# AddBuffer<T>(int, Entity)

> Records a command to add a dynamic buffer to an entity.

## Definition

* **Type:** Method
* **Namespace:** [Unity.Entities](/engine/7000.0/script-reference/unity/entities.md)
* **Assembly:** UnityEngine.EntitiesModule

```csharp
public DynamicBuffer<T> AddBuffer<T>(int sortKey, Entity e) where T : unmanaged, IBufferElementData
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): A unique index for each set of commands added to this EntityCommandBuffer across all parallel jobs writing commands to this buffer. The [ChunkIndexInQuery](/engine/7000.0/script-reference/unity/entities/chunkindexinquery.md) provided by [IJobEntity](/engine/7000.0/script-reference/unity/entities/ijobentity.md) is an appropriate value to use for this parameter. In an [IJobChunk](/engine/7000.0/script-reference/unity/entities/ijobchunk.md) pass the 'unfilteredChunkIndex' value from IJobChunk.Execute.**** (\[Entity]\(/engine/7000.0/script-reference/unity/entities/entity)): The entity to add the dynamic buffer to.

### Returns

| Type                                                                                  | Description                                                                                                                               |
| ------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------- |
| [DynamicBuffer\<T>](/engine/7000.0/script-reference/unity/entities/dynamicbuffer1.md) | The [DynamicBuffer\<T>](/engine/7000.0/script-reference/unity/entities/dynamicbuffer1.md) that will be added when the command plays back. |

### Remarks

At playback, if the entity already has this type of dynamic buffer, this method sets the dynamic buffer contents. If the entity doesn't have a [DynamicBuffer\<T>](/engine/7000.0/script-reference/unity/entities/dynamicbuffer1.md) component that stores elements of type T, then this method adds a DynamicBuffer component with the provided contents. If the entity is destroyed before playback, an error is thrown.