{
  "summary": "Bulk update subscriber custom field values",
  "method": "POST",
  "path": "/v4/bulk/custom_fields/subscribers",
  "tag": "Custom Fields",
  "request_body": {
    "custom_field_values": [
      {
        "subscriber_id": 1,
        "subscriber_custom_field_id": 1,
        "value": "string"
      }
    ],
    "callback_url": null
  },
  "response": {
    "custom_field_values": [
      {
        "subscriber_id": 1,
        "subscriber_custom_field_id": 1,
        "value": "string"
      }
    ],
    "failures": [
      {
        "errors": [
          null
        ],
        "custom_field_value": {
          "subscriber_id": null,
          "subscriber_custom_field_id": null,
          "value": null
        }
      }
    ]
  }
}