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

# OpenRouter

[OpenRouter](https://openrouter.ai) is a unified API that provides access to multiple LLM providers through a single OpenAI-compatible interface. Switch between Claude, Gemini, GPT, and more without changing your code.

<Info>
  Vision Agents requires a [Stream](https://getstream.io/try-for-free/) account
  for real-time transport. Most providers offer free tiers to get started.
</Info>

## Installation

```sh theme={null}
uv add "vision-agents[openrouter]"
```

## Quick Start

```python theme={null}
from vision_agents.core import User, Agent
from vision_agents.plugins import openrouter, getstream, elevenlabs, deepgram

agent = Agent(
    edge=getstream.Edge(),
    agent_user=User(name="Assistant", id="agent"),
    instructions="You are a helpful assistant.",
    llm=openrouter.LLM(model="anthropic/claude-sonnet-4"),
    tts=elevenlabs.TTS(),
    stt=deepgram.STT(),
)
```

<Warning>
  Set `OPENROUTER_API_KEY` in your environment or pass `api_key` directly.
</Warning>

## Parameters

| Name               | Type  | Default                          | Description                                                             |
| ------------------ | ----- | -------------------------------- | ----------------------------------------------------------------------- |
| `model`            | `str` | `"openrouter/andromeda-alpha"`   | Model identifier (see [available models](https://openrouter.ai/models)) |
| `api_key`          | `str` | `None`                           | API key (defaults to `OPENROUTER_API_KEY` env var)                      |
| `base_url`         | `str` | `"https://openrouter.ai/api/v1"` | API base URL                                                            |
| `tools_max_rounds` | `int` | `3`                              | Maximum tool-call rounds per response                                   |

## Available Models

| Provider  | Model ID                                                         |
| --------- | ---------------------------------------------------------------- |
| Anthropic | `anthropic/claude-sonnet-4`, `anthropic/claude-opus-4`           |
| Google    | `google/gemini-3-flash-preview`, `google/gemini-3.1-pro-preview` |
| OpenAI    | `openai/gpt-5.4`, `openai/gpt-5.4`                               |

See [OpenRouter Models](https://openrouter.ai/models) for the full list.

## Next Steps

<CardGroup cols={2}>
  <Card title="Build a Voice Agent" icon="microphone" href="/introduction/voice-agents">
    Get started with voice
  </Card>

  <Card title="Build a Video Agent" icon="video" href="/introduction/video-agents">
    Add video processing
  </Card>
</CardGroup>