# Function: isObservable()

> 

> **isObservable**(`x`): `x is Observable<unknown, unknown>`

Defined in: [packages/server/src/observable/observable.ts:21](https://github.com/trpc/trpc/blob/7c907acfd8b31929214792e3b8c2ad7a8ac72563/packages/server/src/observable/observable.ts#L21)

Whether a value is an observable: an object with `subscribe`.

## Parameters

| Parameter | Type |
| ------ | ------ |
| `x` | `unknown` |

## Returns

`x is Observable<unknown, unknown>`