feat: stop creating new message for system prompt changes (#1559)

Co-authored-by: Sarah Wooders <sarahwooders@gmail.com>

letta/services/agent_manager.py

@@ -38,7 +38,7 @@ from letta.schemas.group import ManagerType
 from letta.schemas.llm_config import LLMConfig
 from letta.schemas.memory import Memory
 from letta.schemas.message import Message as PydanticMessage
-from letta.schemas.message import MessageCreate
+from letta.schemas.message import MessageCreate, MessageUpdate
 from letta.schemas.passage import Passage as PydanticPassage
 from letta.schemas.source import Source as PydanticSource
 from letta.schemas.tool import Tool as PydanticTool
@@ -718,10 +718,12 @@ class AgentManager:
                 model=agent_state.llm_config.model,
                 openai_message_dict={"role": "system", "content": new_system_message_str},
             )
-            # TODO: This seems kind of silly, why not just update the message?
-            message = self.message_manager.create_message(message, actor=actor)
-            message_ids = [message.id] + agent_state.message_ids[1:]  # swap index 0 (system)
-            return self.set_in_context_messages(agent_id=agent_id, message_ids=message_ids, actor=actor)
+            message = self.message_manager.update_message_by_id(
+                message_id=curr_system_message.id,
+                message_update=MessageUpdate(**message.model_dump()),
+                actor=actor,
+            )
+            return self.set_in_context_messages(agent_id=agent_id, message_ids=agent_state.message_ids, actor=actor)
         else:
             return agent_state
 

tests/test_server.py

@@ -279,8 +279,6 @@ def server():
 def org_id(server):
     # create org
     org = server.organization_manager.create_default_organization()
-    print(f"Created org\n{org.id}")
-
     yield org.id
 
     # cleanup
@@ -338,7 +336,6 @@ def agent_id(server, user_id, base_tools):
         ),
         actor=actor,
     )
-    print(f"Created agent\n{agent_state}")
     yield agent_state.id
 
     # cleanup
@@ -359,7 +356,6 @@ def other_agent_id(server, user_id, base_tools):
         ),
         actor=actor,
     )
-    print(f"Created agent\n{agent_state}")
     yield agent_state.id
 
     # cleanup
@@ -953,7 +949,6 @@ def test_memory_rebuild_count(server, user, disable_e2b_api_key, base_tools, bas
         ),
         actor=actor,
     )
-    print(f"Created agent\n{agent_state}")
 
     def count_system_messages_in_recall() -> Tuple[int, List[LettaMessage]]:
 
@@ -967,10 +962,6 @@ def test_memory_rebuild_count(server, user, disable_e2b_api_key, base_tools, bas
         )
         assert all(isinstance(m, LettaMessage) for m in letta_messages)
 
-        print("LETTA_MESSAGES:")
-        for i, m in enumerate(letta_messages):
-            print(f"{i}: {type(m)} ...{str(m)[-50:]}")
-
         # Collect system messages and their texts
         system_messages = [m for m in letta_messages if m.message_type == "system_message"]
         return len(system_messages), letta_messages