---
url: >-
  https://adk.nht.io/api/@nhtio/adk/batteries/media/functions/buildEngineRegistry.md
---

# Function: buildEngineRegistry()

```ts
function buildEngineRegistry(
  engines: readonly MediaEngine[],
  selection?: readonly EngineSelectionMiddlewareFn[],
): EngineRegistry;
```

Defined in: [src/batteries/media/registry.ts:195](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/media/registry.ts#L195)

Build the registry over a resolved, validated engine array.

## Parameters

| Parameter   | Type                                                                                       | Default value | Description                                                                  |
| ----------- | ------------------------------------------------------------------------------------------ | ------------- | ---------------------------------------------------------------------------- |
| `engines`   | readonly [`MediaEngine`](../contracts/interfaces/MediaEngine.md)\[]                         | `undefined`   | The engines, in supply (priority) order.                                     |
| `selection` | readonly [`EngineSelectionMiddlewareFn`](../type-aliases/EngineSelectionMiddlewareFn.md)\[] | `[]`          | Optional selection-middleware stages arbitrating multi-candidate dispatches. |

## Returns

[`EngineRegistry`](../interfaces/EngineRegistry.md)

The registry.