> ## Documentation Index
> Fetch the complete documentation index at: https://docs.endstate.io/llms.txt
> Use this file to discover all available pages before exploring further.

# isEndstateApiError

> True when the API replied with an error envelope, whatever the code.

```ts theme={null}
isEndstateApiError(value: unknown): value is EndstateApiError
```

## Example

```ts theme={null}
if (isEndstateApiError(error)) log(error.code, error.requestId);
```