todos.py

from langchain.agents import AgentState as BaseAgentState
from langchain.tools import ToolRuntime, tool
from langchain.messages import ToolMessage
from langgraph.types import Command
from typing import TypedDict, Literal
import uuid

class Todo(TypedDict):
    id: str
    title: str
    description: str
    emoji: str
    status: Literal["pending", "completed"]

class AgentState(BaseAgentState):
    todos: list[Todo]

@tool
def manage_todos(todos: list[Todo], runtime: ToolRuntime) -> Command:
    """
    Manage the current todos.
    """
    # Ensure all todos have IDs that are unique
    for todo in todos:
        if "id" not in todo or not todo["id"]:
            todo["id"] = str(uuid.uuid4())

    # Update the state
    return Command(update={
        "todos": todos,
        "messages": [
            ToolMessage(
                content="Successfully updated todos",
                tool_call_id=runtime.tool_call_id
            )
        ]
    })

@tool
def get_todos(runtime: ToolRuntime):
    """
    Get the current todos.
    """
    return runtime.state.get("todos", [])

todo_tools = [
    manage_todos,
    get_todos,
]