# Create write

URL: https://docs.hanzo.ai/docs/openapi/sandbox/write-sandbox-file

> Writes bytes to one path in the caller's sandbox, creating parents, and answers the resolved path.

`POST /v1/sandbox/write`

> [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/write` |
| **Method**    | `POST`                                  |
| **Operation** | `write_sandbox_file`                    |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`  |

Writes bytes to one path in the caller's sandbox, creating parents,
and answers the resolved path.

## Request

3 fields, body `application/json` (required).

| Field  | In   | Type   | Required | Description                                                |
| ------ | ---- | ------ | -------- | ---------------------------------------------------------- |
| `data` | body | string | —        | Data is the file's bytes, and replaces whatever was there. |
| `id`   | body | string | —        | ID is the sandbox to write into, from an earlier lease.    |
| `path` | body | string | —        | Path is confined the same way PathIn.Path is.              |

## Response

| Status    | Body            | Meaning |
| --------- | --------------- | ------- |
| `200`     | sandbox.Wrote   | ok      |
| `default` | problem-details | refused |

`200` body — 2 fields.

| Field   | In   | Type            | Always | Description                                                                                                                                                                                              |
| ------- | ---- | --------------- | ------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `bytes` | body | integer (int64) | —      | Bytes is how many bytes the file now holds.                                                                                                                                                              |
| `path`  | body | string          | —      | Path is where the bytes actually landed: the caller's path resolved against the sandbox's working directory (Leased.Workdir), which is what a later read or a shell line inside the sandbox has to name. |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo sandbox write
```

**SDK**

**.ts**

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

const api = new SandboxApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.writeSandboxFile({ data: "<data>", 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).write_sandbox_file(data="<data>", id="<id>")
```

**.go**

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

resp, _, err := client.SandboxAPI.WriteSandboxFile(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::write_sandbox_file(&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).writeSandboxFile();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/sandbox/write \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "data": "<data>",
       "id": "<id>"
     }'
```

**MCP**

Tool `sandbox`, op `write_sandbox_file` — POST the JSON-RPC envelope to `https://api.hanzo.ai/v1/mcp`.

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "sandbox",
         "arguments": {
           "op": "write_sandbox_file",
           "input": {
             "data": "<data>",
             "id": "<id>"
           }
         }
       }
     }'
```

---

[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)