# `IndicesUpdateAliasesAddAction` [interface-IndicesUpdateAliasesAddAction]

| Name | Type | Description |
| - | - | - |
| `alias` | [IndexAlias](./IndexAlias.md) | Alias for the action. Index alias names support date math. |
| `aliases` | [IndexAlias](./IndexAlias.md) | [IndexAlias](./IndexAlias.md)[] | Aliases for the action. Index alias names support date math. |
| `filter` | [QueryDslQueryContainer](./QueryDslQueryContainer.md) | Query used to limit documents the alias can access. |
| `index_routing` | [Routing](./Routing.md) | Value used to route indexing operations to a specific shard. If specified, this overwrites the `routing` value for indexing operations. Data stream aliases don’t support this parameter. |
| `index` | [IndexName](./IndexName.md) | Data stream or index for the action. Supports wildcards ( `*`). |
| `indices` | [Indices](./Indices.md) | Data streams or indices for the action. Supports wildcards ( `*`). |
| `is_hidden` | boolean | If `true`, the alias is hidden. |
| `is_write_index` | boolean | If `true`, sets the write index or data stream for the alias. |
| `must_exist` | boolean | If `true`, the alias must exist to perform the action. |
| `routing` | [Routing](./Routing.md) | Value used to route indexing and search operations to a specific shard. Data stream aliases don’t support this parameter. |
| `search_routing` | [Routing](./Routing.md) | Value used to route search operations to a specific shard. If specified, this overwrites the `routing` value for search operations. Data stream aliases don’t support this parameter. |