemoryRecord]:
+        r"""Removes records at specified indices from chat history memory."""
+        return self._chat_history_block.remove_records_by_indices(indices)
+
 
 class VectorDBMemory(AgentMemory):
     r"""An agent memory wrapper of :obj:`VectorDBBlock`. This memory queries
@@ -193,6 +203,20 @@ def clear(self) -> None:
         r"""Removes all records from the vector database memory."""
         self._vectordb_block.clear()
 
+    def pop_records(self, count: int) -> List[MemoryRecord]:
+        r"""Rolling back is unsupported for vector database memory."""
+        raise NotImplementedError(
+            "VectorDBMemory does not support removing historical records."
+        )
+
+    def remove_records_by_indices(
+        self, indices: List[int]
+    ) -> List[MemoryRecord]:
+        r"""Removing by indices is unsupported for vector database memory."""
+        raise NotImplementedError(
+            "VectorDBMemory does not support removing records by indices."
+        )
+
 
 class LongtermAgentMemory(AgentMemory):
     r"""An implementation of the :obj:`AgentMemory` abstract base class for
@@ -277,3 +301,13 @@ def clear(self) -> None:
         r"""Removes all records from the memory."""
         self.chat_history_block.clear()
         self.vector_db_block.clear()
+
+    def pop_records(self, count: int) -> List[MemoryRecord]:
+        r"""Removes recent chat history records while leaving vector memory."""
+        return self.chat_history_block.pop_records(count)
+
+    def remove_records_by_indices(
+        self, indices: List[int]
+    ) -> List[MemoryRecord]:
+        r"""Removes records at specified indices from chat history."""
+        return self.chat_history_block.remove_records_by_indices(indices)

camel/memories/base.py

@@ -45,6 +45,32 @@ def write_record(self, record: MemoryRecord) -> None:
         """
         self.write_records([record])
 
+    def pop_records(self, count: int) -> List[MemoryRecord]:
+        r"""Removes records from the memory and returns the removed records.
+
+        Args:
+            count (int): Number of records to remove.
+
+        Returns:
+            List[MemoryRecord]: The records that were removed from the memory
+                in their original order.
+        """
+        raise NotImplementedError
+
+    def remove_records_by_indices(
+        self, indices: List[int]
+    ) -> List[MemoryRecord]:
+        r"""Removes records at specified indices from the memory.
+
+        Args:
+            indices (List[int]): List of indices to remove. Indices should be
+                valid positions in the current record list.
+
+        Returns:
+            List[MemoryRecord]: The removed records in their original order.
+        """
+        raise NotImplementedError
+
     @abstractmethod
     def clear(self) -> None:
         r"""Clears all messages from the memory."""

camel/memories/blocks/chat_history_block.py

@@ -167,3 +167,118 @@ def write_records(self, records: List[MemoryRecord]) -> None:
     def clear(self) -> None:
         r"""Clears all chat messages from the memory."""
         self.storage.clear()
+
+    def pop_records(self, count: int) -> List[MemoryRecord]:
+        r"""Removes the most recent records from the memory.
+
+        Args:
+            count (int): Number of records to remove from the end of the
+                conversation history. A value of 0 results in no changes.
+
+        Returns:
+            List[MemoryRecord]: The removed records in chronological order.
+        """
+        if not isinstance(count, int):
+            raise TypeError("`count` must be an integer.")
+        if count < 0:
+            raise ValueError("`count` must be non-negative.")
+        if count == 0:
+            return []
+
+        record_dicts = self.storage.load()
+        if not record_dicts:
+            return []
+
+        # Preserve initial system/developer instruction if present.
+        protected_prefix = (
+            1
+            if (
+                record_dicts
+                and record_dicts[0]['role_at_backend']
+                in {
+                    OpenAIBackendRole.SYSTEM.value,
+                    OpenAIBackendRole.DEVELOPER.value,
+                }
+            )
+            else 0
+        )
+
+        removable_count = max(len(record_dicts) - protected_prefix, 0)
+        if removable_count == 0:
+            return []
+
+        pop_count = min(count, removable_count)
+        split_index = len(record_dicts) - pop_count
+
+        popped_dicts = record_dicts[split_index:]
+        remaining_dicts = record_dicts[:split_index]
+
+        self.storage.clear()
+        if remaining_dicts:
+            self.storage.save(remaining_dicts)
+
+        return [MemoryRecord.from_dict(record) for record in popped_dicts]
+
+    def remove_records_by_indices(
+        self, indices: List[int]
+    ) -> List[MemoryRecord]:
+        r"""Removes records at specified indices from the memory.
+
+        Args:
+            indices (List[int]): List of indices to remove. Indices are
+                positions in the current record list (0-based).
+                System/developer messages at index 0 are protected and will
+                not be removed.
+
+        Returns:
+            List[MemoryRecord]: The removed records in their original order.
+        """
+        if not indices:
+            return []
+
+        record_dicts = self.storage.load()
+        if not record_dicts:
+            return []
+
+        # Preserve initial system/developer instruction if present.
+        protected_prefix = (
+            1
+            if (
+                record_dicts
+                and record_dicts[0]['role_at_backend']
+                in {
+                    OpenAIBackendRole.SYSTEM.value,
+                    OpenAIBackendRole.DEVELOPER.value,
+                }
+            )
+            else 0
+        )
+
+        # Filter out protected indices and invalid ones
+        valid_indices = sorted(
+            {
+                idx
+                for idx in indices
+                if idx >= protected_prefix and idx < len(record_dicts)
+            }
+        )
+
+        if not valid_indices:
+            return []
+
+        # Extract records to remove (in original order)
+        removed_records = [record_dicts[idx] for idx in valid_indices]
+
+        # Build remaining records by excluding removed indices
+        remaining_dicts = [
+            record
+            for idx, record in enumerate(record_dicts)
+            if idx not in valid_indices
+        ]
+
+        # Save back to storage
+        self.storage.clear()
+        if remaining_dicts:
+            self.storage.save(remaining_dicts)
+
+        return [MemoryRecord.from_dict(record) for record in removed_records]