Agent with memory gives InvalidSqlStatementName error

[HasnainKhanNiazi]

from dotenv import load_dotenv
load_dotenv()

from typing import (
    Annotated,
    Sequence,
    TypedDict,
)
from langchain_core.messages import BaseMessage
from langgraph.graph.message import add_messages
from langchain_openai import ChatOpenAI
from tools_new import TOOLS
import json
from langchain_core.messages import ToolMessage, SystemMessage
from langchain_core.runnables import RunnableConfig
from langgraph.graph import StateGraph, END
from prompt import prompt
from langchain_core.messages import HumanMessage
import asyncio
from psycopg import AsyncConnection
import os
from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
from rich.console import Console
rich = Console()

connection_kwargs = {
    "autocommit": True,
    "prepare_threshold": 0,
}

model = ChatOpenAI(model="gpt-4o", temperature=0)

class AgentState(TypedDict):
    """The state of the agent."""

    messages: Annotated[Sequence[BaseMessage], add_messages]

model = model.bind_tools(TOOLS)
tools_by_name = {tool.name: tool for tool in TOOLS}

def tool_node(state: AgentState):
    outputs = []
    for tool_call in state["messages"][-1].tool_calls:
        tool_result = tools_by_name[tool_call["name"]].invoke(tool_call["args"])
        outputs.append(
            ToolMessage(
                content=json.dumps(tool_result),
                name=tool_call["name"],
                tool_call_id=tool_call["id"],
            )
        )
    return {"messages": outputs}

def call_model(
    state: AgentState,
    config: RunnableConfig,
):
    system_prompt = SystemMessage(
        prompt
    )
    response = model.invoke([system_prompt] + state["messages"], config)
    return {"messages": [response]}

def should_continue(state: AgentState):
    messages = state["messages"]
    last_message = messages[-1]
    if not last_message.tool_calls:
        return "end"
    else:
        return "continue"

# Define a new graph
workflow = StateGraph(AgentState)

workflow.add_node("agent", call_model)
workflow.add_node("tools", tool_node)

workflow.set_entry_point("agent")

# We now add a conditional edge
workflow.add_conditional_edges(
    "agent",
    should_continue,
    {
        "continue": "tools",
        "end": END,
    },
)

workflow.add_edge("tools", "agent")

async def run_graph(user_input: str, thread_id: str):
    with AsyncConnection.connect(os.getenv("DB_URI"), **connection_kwargs) as conn:
        checkpointer = AsyncPostgresSaver(conn)
        await checkpointer.setup()
        graph = workflow.compile(checkpointer=checkpointer)
        config = {"configurable": {"thread_id": thread_id}}
        async for event in graph.astream_events(
            {"messages": [HumanMessage(content=user_input)]},
            version = 'v2', stream_mode="values", config=config
        ):
            if "on_chat_model_stream" == event['event']:
                if len(event['data']["chunk"].content) > 0:
                    print(event['data']['chunk'].content, end='', flush=True)

if __name__ == '__main__':
    print("Running model")
    asyncio.run(run_graph(user_input="How are you?", thread_id="testing5"))

DB_URI= postgresql://USER:[email protected]:6543/postgres?sslmode=disable

I am using above code for react-agent with memory. Without memory, agent is working fine but when I add memory to it then sometime it gives me this error and sometime it works fine. I am not sure what could be wrong.

psycopg.errors.InvalidSqlStatementName: prepared statement "_pg3_14" does not exist