langchain-ai/langgraph · error · LangGraphDeprecatedSinceV10

MessageGraph is deprecated in LangGraph v1.0.0, to be remove

Error message

MessageGraph is deprecated in LangGraph v1.0.0, to be removed in v2.0.0. Please use StateGraph with a `messages` key instead.

What it means

Error "MessageGraph is deprecated in LangGraph v1.0.0, to be removed in v2.0.0. Please use StateGraph with a `messages` key instead." thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/graph/message.py:364

        ...             tool_calls=[{"name": "search", "id": "123", "args": {"query": "X"}}],
        ...         )
        ...     ],
        ... )
        >>> builder.add_node(
        ...     "search", lambda state: [ToolMessage(content="Searching...", tool_call_id="123")]
        ... )
        >>> builder.set_entry_point("chatbot")
        >>> builder.add_edge("chatbot", "search")
        >>> builder.set_finish_point("search")
        >>> builder.compile().invoke([HumanMessage(content="Hi there. Can you search for X?")])
        {'messages': [HumanMessage(content="Hi there. Can you search for X?", id='b8b7d8f4-7f4d-4f4d-9c1d-f8b8d8f4d9c1'),
                     AIMessage(content="Hello!", id='f4d9c1d8-8d8f-4d9c-b8b7-d8f4f4d9c1d8'),
                     ToolMessage(content="Searching...", id='d8f4f4d9-c1d8-4f4d-b8b7-d8f4f4d9c1d8', tool_call_id="123")]}
        ```
    """

    def __init__(self) -> None:
        warnings.warn(
            "MessageGraph is deprecated in LangGraph v1.0.0, to be removed in v2.0.0. Please use StateGraph with a `messages` key instead.",
            category=LangGraphDeprecatedSinceV10,
            stacklevel=2,
        )
        super().__init__(Annotated[list[AnyMessage], add_messages])  # type: ignore[arg-type]


class MessagesState(TypedDict):
    messages: Annotated[list[AnyMessage], add_messages]


def _format_messages(messages: Sequence[BaseMessage]) -> list[BaseMessage]:
    try:
        from langchain_core.messages import convert_to_openai_messages
    except ImportError:
        msg = (
            "Must have langchain-core>=0.3.11 installed to use automatic message "
            "formatting (format='langchain-openai'). Please update your langchain-core "

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/graph/message.py:364 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of langchain-ai/langgraph@38031739e5 (2026-08-26). Data as JSON: /api/errors/21845681f647e7b0. Report an issue: GitHub.