llm.invoke() encountered error for CreateCompletionRequestprompt str type expected

[zmin1217]

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Example Code

from langchain_openai import OpenAI
llm = OpenAI(
base_url="https://xxxxx",
api_key="sk-xxxxxxxxxxxxx",
model="DeepSeek-V3-0324-1874024892354772993",
)
response = llm.invoke("Hello, world!")

Description

I'm new to LangChain and encountered the following issue after running a simple demo.

Demo:

from langchain_openai import OpenAI
llm = OpenAI(
base_url="https://xxxxx",
api_key="sk-xxxxxxxxxxxxx",
model="DeepSeek-V3-0324-1874024892354772993",
)
response = llm.invoke("Hello, world!")

Error msg:

Traceback (most recent call last):
File "/Rec/Demo/agent_demo/agent_example.py", line 74, in
response = llm.invoke("Hello, world!")
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_core/language_models/llms.py", line 385, in invoke
self.generate_prompt(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_core/language_models/llms.py", line 750, in generate_prompt
return self.generate(prompt_strings, stop=stop, callbacks=callbacks, **kwargs)
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_core/language_models/llms.py", line 944, in generate
output = self._generate_helper(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_core/language_models/llms.py", line 787, in _generate_helper
raise e
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_core/language_models/llms.py", line 774, in _generate_helper
self._generate(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/langchain_openai/llms/base.py", line 348, in _generate
response = self.client.create(prompt=_prompts, **params)
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_utils/_utils.py", line 274, in wrapper
return func(*args, **kwargs)
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/resources/completions.py", line 528, in create
return self._post(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1259, in post
return cast(ResponseT, self.request(cast_to, opts, stream=stream, stream_cls=stream_cls))
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 936, in request
return self._request(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1025, in _request
return self._retry_request(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1074, in _retry_request
return self._request(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1025, in _request
return self._retry_request(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1074, in _retry_request
return self._request(
File "/opt/cloudera/parcels/Anaconda/envs/lang_demo/lib/python3.8/site-packages/openai/_base_client.py", line 1040, in _request
raise self._make_status_error_from_response(err.response) from None
openai.InternalServerError: Internal Server Error: 1 validation error for CreateCompletionRequestprompt str type expected (type=type_error.str)

System Info

langchain 0.2.17
langchain-community 0.2.19
langchain-core 0.2.43
langchain-openai 0.1.25