How to add human response with subgraphs (Web API)

[ai-rayven]

I am not sure if I am thinking about this correctly. Currently, I have a langgraph implementation that utilizes many nested subgraphs and any of the subgraphs can interrupt to wait for a human response. When I only had one graph it wasn't too difficult to inject the message back into the state, although it feels a bit hacky (function below).

Is there a better way to handle this case for single graphs and multiple nested subgraphs? Thanks for your help.

 async def clear_memory(self, config: AgentConfig) -> None:
        """
        Clear the memory by setting an empty checkpoint.

        Args:
            config (AgentConfig): The agent configuration.
        """
        checkpoint = empty_checkpoint()
        await self.checkpointer.aput(config=config, checkpoint=checkpoint, metadata={"step": 0}, new_versions=None)

    async def reset_state(self, tracker: AgentStateTracker, config: AgentConfig, user_message: str) -> Dict[str, Any]:
        """
        Reset the state of the agent.

        Args:
            tracker (AgentStateTracker): The state tracker.
            config (AgentConfig): The agent configuration.
            user_message (str): The user message to initialize the state with.

        Returns:
            Dict[str, Any]: The initial state.
        """
        state = self.create_initial_state(tracker, config, user_message)
        await self.clear_memory(config)
        return state

async def determine_initial_state(self, existing_state: Any, tracker: AgentStateTracker, config: AgentConfig, request: AgentRunRequest) -> Dict[str, Any]:
        """
        Determine the initial state for the agent workflow.

        Args:
            existing_state (Any): The existing state.
            tracker (AgentStateTracker): The state tracker.
            config (AgentConfig): The agent configuration.
            request (AgentRunRequest): The agent run request.

        Returns:
            Dict[str, Any]: The initial state.
        """
        if existing_state and existing_state.values["messages"] and len(existing_state.next) > 0:
            tracker.add_messages(existing_state.values["messages"])
            tracker.add_events(existing_state.values["events"])

            if len(tracker.messages) > 0 and "human_feedback" in self.agent_factory.create(self.agent_name).nodes:
                last_message = tracker.last_message()
                if isinstance(last_message, AIMessage):
                    user_message = HumanMessage(content=request.user_message, id=str(uuid.uuid4()))
                    new_state = existing_state.values
                    new_state["messages"] = [user_message]
                    await self.agent_factory.create(self.agent_name).aupdate_state(config, new_state, as_node="human_feedback")
                    tracker.add_message(user_message)
            else:
                return await self.reset_state(tracker, config, request.user_message)
        else:
            if existing_state.created_at is None:
                return self.create_initial_state(tracker, config, request.user_message)
            else:
                return await self.reset_state(tracker, config, request.user_message)

[Nowina]

@ai-rayven I'm working on solving very similar problem, you set the issue as resolved. Can you share your solution?