> Discover all available pages from the documentation index: https://mastra.zisheng.pro/ja/llms.txt

# ![FastRouter ロゴ](https://models.dev/logos/fastrouter.svg)FastRouter

Mastra のモデルルーターを通じて 47 個の FastRouter モデルを利用できます。認証には `FASTROUTER_API_KEY` 環境変数が自動的に使用されます。

詳しくは、[FastRouter のドキュメント](https://fastrouter.ai/models)を参照してください。

```bash
FASTROUTER_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: "fastrouter/anthropic/claude-opus-4.1"
});

// 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);
}
```

> **情報:** Mastra は OpenAI 互換の `/chat/completions` endpoint を使用します。一部の Provider 固有機能は利用できない場合があります。詳しくは、[FastRouter のドキュメント](https://fastrouter.ai/models)を確認してください。

## モデル

| Model                                                  | Context | Tools | Reasoning | Image | Audio | Video | Input $/1M | Output $/1M |
| ------------------------------------------------------ | ------- | ----- | --------- | ----- | ----- | ----- | ---------- | ----------- |
| `fastrouter/anthropic/claude-opus-4.1`                 | 200K    |       |           |       |       |       | $15        | $75         |
| `fastrouter/anthropic/claude-opus-4.8`                 | 1.0M    |       |           |       |       |       | $5         | $25         |
| `fastrouter/anthropic/claude-sonnet-4`                 | 200K    |       |           |       |       |       | $3         | $15         |
| `fastrouter/anthropic/claude-sonnet-4.6`               | 1.0M    |       |           |       |       |       | $3         | $15         |
| `fastrouter/bytedance/seedance-2`                      | 4K      |       |           |       |       |       | —          | —           |
| `fastrouter/deepseek-ai/deepseek-r1-distill-llama-70b` | 131K    |       |           |       |       |       | $0.03      | $0.14       |
| `fastrouter/deepseek/deepseek-v4-pro`                  | 1.0M    |       |           |       |       |       | $2         | $3          |
| `fastrouter/google/gemini-2.5-flash`                   | 1.0M    |       |           |       |       |       | $0.30      | $3          |
| `fastrouter/google/gemini-2.5-pro`                     | 1.0M    |       |           |       |       |       | $1         | $10         |
| `fastrouter/google/gemini-3-pro-image-preview`         | 66K     |       |           |       |       |       | $2         | $12         |
| `fastrouter/google/gemini-3.1-flash-image-preview`     | 66K     |       |           |       |       |       | $0.50      | $3          |
| `fastrouter/google/gemini-3.1-pro-preview`             | 1.0M    |       |           |       |       |       | $2         | $12         |
| `fastrouter/google/gemini-3.5-flash`                   | 1.0M    |       |           |       |       |       | $2         | $9          |
| `fastrouter/google/gemma-4-31b-it`                     | 262K    |       |           |       |       |       | $0.13      | $0.38       |
| `fastrouter/google/imagen-4.0-fast`                    | 480     |       |           |       |       |       | —          | —           |
| `fastrouter/google/imagen-4.0-ultra`                   | 480     |       |           |       |       |       | —          | —           |
| `fastrouter/google/veo3.1`                             | 400K    |       |           |       |       |       | —          | —           |
| `fastrouter/google/veo3.1-fast`                        | 400K    |       |           |       |       |       | —          | —           |
| `fastrouter/google/veo3.1-lite`                        | 400K    |       |           |       |       |       | —          | —           |
| `fastrouter/leonardo-ai/lucid-origin`                  | 4K      |       |           |       |       |       | —          | —           |
| `fastrouter/leonardo-ai/lucid-realism`                 | 4K      |       |           |       |       |       | —          | —           |
| `fastrouter/minimax/minimax-m2.7`                      | 205K    |       |           |       |       |       | $0.30      | $1          |
| `fastrouter/minimax/minimax-m2.7-highspeed`            | 205K    |       |           |       |       |       | $0.60      | $2          |
| `fastrouter/moonshotai/kimi-k2`                        | 131K    |       |           |       |       |       | $0.55      | $2          |
| `fastrouter/moonshotai/kimi-k2.6`                      | 262K    |       |           |       |       |       | $0.75      | $4          |
| `fastrouter/openai/gpt-4.1`                            | 1.0M    |       |           |       |       |       | $2         | $8          |
| `fastrouter/openai/gpt-5`                              | 400K    |       |           |       |       |       | $1         | $10         |
| `fastrouter/openai/gpt-5-mini`                         | 400K    |       |           |       |       |       | $0.25      | $2          |
| `fastrouter/openai/gpt-5-nano`                         | 400K    |       |           |       |       |       | $0.05      | $0.40       |
| `fastrouter/openai/gpt-5.3-codex`                      | 400K    |       |           |       |       |       | $2         | $14         |
| `fastrouter/openai/gpt-5.4-mini`                       | 400K    |       |           |       |       |       | $0.75      | $5          |
| `fastrouter/openai/gpt-5.4-nano`                       | 400K    |       |           |       |       |       | $0.20      | $1          |
| `fastrouter/openai/gpt-5.5`                            | 1.1M    |       |           |       |       |       | $5         | $30         |
| `fastrouter/openai/gpt-5.5-pro`                        | 1.1M    |       |           |       |       |       | $30        | $180        |
| `fastrouter/openai/gpt-image-2`                        | 128K    |       |           |       |       |       | —          | —           |
| `fastrouter/openai/gpt-oss-120b`                       | 131K    |       |           |       |       |       | $0.15      | $0.60       |
| `fastrouter/openai/gpt-oss-20b`                        | 131K    |       |           |       |       |       | $0.05      | $0.20       |
| `fastrouter/openai/gpt-realtime-1.5`                   | 32K     |       |           |       |       |       | $4         | $16         |
| `fastrouter/qwen/qwen3-coder`                          | 262K    |       |           |       |       |       | $0.30      | $1          |
| `fastrouter/sarvam/sarvam-105b`                        | 131K    |       |           |       |       |       | $0.04      | $0.16       |
| `fastrouter/sarvam/sarvam-30b`                         | 128K    |       |           |       |       |       | $0.02      | $0.10       |
| `fastrouter/wanx/wan-v2-6`                             | 400K    |       |           |       |       |       | —          | —           |
| `fastrouter/x-ai/grok-4`                               | 256K    |       |           |       |       |       | $3         | $15         |
| `fastrouter/x-ai/grok-4.3`                             | 1.0M    |       |           |       |       |       | $1         | $3          |
| `fastrouter/x-ai/grok-build-0.1`                       | 256K    |       |           |       |       |       | $1         | $2          |
| `fastrouter/z-ai/glm-5`                                | 205K    |       |           |       |       |       | $0.95      | $3          |
| `fastrouter/z-ai/glm-5.1`                              | 200K    |       |           |       |       |       | $1         | $4          |

## 高度な設定

### カスタムヘッダー

```typescript
const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "https://go.fastrouter.ai/api/v1",
    id: "fastrouter/anthropic/claude-opus-4.1",
    apiKey: process.env.FASTROUTER_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});
```

### 動的なモデル選択

```typescript
const agent = new Agent({
  id: "dynamic-agent",
  name: "Dynamic Agent",
  model: ({ requestContext }) => {
    const useAdvanced = requestContext.task === "complex";
    return useAdvanced
      ? "fastrouter/z-ai/glm-5.1"
      : "fastrouter/anthropic/claude-opus-4.1";
  }
});
```