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

# `metafield.definition.update`

Update a metafield definition's label, description, or validations (type/key are immutable).

- **scope**: `store:admin`
- **storefront-visible** (bumps the catalog generation): no
- **destructive**: no

## Payload

| field | type | required | notes |
|---|---|---|---|
| `id` | string (/^mfd_[0-9A-HJKMNP-TV-Z]{26}$/) | yes |  |
| `patch` | object | yes |  |
| `  labelTR` | string (≤100 chars) | no |  |
| `  descriptionTR` | string (≤500 chars) | no |  |
| `  validations` | object | no |  |
| `    min` | number | no |  |
| `    max` | number | no |  |
| `    maxLength` | integer (..65536) | no |  |
| `    regex` | string (≤200 chars) | no |  |
| `    choices` | array<string (≤100 chars)> (≤50) | no |  |

### JSON Schema

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^mfd_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "patch": {
      "type": "object",
      "properties": {
        "labelTR": {
          "type": "string",
          "minLength": 1,
          "maxLength": 100
        },
        "descriptionTR": {
          "type": "string",
          "maxLength": 500
        },
        "validations": {
          "type": "object",
          "properties": {
            "min": {
              "type": "number"
            },
            "max": {
              "type": "number"
            },
            "maxLength": {
              "type": "integer",
              "exclusiveMinimum": 0,
              "maximum": 65536
            },
            "regex": {
              "type": "string",
              "maxLength": 200
            },
            "choices": {
              "minItems": 1,
              "maxItems": 50,
              "type": "array",
              "items": {
                "type": "string",
                "maxLength": 100
              }
            }
          },
          "additionalProperties": false
        }
      },
      "additionalProperties": false
    }
  },
  "required": [
    "id",
    "patch"
  ],
  "additionalProperties": false
}
```