# `IngestJoinProcessor` [interface-IngestJoinProcessor]

| Name | Type | Description |
| - | - | - |
| `field` | [Field](./Field.md) | Field containing array values to join. |
| `separator` | string | The separator character. |
| `target_field` | [Field](./Field.md) | The field to assign the joined value to. By default, the field is updated in-place. |