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

# ![Opper logo](https://models.dev/logos/opper.svg)Opper

Access 40 Opper models through Mastra's model router. Authentication is handled automatically using the `OPPER_API_KEY` environment variable.

Learn more in the [Opper documentation](https://opper.ai/models).

```bash
OPPER_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: "opper/anthropic/claude-fable-5"
});

// 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);
}
```

> **Note:** Mastra uses the OpenAI-compatible `/chat/completions` endpoint. Some provider-specific features may not be available. Check the [Opper documentation](https://opper.ai/models) for details.

## Models

| Model                                  | Context | Tools | Reasoning | Image | Audio | Video | Input $/1M | Output $/1M |
| -------------------------------------- | ------- | ----- | --------- | ----- | ----- | ----- | ---------- | ----------- |
| `opper/anthropic/claude-fable-5`       | 1.0M    |       |           |       |       |       | $10        | $50         |
| `opper/anthropic/claude-haiku-4-5`     | 200K    |       |           |       |       |       | $1         | $5          |
| `opper/anthropic/claude-opus-4-5`      | 200K    |       |           |       |       |       | $5         | $25         |
| `opper/anthropic/claude-opus-4-6`      | 1.0M    |       |           |       |       |       | $5         | $25         |
| `opper/anthropic/claude-opus-4-7`      | 1.0M    |       |           |       |       |       | $5         | $25         |
| `opper/anthropic/claude-opus-4-8`      | 1.0M    |       |           |       |       |       | $5         | $25         |
| `opper/anthropic/claude-opus-5`        | 1.0M    |       |           |       |       |       | $5         | $25         |
| `opper/anthropic/claude-sonnet-4-5`    | 200K    |       |           |       |       |       | $3         | $15         |
| `opper/anthropic/claude-sonnet-4-6`    | 1.0M    |       |           |       |       |       | $3         | $15         |
| `opper/anthropic/claude-sonnet-5`      | 1.0M    |       |           |       |       |       | $2         | $10         |
| `opper/gemini/gemini-3-flash-preview`  | 1.0M    |       |           |       |       |       | $0.50      | $3          |
| `opper/gemini/gemini-3.1-pro-preview`  | 1.0M    |       |           |       |       |       | $2         | $12         |
| `opper/gemini/gemini-3.5-flash`        | 1.0M    |       |           |       |       |       | $2         | $9          |
| `opper/gemini/gemini-3.5-flash-lite`   | 1.0M    |       |           |       |       |       | $0.30      | $3          |
| `opper/meta/muse-spark-1.2`            | 1.0M    |       |           |       |       |       | $1         | $4          |
| `opper/minimax/m3`                     | 1.0M    |       |           |       |       |       | $0.60      | $2          |
| `opper/mistral/devstral-2512`          | 262K    |       |           |       |       |       | $0.40      | $2          |
| `opper/mistral/mistral-large-2512`     | 262K    |       |           |       |       |       | $0.50      | $2          |
| `opper/mistral/mistral-small-2603`     | 256K    |       |           |       |       |       | $0.15      | $0.60       |
| `opper/moonshot/kimi-k3`               | 1.0M    |       |           |       |       |       | $3         | $15         |
| `opper/openai/gpt-5.3-chat-latest`     | 128K    |       |           |       |       |       | $2         | $14         |
| `opper/openai/gpt-5.3-codex`           | 400K    |       |           |       |       |       | $2         | $14         |
| `opper/openai/gpt-5.4`                 | 1.1M    |       |           |       |       |       | $3         | $15         |
| `opper/openai/gpt-5.4-mini`            | 400K    |       |           |       |       |       | $0.75      | $5          |
| `opper/openai/gpt-5.4-nano`            | 400K    |       |           |       |       |       | $0.20      | $1          |
| `opper/openai/gpt-5.4-pro`             | 1.1M    |       |           |       |       |       | $30        | $180        |
| `opper/openai/gpt-5.5`                 | 1.1M    |       |           |       |       |       | $5         | $30         |
| `opper/openai/gpt-5.5-pro`             | 1.1M    |       |           |       |       |       | $30        | $180        |
| `opper/openai/gpt-5.6-luna`            | 1.1M    |       |           |       |       |       | $0.20      | $1          |
| `opper/openai/gpt-5.6-sol`             | 1.1M    |       |           |       |       |       | $5         | $30         |
| `opper/openai/gpt-5.6-terra`           | 1.1M    |       |           |       |       |       | $2         | $12         |
| `opper/perplexity/sonar`               | 128K    |       |           |       |       |       | $1         | $1          |
| `opper/perplexity/sonar-pro`           | 200K    |       |           |       |       |       | $3         | $15         |
| `opper/perplexity/sonar-reasoning-pro` | 128K    |       |           |       |       |       | $2         | $8          |
| `opper/vertexai/gemini-3.7-flash`      | 1.0M    |       |           |       |       |       | $0.75      | $4          |
| `opper/vertexai/gemini-3.7-flash-eu`   | 1.0M    |       |           |       |       |       | $0.75      | $4          |
| `opper/xai/grok-4.3`                   | 1.0M    |       |           |       |       |       | $1         | $3          |
| `opper/xai/grok-4.5`                   | 500K    |       |           |       |       |       | $2         | $6          |
| `opper/xai/grok-4.6`                   | 500K    |       |           |       |       |       | $2         | $6          |
| `opper/xai/grok-build-0.1`             | 256K    |       |           |       |       |       | $1         | $2          |

## Advanced configuration

### Custom headers

```typescript
const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "https://api.opper.ai/v3/compat",
    id: "opper/anthropic/claude-fable-5",
    apiKey: process.env.OPPER_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
      ? "opper/xai/grok-build-0.1"
      : "opper/anthropic/claude-fable-5";
  }
});
```