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

# `catalog.product.setVariants`

Wholesale-replace a product's variant STRUCTURE (order = array order). Existing variants update title/sku only; initial price/stock allowed solely for new variants.

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

## Payload

| field | type | required | notes |
|---|---|---|---|
| `productId` | string (/^prd_[a-zA-Z0-9]{1,32}$/) | yes |  |
| `variants` | array<object> (≤100) | yes |  |

### JSON Schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "productId": {
      "type": "string",
      "pattern": "^prd_[a-zA-Z0-9]{1,32}$"
    },
    "variants": {
      "maxItems": 100,
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string",
            "pattern": "^var_[a-zA-Z0-9]{1,32}$"
          },
          "title": {
            "type": "string",
            "minLength": 1,
            "maxLength": 80
          },
          "sku": {
            "type": "string",
            "minLength": 1,
            "maxLength": 48
          },
          "price": {
            "type": "integer",
            "minimum": 0,
            "maximum": 10000000000000
          },
          "stock": {
            "anyOf": [
              {
                "type": "integer",
                "minimum": 0,
                "maximum": 9007199254740991
              },
              {
                "type": "null"
              }
            ]
          }
        },
        "required": [
          "title"
        ],
        "additionalProperties": false
      }
    }
  },
  "required": [
    "productId",
    "variants"
  ],
  "additionalProperties": false
}
```