# ![Atomic Chat logo](https://models.dev/logos/atomic-chat.svg)Atomic Chat

Access 5 Atomic Chat models through Mastra's model router. Authentication is handled automatically using the `ATOMIC_CHAT_API_KEY` environment variable.

Learn more in the [Atomic Chat documentation](https://atomic.chat).

```bash
ATOMIC_CHAT_API_KEY=your-api-key
```

```typescript
import { Agent } from "@mastra/core/agent";

const agent = new Agent({
  id: "my-agent",
  name: "My Agent",
  instructions: "You are a helpful assistant",
  model: "atomic-chat/Meta-Llama-3_1-8B-Instruct-GGUF"
});

// Generate a response
const response = await agent.generate("Hello!");

// Stream a response
const stream = await agent.stream("Tell me a story");
for await (const chunk of stream) {
  console.log(chunk);
}
```

> **Info:** Mastra uses the OpenAI-compatible `/chat/completions` endpoint. Some provider-specific features may not be available. Check the [Atomic Chat documentation](https://atomic.chat) for details.

## Models

| Model                                         | Context | Tools | Reasoning | Image | Audio | Video | Input $/1M | Output $/1M |
| --------------------------------------------- | ------- | ----- | --------- | ----- | ----- | ----- | ---------- | ----------- |
| `atomic-chat/gemma-4-E4B-it-IQ4_XS`           | 33K     |       |           |       |       |       | —          | —           |
| `atomic-chat/gemma-4-E4B-it-MLX-4bit`         | 33K     |       |           |       |       |       | —          | —           |
| `atomic-chat/Meta-Llama-3_1-8B-Instruct-GGUF` | 131K    |       |           |       |       |       | —          | —           |
| `atomic-chat/Qwen3_5-9B-MLX-4bit`             | 33K     |       |           |       |       |       | —          | —           |
| `atomic-chat/Qwen3_5-9B-Q4_K_M`               | 33K     |       |           |       |       |       | —          | —           |

## Advanced configuration

### Custom headers

```typescript
const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "http://127.0.0.1:1337/v1",
    id: "atomic-chat/Meta-Llama-3_1-8B-Instruct-GGUF",
    apiKey: process.env.ATOMIC_CHAT_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});
```

### Dynamic model selection

```typescript
const agent = new Agent({
  id: "dynamic-agent",
  name: "Dynamic Agent",
  model: ({ requestContext }) => {
    const useAdvanced = requestContext.task === "complex";
    return useAdvanced
      ? "atomic-chat/gemma-4-E4B-it-MLX-4bit"
      : "atomic-chat/Meta-Llama-3_1-8B-Instruct-GGUF";
  }
});
```