---
url: 'https://adk.nht.io/api/@nhtio/adk/exceptions/variables/E_NOT_A_MEDIA_READER.md'
description: >-
  Thrown when a Media is constructed with a value that does not implement the
  MediaReader interface.
---

# Variable: E\_NOT\_A\_MEDIA\_READER

```ts
const E_NOT_A_MEDIA_READER: CreatedException<[]>;
```

Defined in: [lib/exceptions/runtime.ts:328](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/exceptions/runtime.ts#L328)

Thrown when a Media is constructed with a value that does not implement the MediaReader
interface.

## Remarks

Validated at construction time. Passing anything that lacks `stream` or `byteLength` as
callable functions signals a programming error in the caller.