> ## Documentation Index
> Fetch the complete documentation index at: https://docs.orq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# LangChain framework integration

> Connect LangChain to the AI Gateway for enhanced LLM orchestration. Use Orq.ai as a drop-in provider for chains, agents, and RAG applications.

## AI Gateway

### Overview

LangChain is a framework for building LLM-powered applications through composable chains, agents, and integrations with external data sources. Connecting LangChain to Orq.ai's AI Gateway provides access to 300+ models through a single base URL change.

### Key Benefits

Orq.ai's AI Gateway enhances LangChain applications with:

<CardGroup cols={2}>
  <Card title="Complete Observability" icon="chart-line">
    Track every chain step, tool use, and LLM call with detailed traces
  </Card>

  <Card title="Built-in Reliability" icon="shield-check">
    Automatic fallbacks, retries, and load balancing for production resilience
  </Card>

  <Card title="Cost Optimization" icon="chart-pie">
    Real-time cost tracking and spend management across all AI operations
  </Card>

  <Card title="Multi-Provider Access" icon="cubes">
    Access 300+ LLMs and 20+ providers through a single, unified integration
  </Card>
</CardGroup>

### Prerequisites

Before integrating LangChain with Orq.ai, ensure the following are in place:

* An Orq.ai account and [API Key](/docs/ai-gateway/configuration/api-keys)
* Python 3.9 or higher

<Info>
  To set up an API key, see [API keys & Endpoints](/docs/ai-gateway/configuration/api-keys).
</Info>

### Installation

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
pip install langchain langchain-openai
```

### Configuration

Configure LangChain to use Orq.ai's AI Gateway via `ChatOpenAI` with a custom `base_url`:

```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
from langchain_openai import ChatOpenAI
import os

llm = ChatOpenAI(
    model="openai/gpt-4o",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)
```

> **base\_url**: `https://api.orq.ai/v3/router`

### Basic Example

```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
from langchain_openai import ChatOpenAI
import os

llm = ChatOpenAI(
    model="openai/gpt-4o",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)

result = llm.invoke("Explain quantum computing in simple terms.")
print(result.content)
```

### Chains

Build composable chains using LangChain's pipe operator:

```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate
import os

llm = ChatOpenAI(
    model="openai/gpt-4o",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)

prompt = ChatPromptTemplate.from_messages([
    ("system", "You are a helpful assistant."),
    ("user", "{input}"),
])

chain = prompt | llm
result = chain.invoke({"input": "Tell me a joke about programming."})
print(result.content)
```

### Streaming

```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
from langchain_openai import ChatOpenAI
import os

llm = ChatOpenAI(
    model="openai/gpt-4o",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)

for chunk in llm.stream("Write a short poem about the ocean."):
    print(chunk.content, end="", flush=True)
print()
```

### Model Selection

With Orq.ai, any supported model from 20+ providers can be used:

```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
from langchain_openai import ChatOpenAI
import os

# Use Claude
claude = ChatOpenAI(
    model="anthropic/claude-sonnet-4-6",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)

# Use Gemini
gemini = ChatOpenAI(
    model="google-ai/gemini-2.5-flash",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)

# Use Groq
groq = ChatOpenAI(
    model="groq/llama-3.3-70b-versatile",
    api_key=os.getenv("ORQ_API_KEY"),
    base_url="https://api.orq.ai/v3/router",
)
```