How can I fix the 'Member is not serializable' error when using chain memory in discord.py?

I'm building a discord bot using discord.py that leverages chain memory to generate AI responses during on_message events. The bot functions correctly when not using memory, but when I enable memory in my chain, I receive the error: TypeError: Object of type Member is not serializable.

I suspect the issue is caused by passing a discord.Member object (likely as the 'author' attribute) through the chain which eventually attempts to serialize the state. Below is the relevant portion of my code (some functions were removed for brevity):

PYTHONCopied
class WhiteTiger(discord.Client):
    def __init__(self, intents):
        super().__init__(intents=intents)
        self.target_channel = None
        self.llm = ChatOllama(
            model="llama3.2",
            temperature=0,
        )
        self.prompt = ChatPromptTemplate.from_messages(
            [
                (
                    "system",
                    "<context>",
                ),
                MessagesPlaceholder(variable_name="messages"),
            ]
        )
        self.chain = self.prompt | self.llm

        self.init_memory()

    def init_memory(self):
        workflow = StateGraph(state_schema=DiscordMessagesState)

        def call_model(state: DiscordMessagesState):
            response = self.chain.invoke(state)
            return {"messages": [response]}

        workflow.add_edge(START, "model")
        workflow.add_node("model", call_model)

        self.memory = MemorySaver()
        self.app = workflow.compile(checkpointer=self.memory)
        self.config = {"configurable": {"thread_id": "abc1234"}}


    async def on_message(self, message):
        if (
            self.target_channel
            and message.channel.id == self.target_channel.id
            and message.author.id != self.user.id
        ):  
            print(f"Message from {message.author}: {message.content}")

            print(f"{message.author}: {message.content}")

            reply = self.app.invoke(
                {
                    "messages": [HumanMessage(f"{message.author}: {message.content}")],
                    "author": message.author,
                },
                self.config
            )

            await message.reply(
                reply["messages"][-1].pretty_print(), mention_author=True
            )

The full traceback is available here: traceback image

I would like to understand how to resolve this error. Specifically, how can I modify the code to avoid serializing non-serializable objects like discord.Member while still retaining the required information (e.g., using member ID or name)?

Thanks in advance!