<!-- Extension API v0 — pre-1.0. Interfaces may change without notice until P2 seals the custom-code format. First-party extensions track HEAD. -->

# `theme.install`

Install a theme version for this store (first-party or a visible pack). Does not change the live look until a switch is published.

- **scope**: `design:write`
- **storefront-visible** (bumps the catalog generation): no
- **destructive**: no

## Payload

| field | type | required | notes |
|---|---|---|---|
| `themeId` | string (/^[a-z][a-z0-9-]*\.[a-z][a-z0-9-]*$/, ≤80 chars) | yes |  |
| `version` | string (/^\d+\.\d+\.\d+$/) | no |  |

### JSON Schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "themeId": {
      "type": "string",
      "maxLength": 80,
      "pattern": "^[a-z][a-z0-9-]*\\.[a-z][a-z0-9-]*$"
    },
    "version": {
      "type": "string",
      "pattern": "^\\d+\\.\\d+\\.\\d+$"
    }
  },
  "required": [
    "themeId"
  ],
  "additionalProperties": false
}
```