| Name | Type | Description | Notes |
|---|---|---|---|
| field | string | Name of the field to use as the first operand in the filter expression. | |
| key | string | If `field` is `tag`, this field is required to specify `key` inside the tags. | [optional] |
| value | string | Constant value to use as the second operand in the filter expression. This value is required when the relation operator is a binary operator. | [optional] |
| relation | string | Operator of a filter expression. |