# ![OpenCode Zen logo](https://models.dev/logos/opencode.svg)OpenCode Zen

Access 29 OpenCode Zen models through Mastra's model router. Authentication is handled automatically using the `OPENCODE_API_KEY` environment variable.

Learn more in the [OpenCode Zen documentation](https://opencode.ai/docs/zen).

```bash
OPENCODE_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: "opencode/big-pickle"
});

// 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 [OpenCode Zen documentation](https://opencode.ai/docs/zen) for details.

## Models

| Model                         | Context | Tools | Reasoning | Image | Audio | Video | Input $/1M | Output $/1M |
| ----------------------------- | ------- | ----- | --------- | ----- | ----- | ----- | ---------- | ----------- |
| `opencode/big-pickle`         | 200K    |       |           |       |       |       | —          | —           |
| `opencode/claude-3-5-haiku`   | 200K    |       |           |       |       |       | $0.80      | $4          |
| `opencode/claude-haiku-4-5`   | 200K    |       |           |       |       |       | $1         | $5          |
| `opencode/claude-opus-4-1`    | 200K    |       |           |       |       |       | $15        | $75         |
| `opencode/claude-opus-4-5`    | 200K    |       |           |       |       |       | $5         | $25         |
| `opencode/claude-opus-4-6`    | 1.0M    |       |           |       |       |       | $5         | $25         |
| `opencode/claude-sonnet-4`    | 1.0M    |       |           |       |       |       | $3         | $15         |
| `opencode/claude-sonnet-4-5`  | 1.0M    |       |           |       |       |       | $3         | $15         |
| `opencode/gemini-3-flash`     | 1.0M    |       |           |       |       |       | $0.50      | $3          |
| `opencode/gemini-3-pro`       | 1.0M    |       |           |       |       |       | $2         | $12         |
| `opencode/glm-4.6`            | 205K    |       |           |       |       |       | $0.60      | $2          |
| `opencode/glm-4.7`            | 205K    |       |           |       |       |       | $0.60      | $2          |
| `opencode/glm-5`              | 205K    |       |           |       |       |       | $1         | $3          |
| `opencode/gpt-5`              | 400K    |       |           |       |       |       | $1         | $9          |
| `opencode/gpt-5-codex`        | 400K    |       |           |       |       |       | $1         | $9          |
| `opencode/gpt-5-nano`         | 400K    |       |           |       |       |       | —          | —           |
| `opencode/gpt-5.1`            | 400K    |       |           |       |       |       | $1         | $9          |
| `opencode/gpt-5.1-codex`      | 400K    |       |           |       |       |       | $1         | $9          |
| `opencode/gpt-5.1-codex-max`  | 400K    |       |           |       |       |       | $1         | $10         |
| `opencode/gpt-5.1-codex-mini` | 400K    |       |           |       |       |       | $0.25      | $2          |
| `opencode/gpt-5.2`            | 400K    |       |           |       |       |       | $2         | $14         |
| `opencode/gpt-5.2-codex`      | 400K    |       |           |       |       |       | $2         | $14         |
| `opencode/kimi-k2`            | 262K    |       |           |       |       |       | $0.40      | $3          |
| `opencode/kimi-k2-thinking`   | 262K    |       |           |       |       |       | $0.40      | $3          |
| `opencode/kimi-k2.5`          | 262K    |       |           |       |       |       | $0.60      | $3          |
| `opencode/kimi-k2.5-free`     | 262K    |       |           |       |       |       | —          | —           |
| `opencode/minimax-m2.1`       | 205K    |       |           |       |       |       | $0.30      | $1          |
| `opencode/minimax-m2.5`       | 205K    |       |           |       |       |       | $0.30      | $1          |
| `opencode/minimax-m2.5-free`  | 205K    |       |           |       |       |       | —          | —           |

## Advanced Configuration

### Custom Headers

```typescript
const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "https://opencode.ai/zen/v1",
    id: "opencode/big-pickle",
    apiKey: process.env.OPENCODE_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
      ? "opencode/minimax-m2.5-free"
      : "opencode/big-pickle";
  }
});
```