> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stateset.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Write to a supervised process stdin

> Bytes written

> [!WARNING]
>
> **Confirm your deployment before running this request.** This page describes an API contract;
> a published reference does not establish hosted availability. Check the dated
> [host report](/api-reference/hosts) and obtain your deployment URL and credentials.
> Replace the example host if your provisioned service uses a different URL.

### Path parameters

**id** `string (uuid)` *required*

Sandbox identifier

**processId** `string` *required*

Process identifier (proc\_...)

### Request body

`ProcessStdinRequest`

**data** `string`

Default: `''`. Maximum length: `699052`.

**eof** `boolean`

Default: `false`.

### Response

No response body. Bytes written.

### Status codes

| Code | Meaning |
| - | - |
| `200` | Bytes written |
| `409` | Process not running or started without stdin |

### Using this contract

Read the [source OpenAPI document](/spec/sandbox.json) for declared schemas and alternatives.
This page also includes documented corrections from the [spec overlays](https://github.com/stateset/docs/tree/main/spec/overlays).
Example IDs and values are illustrative; replace them with records from your workspace.

```bash cURL theme={null}
curl --silent --show-error --fail-with-body --request POST \
  --url 'https://api.sandbox.stateset.app/api/v1/sandbox/{id}/processes/{processId}/stdin' \
  --header 'Authorization: ApiKey YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "data": "",
  "eof": false
}'
```


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