ChatOpenRouter()Application URL for OpenRouter attribution.
Maps to HTTP-Referer header.
Defaults to LangChain docs URL. Set this to your app's URL to get attribution for API usage in the OpenRouter dashboard.
See https://openrouter.ai/docs/app-attribution for details.
Application title for OpenRouter attribution.
Maps to X-Title header.
Defaults to 'LangChain'. Set this to your app's name to get attribution
for API usage in the OpenRouter dashboard.
See https://openrouter.ai/docs/app-attribution for details.
Marketplace categories for OpenRouter attribution.
Maps to X-OpenRouter-Categories header. Pass a list of lowercase,
hyphen-separated category strings (max 30 characters each),
e.g. ['cli-agent', 'programming-app'].
Only recognized categories are accepted (unrecognized values are silently dropped by OpenRouter).
See https://openrouter.ai/docs/app-attribution for recognized categories.
Reasoning settings to pass to OpenRouter.
Controls how many tokens the model allocates for internal chain-of-thought reasoning.
Accepts an openrouter.components.OpenResponsesReasoningConfig or an
equivalent dict.
Supported keys:
effort: Controls reasoning token budget.
Values: 'xhigh', 'high', 'medium', 'low', 'minimal', 'none'.
summary: Controls verbosity of the reasoning summary returned in the
response.
Values: 'auto', 'concise', 'detailed'.
Example: {"effort": "high", "summary": "auto"}
See https://openrouter.ai/docs/guides/best-practices/reasoning-tokens
OpenRouter chat model integration.
OpenRouter is a unified API that provides access to hundreds of models from multiple providers (OpenAI, Anthropic, Google, Meta, etc.).
Install langchain-openrouter and set environment variable
OPENROUTER_API_KEY.
pip install -U langchain-openrouterexport OPENROUTER_API_KEY="your-api-key"| Param | Type | Description |
|---|---|---|
model |
str |
Model name, e.g. 'openai/gpt-4o-mini'. |
temperature |
float | None |
Sampling temperature. |
max_tokens |
int | None |
Max tokens to generate. |
| Param | Type | Description |
|---|---|---|
api_key |
str | None |
OpenRouter API key. |
base_url |
str | None |
Base URL for API requests. |
timeout |
int | None |
Timeout in milliseconds. |
app_url |
str | None |
App URL for attribution. |
app_title |
str | None |
App title for attribution. |
app_categories |
list[str] | None |
Marketplace attribution categories. |
max_retries |
int |
Max retries (default 2). Set to 0 to disable. |
from langchain_openrouter import ChatOpenRouter
model = ChatOpenRouter(
model="anthropic/claude-sonnet-4-5",
temperature=0,
# api_key="...",
# openrouter_provider={"order": ["Anthropic"]},
)See https://openrouter.ai/docs for platform documentation.