Bugs when bind tools in _create_message_from_message_type()

[MILK-BIOS]

Checked other resources

• I added a very descriptive title to this issue.
• I searched the LangChain documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

Hi Langchain Team! The following code:

def _create_message_from_message_type(
    message_type: str,
    content: str,
    name: Optional[str] = None,
    tool_call_id: Optional[str] = None,
    tool_calls: Optional[list[dict[str, Any]]] = None,
    id: Optional[str] = None,
    **additional_kwargs: Any,
) -> BaseMessage:
    """Create a message from a message type and content string.

    Args:
        message_type: (str) the type of the message (e.g., "human", "ai", etc.).
        content: (str) the content string.
        name: (str) the name of the message. Default is None.
        tool_call_id: (str) the tool call id. Default is None.
        tool_calls: (list[dict[str, Any]]) the tool calls. Default is None.
        id: (str) the id of the message. Default is None.
        additional_kwargs: (dict[str, Any]) additional keyword arguments.

    Returns:
        a message of the appropriate type.

    Raises:
        ValueError: if the message type is not one of "human", "user", "ai",
            "assistant", "function", "tool", "system", or "developer".
    """
    kwargs: dict[str, Any] = {}
    if name is not None:
        kwargs["name"] = name
    if tool_call_id is not None:
        kwargs["tool_call_id"] = tool_call_id
    if additional_kwargs:
        if response_metadata := additional_kwargs.pop("response_metadata", None):
            kwargs["response_metadata"] = response_metadata
        kwargs["additional_kwargs"] = additional_kwargs  # type: ignore[assignment]
        additional_kwargs.update(additional_kwargs.pop("additional_kwargs", {}))
    if id is not None:
        kwargs["id"] = id
    if tool_calls is not None:
        kwargs["tool_calls"] = []
        for tool_call in tool_calls:
            # Convert OpenAI-format tool call to LangChain format.
            if "function" in tool_call:
                args = tool_call["function"]["arguments"]
                if isinstance(args, str):
                    args = json.loads(args, strict=False)
                kwargs["tool_calls"].append(
                    {
                        "name": tool_call["function"]["name"],
                        "args": args,
                        "id": tool_call["id"],
                        "type": "tool_call",
                    }
                )
            else:
                kwargs["tool_calls"].append(tool_call)
    if message_type in ("human", "user"):
        if example := kwargs.get("additional_kwargs", {}).pop("example", False):
            kwargs["example"] = example
        message: BaseMessage = HumanMessage(content=content, **kwargs)
    elif message_type in ("ai", "assistant"):
        if example := kwargs.get("additional_kwargs", {}).pop("example", False):
            kwargs["example"] = example
        message = AIMessage(content=content, **kwargs)
    elif message_type in ("system", "developer"):
        if message_type == "developer":
            kwargs["additional_kwargs"] = kwargs.get("additional_kwargs") or {}
            kwargs["additional_kwargs"]["__openai_role__"] = "developer"
        message = SystemMessage(content=content, **kwargs)
    elif message_type == "function":
        message = FunctionMessage(content=content, **kwargs)
    elif message_type == "tool":
        artifact = kwargs.get("additional_kwargs", {}).pop("artifact", None)
        message = ToolMessage(content=content, artifact=artifact, **kwargs)
    elif message_type == "remove":
        message = RemoveMessage(**kwargs)
    else:
        msg = (
            f"Unexpected message type: '{message_type}'. Use one of 'human',"
            f" 'user', 'ai', 'assistant', 'function', 'tool', 'system', or 'developer'."
        )
        msg = create_message(message=msg, error_code=ErrorCode.MESSAGE_COERCION_FAILURE)
        raise ValueError(msg)
    return message

Error Message and Stack Trace (if applicable)

发生异常: JSONDecodeError (note: full exception trace is shown but execution is paused at: _run_module_as_main)
Expecting value: line 1 column 1 (char 0)
File "/opt/conda/envs/yolox/lib/python3.10/json/decoder.py", line 353, in raw_decode
obj, end = self.scan_once(s, idx)
StopIteration: 0

During handling of the above exception, another exception occurred:

File "/opt/conda/envs/yolox/lib/python3.10/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
File "/opt/conda/envs/yolox/lib/python3.10/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/opt/conda/envs/yolox/lib/python3.10/json/init.py", line 359, in loads
return cls(**kw).decode(s)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langchain_core/messages/utils.py", line 252, in _create_message_from_message_type
args = json.loads(args, strict=False)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langchain_core/messages/utils.py", line 337, in _convert_to_message
_message = _create_message_from_message_type(
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langchain_core/messages/utils.py", line 364, in
return [_convert_to_message(m) for m in messages]
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langchain_core/messages/utils.py", line 364, in convert_to_messages
return [_convert_to_message(m) for m in messages]
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/graph/message.py", line 173, in add_messages
for m in convert_to_messages(right)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/graph/message.py", line 36, in _add_messages
return func(left, right, **kwargs)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/channels/binop.py", line 88, in update
self.value = self.operator(self.value, value)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/algo.py", line 305, in apply_writes
if channels[chan].update(vals) and get_next_version is not None:
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/algo.py", line 201, in local_read
apply_writes(copy_checkpoint(checkpoint), local_channels, [task], None)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/read.py", line 109, in do_read
return read(select, fresh)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/graph/graph.py", line 87, in _route
value = reader(config)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/utils/runnable.py", line 310, in invoke
ret = context.run(self.func, *args, **kwargs)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/utils/runnable.py", line 548, in invoke
input = step.invoke(input, config)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/retry.py", line 40, in run_with_retry
return task.proc.invoke(task.input, config)
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/runner.py", line 230, in tick
run_with_retry(
File "/opt/conda/envs/yolox/lib/python3.10/site-packages/langgraph/pregel/init.py", line 1993, in stream
for _ in runner.tick(
File "/private/workspace/fhs/AN/agents/router.py", line 150, in stream_graph_updates
for event in graph.stream({"messages": [{"role": "user", "content": user_input}]}):
File "/private/workspace/fhs/AN/agents/router.py", line 174, in
stream_graph_updates(user_input)
File "/opt/conda/envs/yolox/lib/python3.10/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "/opt/conda/envs/yolox/lib/python3.10/runpy.py", line 196, in _run_module_as_main (Current frame)
return _run_code(code, main_globals, None,
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Description

I'm trying to bind tools with Deepseek-R1. I have followed the code to edit my prompt. In above fuction, when args is str, it is still required to transform into json.

if isinstance(args, str):
   args = json.loads(args, strict=False)

Is it correct? Thanks for your time!

System Info

System Information

OS: Linux
OS Version: #113-Ubuntu SMP Thu Feb 3 18:43:29 UTC 2022
Python Version: 3.10.16 | packaged by conda-forge | (main, Dec 5 2024, 14:16:10) [GCC 13.3.0]

Package Information

langchain_core: 0.3.40
langchain: 0.3.19
langchain_community: 0.3.18
langsmith: 0.3.11
langchain_google_community: 2.0.7
langchain_ollama: 0.2.3
langchain_text_splitters: 0.3.6
langgraph_sdk: 0.1.53

Optional packages not installed

langserve

Other Dependencies

aiohttp<4.0.0,>=3.8.3: Installed. No version info available.
async-timeout<5.0.0,>=4.0.0;: Installed. No version info available.
beautifulsoup4: Installed. No version info available.
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
db-dtypes: Installed. No version info available.
gapic-google-longrunning: Installed. No version info available.
google-api-core: 2.24.1
google-api-python-client: 2.162.0
google-auth: 2.38.0
google-auth-httplib2: 0.2.0
google-auth-oauthlib: Installed. No version info available.
google-cloud-aiplatform: Installed. No version info available.
google-cloud-bigquery: Installed. No version info available.
google-cloud-bigquery-storage: Installed. No version info available.
google-cloud-contentwarehouse: Installed. No version info available.
google-cloud-core: 2.4.2
google-cloud-discoveryengine: Installed. No version info available.
google-cloud-documentai: Installed. No version info available.
google-cloud-documentai-toolbox: Installed. No version info available.
google-cloud-speech: Installed. No version info available.
google-cloud-storage: Installed. No version info available.
google-cloud-texttospeech: Installed. No version info available.
google-cloud-translate: Installed. No version info available.
google-cloud-vision: Installed. No version info available.
googlemaps: Installed. No version info available.
grpcio: 1.70.0
httpx: 0.28.1
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
jsonpatch<2.0,>=1.33: Installed. No version info available.
langchain-anthropic;: Installed. No version info available.
langchain-aws;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<1.0.0,>=0.3.34: Installed. No version info available.
langchain-core<1.0.0,>=0.3.35: Installed. No version info available.
langchain-core<1.0.0,>=0.3.37: Installed. No version info available.
langchain-deepseek;: Installed. No version info available.
langchain-fireworks;: Installed. No version info available.
langchain-google-genai;: Installed. No version info available.
langchain-google-vertexai;: Installed. No version info available.
langchain-groq;: Installed. No version info available.
langchain-huggingface;: Installed. No version info available.
langchain-mistralai;: Installed. No version info available.
langchain-ollama;: Installed. No version info available.
langchain-openai;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.6: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.19: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith<0.4,>=0.1.125: Installed. No version info available.
langsmith<0.4,>=0.1.17: Installed. No version info available.
numpy<2,>=1.26.4;: Installed. No version info available.
numpy<3,>=1.26.2;: Installed. No version info available.
ollama: 0.4.7
orjson: 3.10.7
packaging: 24.2
packaging<25,>=23.2: Installed. No version info available.
pandas: 2.2.3
pyarrow: 19.0.1
pydantic: 2.10.6
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.5.2;: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic<3.0.0,>=2.7.4;: Installed. No version info available.
pytest: Installed. No version info available.
PyYAML>=5.3: Installed. No version info available.
requests: 2.32.3
requests-toolbelt: 1.0.0
requests<3,>=2: Installed. No version info available.
rich: 13.9.4
SQLAlchemy<3,>=1.4: Installed. No version info available.
tenacity!=8.4.0,<10,>=8.1.0: Installed. No version info available.
tenacity!=8.4.0,<10.0.0,>=8.1.0: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
zstandard: 0.23.0

[andrasfe]

can you please provide a code snippet to reproduce the error?