# `IndicesMigrateReindexMigrateReindex` [interface-IndicesMigrateReindexMigrateReindex]

| Name | Type | Description |
| - | - | - |
| `mode` | [IndicesMigrateReindexModeEnum](./IndicesMigrateReindexModeEnum.md) | Reindex mode. Currently only 'upgrade' is supported. |
| `source` | [IndicesMigrateReindexSourceIndex](./IndicesMigrateReindexSourceIndex.md) | The source index or data stream (only data streams are currently supported). |