langchain-optiq

LangChain chat model for OptiQ Cloud. ChatOptiQ is a ChatOpenAI-style model with the OptiQ Cloud base URL, key and model ids set, plus reasoning_effort passed through to the API.

Installation

pip install -U langchain-optiq
export OPTIQ_API_KEY="sk-optiq-cloud-..."

Create a key on the OptiQ Cloud dashboard. OPTIQ_CLOUD_API_KEY, the name used in the OptiQ docs, is read when OPTIQ_API_KEY is not set.

Usage

from langchain_optiq import ChatOptiQ

llm = ChatOptiQ(model="deepseek-v4.1-flash", reasoning_effort="low")
print(llm.invoke("Name three uses of a hash map.").content)

Streaming, async, tool calling and structured output work as they do with ChatOpenAI:

from pydantic import BaseModel


class City(BaseModel):
    name: str
    country: str


llm = ChatOptiQ(model="glm-5.3-flash", reasoning_effort="minimal")
llm.with_structured_output(City).invoke("The capital of Japan")

for chunk in llm.stream("Write a haiku about caches."):
    print(chunk.content, end="")

Models

The current list, with prices, is at GET https://cloud.mlx-optiq.com/api/v1/models (no key needed). Any model id from that list can be passed as model.

Reasoning

Every model thinks before it answers, and thinking is billed as output. With no reasoning_effort, a model thinks fully. minimal or low thinks least on the models that always think. Only deepseek-v4.1-flash takes none, which turns thinking off. A value the model does not take comes back as a 400 before the model runs, so nothing is charged. The measured effect of each value is in the API reference.

When the API returns the thinking text, it is kept in message.additional_kwargs["reasoning_content"].

Configuration

Other ChatOpenAI arguments such as max_tokens, temperature, timeout, max_retries and default_headers are passed through. Sending the same x-session-id header on every call of one task keeps that task's prompt cache:

llm = ChatOptiQ(default_headers={"x-session-id": "task-42"})

Development

uv sync --all-groups
make test               # unit tests, network disabled
make integration_tests  # live API, needs OPTIQ_API_KEY
make lint

Links

• API reference: mlx-optiq.com/docs/cloud/api
• Other frameworks: mlx-optiq.com/docs/cloud/frameworks

License

MIT