A `Functions` instance.

**Signature:**

    export interface Functions 

## Properties

| Property | Type | Description |
|---|---|---|
| [app](https://firebase.google.com/docs/reference/js/functions.functions#functionsapp) | [FirebaseApp](https://firebase.google.com/docs/reference/js/app.firebaseapp#firebaseapp_interface) | The [FirebaseApp](https://firebase.google.com/docs/reference/js/app.firebaseapp#firebaseapp_interface) this `Functions` instance is associated with. |
| [customDomain](https://firebase.google.com/docs/reference/js/functions.functions#functionscustomdomain) | string \| null | A custom domain hosting the callable Cloud Functions. ex: https://mydomain.com |
| [region](https://firebase.google.com/docs/reference/js/functions.functions#functionsregion) | string | The region the callable Cloud Functions are located in. Default is `us-central-1`. |

## Functions.app

The [FirebaseApp](https://firebase.google.com/docs/reference/js/app.firebaseapp#firebaseapp_interface) this `Functions` instance is associated with.

**Signature:**

    app: FirebaseApp;

## Functions.customDomain

A custom domain hosting the callable Cloud Functions. ex: https://mydomain.com

**Signature:**

    customDomain: string | null;

## Functions.region

The region the callable Cloud Functions are located in. Default is `us-central-1`.

**Signature:**

    region: string;