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[Home](./index) &gt; [valkyrie-js](./valkyrie-js) &gt; [api](./valkyrie-js.api) &gt; [isAPIError](./valkyrie-js.api.isapierror)

## api.isAPIError() function

**Signature:**

```typescript
export declare function isAPIError(reason: any): reason is APIError;
```

## Parameters

|  Parameter | Type | Description |
|  --- | --- | --- |
|  reason | any |  |

**Returns:**

reason is [APIError](./valkyrie-js.api.apierror)