{
  "fields": {
    "summary": {
      "required": false,
      "schema": {
        "type": "array",
        "items": "option",
        "custom": "com.atlassian.jira.plugin.system.customfieldtypes:multiselect",
        "customId": 10001
      },
      "name": "My Multi Select",
      "operations": [
      "set",
      "add"
      ],
      "allowedValues": [
      "red",
      "blue"
      ]
    }
  }
}