langchain invalid namespace when trying to implement human in the loop

[kssgarcia]

I have a simple langgraph app made in TS and I am testing the implementation of human in the loop for this using MongoDBSaver and MemorySaver, but when I add this and the interrupts this error appear:

C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\core\dist\load\index.cjs:143
            throw new Error(`Invalid namespace: ${pathStr} -> ${str}`);
                  ^
Error: Invalid namespace: $ -> {"lc":1,"type":"constructor","id":["langchain","chat_models","groq","ChatGroq"],"kwargs":{"api_key":{"lc":1,"type":"secret","id":["GROQ_API_KEY"]},"model":"llama-3.1-70b-versatile","temperature":0}}
    at Object.reviver (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\core\dist\load\index.cjs:143:19)
    at load (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\core\dist\load\index.cjs:187:20)
    at _reviver (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\langgraph-checkpoint\dist\serde\jsonplus.cjs:92:36)      
    at _reviver (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\langgraph-checkpoint\dist\serde\jsonplus.cjs:100:39)     
    at _reviver (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\langgraph-checkpoint\dist\serde\jsonplus.cjs:100:39)     
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async MemorySaver.getTuple (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\langgraph-checkpoint\dist\memory.cjs:90:25)
    at async CompiledStateGraph.updateState (C:\Users\santy\OneDrive - Universidad EAFIT\Documents\DupperProject\DupperAPI\node_modules\@langchain\langgraph\dist\pregel\index.cjs:272:23)
[nodemon] app crashed - waiting for file changes before starting...

[dosubot[bot]]

Hello, @kssgarcia! I'm here to help you with any bugs, questions, or contributions you have. Let's tackle this together!

To resolve the "Invalid namespace" error when implementing human in the loop in your LangChain app using MongoDBSaver and MemorySaver, ensure that the namespace parameter in the MongoDBAtlasVectorSearch.from_connection_string method is correctly formatted. The namespace should be in the format database.collection.

Here is the relevant code snippet from the document:

from langchain_mongodb import MongoDBAtlasVectorSearch
from langchain_openai import OpenAIEmbeddings

embedding_model = OpenAIEmbeddings(model="text-embedding-3-small", dimensions=256)

# Vector Store Creation
vector_store = MongoDBAtlasVectorSearch.from_connection_string(
    connection_string=MONGO_URI,
    namespace=DB_NAME + "." + COLLECTION_NAME,  # Ensure this is correctly formatted
    embedding=embedding_model,
    index_name=ATLAS_VECTOR_SEARCH_INDEX_NAME,
    text_key="abstract",
)

Make sure that DB_NAME and COLLECTION_NAME are correctly defined and concatenated with a dot (.) to form a valid namespace. For example, if DB_NAME is "agent_demo" and COLLECTION_NAME is "knowledge", the namespace should be "agent_demo.knowledge" ^[1][2].

Additionally, the reviver function in the LangChain core module handles namespaces by checking if the namespace is valid and then using import mappings to import the appropriate module and class. If the namespace is not valid or the class is not a subclass of Serializable, it raises an error. Here is the relevant part of the reviver function:

def __call__(self, value: Dict[str, Any]) -> Any:
    if (
        value.get("lc", None) == 1
        and value.get("type", None) == "constructor"
        and value.get("id", None) is not None
    ):
        [*namespace, name] = value["id"]

        if namespace[0] not in self.valid_namespaces:
            raise ValueError(f"Invalid namespace: {value}")

        # The root namespace "langchain" is not a valid identifier.
        if len(namespace) == 1 and namespace[0] == "langchain":
            raise ValueError(f"Invalid namespace: {value}")

        # If namespace is in known namespaces, try to use mapping
        key = tuple(namespace + [name])
        if namespace[0] in DEFAULT_NAMESPACES:
            # Get the importable path
            if key not in self.import_mappings:
                raise ValueError(
                    "Trying to deserialize something that cannot "
                    "be deserialized in current version of langchain-core: "
                    f"{key}"
                )
            import_path = self.import_mappings[key]
            # Split into module and name
            import_dir, import_obj = import_path[:-1], import_path[-1]
            # Import module
            mod = importlib.import_module(".".join(import_dir))
            # Import class
            cls = getattr(mod, import_obj)
        # Otherwise, load by path
        else:
            if key in self.additional_import_mappings:
                import_path = self.import_mappings[key]
                mod = importlib.import_module(".".join(import_path[:-1]))
                name = import_path[-1]
            else:
                mod = importlib.import_module(".".join(namespace))
            cls = getattr(mod, name)

        # The class must be a subclass of Serializable.
        if not issubclass(cls, Serializable):
            raise ValueError(f"Invalid namespace: {value}")

        # We don't need to recurse on kwargs
        # as json.loads will do that for us.
        kwargs = value.get("kwargs", dict())
        return cls(**kwargs)

    return value

Ensure that the namespace and class names are correctly defined and valid ^[3].

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[kssgarcia]

I am using typescript

[jacoblee93]

Hey @kssgarcia, could you share your code? Happy to have a look - it looks like you might be storing a chat model in your state?