# Create agent

URL: https://docs.hanzo.ai/docs/openapi/sandbox/post-sandbox-by-id-agent

> Says what to do on a sandbox you hold, and a model does it there while you watch: a shell on any sandbox, and on a desktop or a browser the screen too — it takes a screenshot, clicks where it sees, types, presses keys, opens addresses and runs commands.

`POST /v1/sandbox/{id}/agent`

> [Sandbox →](https://docs.hanzo.ai/docs/openapi/sandbox) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides)

|               |                                              |
| ------------- | -------------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/sandbox/{id}/agent` |
| **Method**    | `POST`                                       |
| **Operation** | `post_sandbox_by_id_agent`                   |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`       |

Says what to do on a sandbox you hold, and a model does it there while you watch: a shell on any sandbox, and on a desktop or a browser the screen too — it takes a screenshot, clicks where it sees, types, presses keys, opens addresses and runs commands. The answer is a text/event-stream, one event a step, ending with `end`.

The body is JSON: `message` (required, what to do, in words), `history` (the conversation so far, oldest first, each {role: user|assistant, text}) and `model` (a model id from GET /v1/models; empty takes the deployment's).

Events (`event:` name, `data:` JSON): `say` {text} the model's words; `act` {tool, args} a tool it reached for; `result` {tool, ok, text} what the tool answered; `error` {text} the turn could not go on; `end` {rounds} the turn is over. A `: ping` comment every 15 seconds keeps intermediaries from closing the stream.

The server keeps nothing between turns: send the conversation so far as `history` ({role: user|assistant, text}). The model is billed to the caller's account at the gateway's rates, and the sandbox hour is the one the lease already bills. Open the sandbox's screen (POST /v1/sandbox/{id}/screen/ticket) beside it to watch.

409 when the sandbox is not running; 404 for a sandbox you do not hold; 503 where no model gateway is mounted.

## Request

1 field.

| Field | In   | Type   | Required | Description |
| ----- | ---- | ------ | -------- | ----------- |
| `id`  | path | string | yes      |             |

## Response

The document declares no response body for this operation. It answers `200` on success and the platform error shape on failure — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo sandbox agent <id>
```

**SDK**

**.ts**

```ts
import { Configuration, SandboxApi } from 'hanzoai';

const api = new SandboxApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postSandboxByIdAgent({ id: 'id' });
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import SandboxApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = SandboxApi(client).post_sandbox_by_id_agent(id='id')
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.SandboxAPI.PostSandboxByIdAgent(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, sandbox_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = sandbox_api::post_sandbox_by_id_agent(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.SandboxApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new SandboxApi(client).postSandboxByIdAgent();
```

The method above is the one at the current release of the document. `hanzoai@8.5.914` (npm) and `hanzoai@8.5.914` (PyPI) were generated from an earlier release, where this operation carried a different id, so it spells the method differently — regenerating the clients is what makes the two agree. [SDKs →](https://docs.hanzo.ai/docs/sdks)

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/sandbox/<id>/agent \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP reaches **sandbox** through the `sandbox` tool, which names its 18 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them:

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_sandboxes"
         }
       }
     }'
```

---

[Sandbox API](https://docs.hanzo.ai/docs/openapi/sandbox) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)