# Set a variable

`PUT /v1/environments/{environment}/vars/{key}`

**In this build:** Real.

**Scope:** `environment.write`

**CLI:** `harebox env var set`

## Request: `SecretValue`

| Field | Type | Notes |
|---|---|---|
| `value` (required) | `string` |  |

## Response: 204

No content.

Errors follow [one format](../errors.html).