Dynamo Chatmessage history

[VpkPrasanna]

Dynamo chatmessage history gives an error like
Error in RootListenersTracer.on_chain_end callback: TypeError('Float types are not supported. Use Decimal types instead.')

Nothing is storing in the Table , table has been created and here is how i am accessing
`prompt = ChatPromptTemplate.from_messages(
[
("system", Final_prompt),
MessagesPlaceholder(variable_name="history"),
("human", "{input}"),
])

    llm = ChatGroq(model="llama3-8b-8192",api_key=GROQ_API_KEY,temperature=0,max_tokens=50)
    chain = prompt | llm
    # chain_with_history = RunnableWithMessageHistory(
    # chain, get_dynamodb_history, input_messages_key="input", history_messages_key="history")
    chain_with_history = RunnableWithMessageHistory(
            chain,
            lambda session_id: DynamoDBChatMessageHistory(
                table_name="ConversationSessionTable", session_id=session_id
            ),
            input_messages_key="input",
            history_messages_key="history",
        )

    response1 = chain_with_history.invoke({"input": user_message},
                                        config={"configurable": {"session_id": session_id }})`

[dosubot[bot]]

To resolve the error TypeError('Float types are not supported. Use Decimal types instead.') when using DynamoDBChatMessageHistory, you need to ensure that any float values being stored in DynamoDB are converted to Decimal types. This is because DynamoDB does not support float types directly.

Here is a modified version of the add_message method that converts float values to Decimal before storing them in DynamoDB:

from decimal import Decimal

def add_message(self, message: BaseMessage) -> None:
    """Append the message to the record in DynamoDB"""
    try:
        from botocore.exceptions import ClientError
    except ImportError as e:
        raise ImportError(
            "Unable to import botocore, please install with `pip install botocore`."
        ) from e

    messages = messages_to_dict(self.messages)
    _message = message_to_dict(message)
    messages.append(_message)

    if self.history_size:
        messages = messages[-self.history_size:]

    # Convert float values to Decimal
    def convert_floats(item):
        if isinstance(item, list):
            return [convert_floats(i) for i in item]
        elif isinstance(item, dict):
            return {k: convert_floats(v) for k, v in item.items()}
        elif isinstance(item, float):
            return Decimal(str(item))
        return item

    messages = convert_floats(messages)

    try:
        if self.ttl:
            import time

            expireAt = int(time.time()) + self.ttl
            self.table.put_item(
                Item={
                    **self.key,
                    self.history_messages_key: messages,
                    self.ttl_key_name: expireAt,
                }
            )
        else:
            self.table.put_item(
                Item={**self.key, self.history_messages_key: messages}
            )
    except ClientError as err:
        logger.error(err)

This code includes a helper function convert_floats that recursively converts all float values in the messages to Decimal types before storing them in DynamoDB ^[1].

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[VpkPrasanna]

@dosu i have raised an PR for the same can someone from the team look into it . #26562