AddableUpdatesDict does not support right-side addition #33046
Description
Checked other resources
- This is a bug, not a usage question.
- I added a clear and descriptive title that summarizes this issue.
- 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).
- This is not related to the langchain-community package.
- I read what a minimal reproducible example is (https://stackoverflow.com/help/minimal-reproducible-example).
- I posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS.
Example Code
from dotenv import load_dotenv
from mcp import ClientSession, StdioServerParameters, types
from mcp.client.stdio import stdio_client
from langchain_core.messages import HumanMessage, AIMessage, SystemMessage
from langchain.agents import AgentExecutor
from langchain.memory import ConversationSummaryMemory
from langchain_mcp_adapters.tools import load_mcp_tools
from langchain_mcp_adapters.client import MultiServerMCPClient
from langgraph.prebuilt import create_react_agent
from contextlib import AsyncExitStack
import json
import asyncio
from module.llm.gpt_oss_20B import GPT_OSS_20B
import os
from typing import List
load_dotenv()
from pydantic import BaseModel, Field
class Onpremise_RAG_Agent:
def __init__(self):
self.exit_stack = AsyncExitStack()
self.llm = GPT_OSS_20B(
model_path = os.getenv("llm_model_path"),
host="localhost",
port=os.getenv("llm_port"),
gpu_devices=[int(x) for x in os.getenv("llm_gpu_devices","").split(",") if x != ''],
)
# Tools list
self.available_tools = []
# Prompts list
self.available_prompts = []
# Sessions dict maps tool/prompt names or resource URIs to MCP client sessions
self.messages = [] # 세션별 메시지
self.agent = None
self.prompt = (
"당신은 유용한 어시스턴트입니다. 다음의 규칙을 엄격하게 준수하여 답변하세요:\n"
"- 검색된 문서에 있는 정보만 사용하여 답변하세요. 문서에 없는 내용은 추측하지 마세요.\n"
"- 답변의 끝에는 반드시 사용한 문서의 출처(파일 이름, 페이지 번호 또는 행 번호)를 명확히 명시하세요.\n"
"- 답변은 명확하고 간결하게 작성하세요."
"- 생성된 답변이 사용자의 질문에 적절한 답이 되는지 논리적으로 생각하세요."
)
self.memory = ConversationSummaryMemory(
llm = self.llm,
memory_key="chat_history",
)
async def connect_to_mcp_servers(self):
try:
with open("server_config.json", "r") as file:
data = json.load(file)
client = MultiServerMCPClient(data)
self.available_tools.extend(await client.get_tools())
self.agent = create_react_agent(
self.llm,
tools = self.available_tools,
prompt=self.prompt,
)
#,response_format=AgentAnswerFormat)
self.agent_ex = AgentExecutor(
agent= self.agent,
tools= self.available_tools,
memory = self.memory
)
except Exception as e:
print(f"Error loading server config: {e}")
raise
async def process_query(self, query):
self.messages.append(HumanMessage(content=query))
while True:
# response = await self.agent.ainvoke(input={"messages" : self.messages})
response = await self.agent_ex.ainvoke(input={"messages" : self.messages})
# 메시지의 마지막 AIMessage를 찾아 출력
for message in reversed(response["messages"]):
if isinstance(message, AIMessage):
# Handle AIMessage content
if isinstance(message.content, str) and message.content.strip():
print(f"Assistant: {message.content}")
self.messages.append(message)
self.messages = await self._summarize_messages()
return
# API 환경에 맞게 수정된 메서드
async def invoke_agent(self, query: str, chat_history: List = None) -> dict:
"""단일 질문에 대해 에이전트를 실행하고 구조화된 답변을 반환합니다."""
if chat_history is None:
chat_history = []
messages = chat_history + [HumanMessage(content=query)]
response = await self.agent.ainvoke(input={"messages": messages})
if response:
return response
else:
# 에러 또는 예상치 못한 응답 형식 처리
return {"answer": "에이전트가 답변을 생성하지 못했습니다."}
async def _summarize_messages(self):
"""대화 기록을 요약합니다."""
# 이전 메시지들을 HumanMessage와 AIMessage로 결합
conversation_history = ""
for msg in self.messages:
if isinstance(msg, HumanMessage):
conversation_history += f"user: {msg.content}\n"
elif isinstance(msg, AIMessage):
conversation_history += f"assistant: {msg.content}\n"
elif isinstance(msg, SystemMessage):
conversation_history += f"history : {msg.content}\n"
summary_prompt = (
f"다음 대화 내용을 1000자 이내로 요약하여 중요한 정보와 맥락을 유지해 주세요.\n\n"
f"대화:\n{conversation_history}\n\n"
f"요약:"
)
try:
summary = await self.llm.ainvoke(input=[HumanMessage(content=summary_prompt)])
messages = [SystemMessage(content=summary.content)]
except Exception as e:
# 요약 실패 시 메시지 리스트를 초기화하여 토큰 초과 오류 방지
messages = []
return messages
async def chat_loop(self):
print("\nMCP Chatbot Started!")
print("Type your queries or 'quit' to exit.")
while True:
try:
query = input("\nQuery: ").strip()
if not query:
continue
if query.lower() == 'quit':
break
await self.process_query(query)
except Exception as e:
print(f"\nError: {str(e)}")
async def cleanup(self):
await self.exit_stack.aclose()
async def main():
chatbot = Onpremise_RAG_Agent()
try:
await chatbot.connect_to_mcp_servers()
await chatbot.chat_loop()
finally:
await chatbot.cleanup()
if __name__ == "__main__":
asyncio.run(main())Error Message and Stack Trace (if applicable)
Traceback (most recent call last):
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langchain/chains/base.py", line 209, in ainvoke
await self._acall(inputs, run_manager=run_manager)
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langchain/agents/agent.py", line 1669, in _acall
next_step_output = await self._atake_next_step(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langchain/agents/agent.py", line 1463, in _atake_next_step
[
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langchain/agents/agent.py", line 1491, in _aiter_next_step
output = await self._action_agent.aplan(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langchain/agents/agent.py", line 506, in aplan
final_output += chunk
File "/mnt/data1/anaconda3/envs/lit_gpt/lib/python3.12/site-packages/langgraph/pregel/io.py", line 133, in __radd__
raise TypeError("AddableUpdatesDict does not support right-side addition")
TypeError: AddableUpdatesDict does not support right-side additionDescription
I'm trying to use AgentExecutor.
but something is wrong.. It's ok when i use create_react_agent instance
System Info
System Information
OS: Linux
OS Version: #15~24.04.1-Ubuntu SMP Fri Jul 25 23:26:08 UTC 2025
Python Version: 3.12.9 | packaged by Anaconda, Inc. | (main, Feb 6 2025, 18:56:27) [GCC 11.2.0]
Package Information
langchain_core: 0.3.70
langchain: 0.3.26
langchain_community: 0.3.27
langsmith: 0.3.45
langchain_chroma: 0.2.4
langchain_cohere: 0.3.5
langchain_docling: 1.0.0
langchain_experimental: 0.3.4
langchain_google_genai: 2.1.7
langchain_groq: 0.3.4
langchain_huggingface: 0.3.1
langchain_mcp_adapters: 0.1.9
langchain_ollama: 0.3.6
langchain_openai: 0.2.14
langchain_pymupdf4llm: 0.4.1
langchain_text_splitters: 0.3.8
langchain_unstructured: 0.1.2
langgraph_sdk: 0.1.70
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.
chromadb>=1.0.9: Installed. No version info available.
cohere: 5.16.1
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
docling~=2.18: Installed. No version info available.
filetype: 1.2.0
google-ai-generativelanguage: 0.6.18
groq<1,>=0.28.0: Installed. No version info available.
httpx: 0.28.1
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
httpx>=0.25.2: Installed. No version info available.
huggingface-hub>=0.33.4: 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-azure-ai;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<0.4,>=0.3.36: Installed. No version info available.
langchain-core<1.0.0,>=0.3.51: Installed. No version info available.
langchain-core<1.0.0,>=0.3.66: Installed. No version info available.
langchain-core<1.0.0,>=0.3.70: Installed. No version info available.
langchain-core>=0.3.60: Installed. No version info available.
langchain-core~=0.3.19: 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-perplexity;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.8: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.26: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith>=0.1.125: Installed. No version info available.
langsmith>=0.1.17: Installed. No version info available.
langsmith>=0.3.45: Installed. No version info available.
mcp>=1.9.2: Installed. No version info available.
numpy>=1.26.0;: Installed. No version info available.
numpy>=1.26.2;: Installed. No version info available.
numpy>=2.1.0;: Installed. No version info available.
ollama<1.0.0,>=0.5.1: Installed. No version info available.
openai: 1.90.0
openai-agents: Installed. No version info available.
opentelemetry-api: 1.36.0
opentelemetry-exporter-otlp-proto-http: 1.36.0
opentelemetry-sdk: 1.36.0
orjson: 3.10.18
orjson>=3.10.1: Installed. No version info available.
packaging: 24.2
packaging>=23.2: Installed. No version info available.
pandas: 2.2.3
pydantic: 2.11.7
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic>=2.7.4: Installed. No version info available.
pymupdf4llm: 0.0.24
pytest: 8.3.5
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
sentence-transformers>=2.6.0;: Installed. No version info available.
SQLAlchemy<3,>=1.4: Installed. No version info available.
tabulate: 0.9.0
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.
tiktoken: 0.9.0
tokenizers>=0.19.1: Installed. No version info available.
transformers>=4.39.0;: Installed. No version info available.
typing-extensions>=4.14.0: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
unstructured-client: 0.24.1
unstructured[all-docs]: Installed. No version info available.
zstandard: 0.23.0