Task Manager

BaseTaskManager

BaseTaskManager is the main integration point in EAA. It owns:

• the model object
• the registered tools
• long-term memory
• SQLite persistence
• graph compilation and execution
• active transcript state

Construction options that matter most in practice are:

• llm_config
• memory_config
• tools
• skill_dirs
• checkpoint_db_path
• use_webui
• use_coding_tools
• run_codes_in_sandbox
• prune_checkpoints

Built-in graphs

Chat graph

build_chat_graph() creates the reusable conversation graph. It:

• accepts bootstrap input or waits for user input
• calls the model
• executes any tool calls
• returns to user input when the assistant produces a plain response

This is what backs run_conversation() and run_conversation_from_checkpoint().

Customization

Custom graph

build_task_graph() is the hook for a task-manager-specific LangGraph workflow. The base class returns None; if you want a custom graph, override it and implement run() or run_from_checkpoint() around it.

from langgraph.graph import END, START, StateGraph

from eaa_core.task_manager.base import BaseTaskManager
from eaa_core.task_manager.state import TaskManagerState


class CustomState(TaskManagerState):
    pass


class CustomTaskManager(BaseTaskManager):
    def build_task_graph(self, checkpointer=None):
        builder = StateGraph(CustomState)
        builder.add_node("call_model", self.node_factory.call_model, input_schema=CustomState)
        builder.add_edge(START, "call_model")
        builder.add_edge("call_model", END)
        return builder.compile(checkpointer=checkpointer)

    def run(self):
        initial_state = CustomState(
            messages=list(self.context),
            full_history=list(self.full_history),
        )
        graph = self.task_graph
        graph_kwargs = {}
        if self.checkpoint_db_path is not None:
            graph, checkpoint_config, _ = self.get_checkpointed_graph(
                "task_graph",
                load_state=False,
            )
            self.task_graph = graph
            graph_kwargs["config"] = checkpoint_config
        final_state = graph.invoke(initial_state, **graph_kwargs)
        self.set_active_state(CustomState.model_validate(final_state), "task_graph")

Status note: The repository currently does not ship built-in task-manager subclasses that define their own task_graph. The custom graph hook is present for extension work.

Custom workflow without a graph

Several analytical task managers in the repository do not rely on a custom LangGraph workflow. Instead, they orchestrate the experiment directly in Python and keep the agent-owned transcript updated through task-manager helpers.

The relevant helpers are:

• record_system_message() for narrative progress updates
• update_message_history() for explicit transcript mutations
• add_webui_message_to_db() for display-only transcript messages
• run_conversation() if control should fall back to free-form chat after the analytical workflow finishes

This pattern is used heavily in AnalyticalScanningMicroscopeFocusingTaskManager: the code performs explicit steps, emits status messages as it goes, and can still enter chat mode at the end.

Checkpointing and resume

Checkpointing uses the same SQLite database referenced by checkpoint_db_path by default. The run_*_from_checkpoint() methods also accept a checkpoint_db_path override when you need to resume from a different SQLite file. The checkpoint database stores LangGraph checkpoints.

WebUI display messages live in transcript_db_path. Browser input and status live in the task-manager-owned runtime controller.

The base task manager exposes two resume paths:

• run_conversation_from_checkpoint()
• run_from_checkpoint() for managers that implement task_graph

Important details:

• prune_checkpoints=True keeps only the newest checkpoint per graph thread
• chat and task graph each get their own checkpoint thread id
• the WebUI reads transcript messages from transcript_db_path through the agent runtime API