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 posted a self-contained, minimal, reproducible example. A maintainer can copy it and run it AS IS.

Package (Required)

• langchain
• langchain-openai
• langchain-anthropic
• langchain-classic
• langchain-core
• langchain-cli
• langchain-model-profiles
• langchain-tests
• langchain-text-splitters
• langchain-chroma
• langchain-deepseek
• langchain-exa
• langchain-fireworks
• langchain-groq
• langchain-huggingface
• langchain-mistralai
• langchain-nomic
• langchain-ollama
• langchain-perplexity
• langchain-prompty
• langchain-qdrant
• langchain-xai
• Other / not sure / general

Example Code (Python)

# test.py


from langchain_ollama.llms import OllamaLLM
import requests
import os

# expect the item to be hosted in some area on my local net..
print("DEBUG2", requests.get('http://ollama:11434/v1/models').status_code)
 
model_name="qwen3:8b"

model1 = OllamaLLM(model=model_name, base_url="ollama:11434")
model2 = OllamaLLM(model=model_name, base_url="somewherethatdoesntexist:11434")

# 
print( 
    "DEBUG URL that exists\n",
    model1.invoke("what is your knowladge cut off"))

try:
    print("DEBUG doesnt exist URL\n",
        model2.invoke("what is your knowladge cut off"))
    assert False
except Exception as ex:
    assert True
    pass

Error Message and Stack Trace (if applicable)

The above code will assert at the assert location. Showing that the OllamaLLM model that was installed with an invalid base_url should have failed. But it just ignores the base_url setting and talks to the wrong location..

Description

OllamaLLM parameter base_url is ignored

System Info

System Information

OS: Linux
OS Version: #35~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Oct 14 13:55:17 UTC 2
Python Version: 3.10.12 (main, Aug 15 2025, 14:32:43) [GCC 11.4.0]

Package Information

langchain_core: 1.0.3
langchain: 1.0.4
langsmith: 0.4.41
langchain_chroma: 1.0.0
langchain_mcp_adapters: 0.1.12
langchain_ollama: 1.0.0
langgraph_sdk: 0.2.9

Optional packages not installed

langserve

Other Dependencies

chromadb: 1.3.4
claude-agent-sdk: Installed. No version info available.
httpx: 0.28.1
jsonpatch: 1.33
langchain-anthropic: Installed. No version info available.
langchain-aws: Installed. No version info available.
langchain-azure-ai: Installed. No version info available.
langchain-community: 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-model-profiles: Installed. No version info available.
langchain-openai: Installed. No version info available.
langchain-perplexity: Installed. No version info available.
langchain-together: Installed. No version info available.
langchain-xai: Installed. No version info available.
langgraph: 1.0.2
langsmith-pyo3: Installed. No version info available.
mcp: 1.13.0
numpy: 2.2.6
ollama: 0.6.0
openai-agents: Installed. No version info available.
opentelemetry-api: 1.38.0
opentelemetry-exporter-otlp-proto-http: Installed. No version info available.
opentelemetry-sdk: 1.38.0
orjson: 3.11.4
packaging: 25.0
pydantic: 2.12.4
pytest: 8.4.2
pyyaml: 6.0.3
requests: 2.32.5
requests-toolbelt: 1.0.0
rich: 14.2.0
tenacity: 9.1.2
typing-extensions: 4.15.0
vcrpy: Installed. No version info available.
zstandard: 0.25.0